Paul Ehrlich

All Publications

• Mutilation of the tree of life via mass extinction of animal genera. Proceedings of the National Academy of Sciences of the United States of America Ceballos, G., Ehrlich, P. R. 2023; 120 (39): e2306987120

  Abstract

  Mass extinctions during the past 500 million y rapidly removed branches from the phylogenetic tree of life and required millions of years for evolution to generate functional replacements for the extinct (EX) organisms. Here we show, by examining 5,400 vertebrate genera (excluding fishes) comprising 34,600 species, that 73 genera became EX since 1500 AD. Beyond any doubt, the human-driven sixth mass extinction is more severe than previously assessed and is rapidly accelerating. The current generic extinction rates are 35 times higher than expected background rates prevailing in the last million years under the absence of human impacts. The genera lost in the last five centuries would have taken some 18,000 y to vanish in the absence of human beings. Current generic extinction rates will likely greatly accelerate in the next few decades due to drivers accompanying the growth and consumption of the human enterprise such as habitat destruction, illegal trade, and climate disruption. If all now-endangered genera were to vanish by 2,100, extinction rates would be 354 (average) or 511 (for mammals) times higher than background rates, meaning that genera lost in three centuries would have taken 106,000 and 153,000 y to become EX in the absence of humans. Such mutilation of the tree of life and the resulting loss of ecosystem services provided by biodiversity to humanity is a serious threat to the stability of civilization. Immediate political, economic, and social efforts of an unprecedented scale are essential if we are to prevent these extinctions and their societal impacts.

  View details for DOI 10.1073/pnas.2306987120

  View details for PubMedID 37722053

• Circling the drain: the extinction crisis and the future of humanity. Philosophical transactions of the Royal Society of London. Series B, Biological sciences Dirzo, R., Ceballos, G., Ehrlich, P. R. 2022; 377 (1857): 20210378

  Abstract

  Humanity has triggered the sixth mass extinction episode since the beginning of the Phanerozoic. The complexity of this extinction crisis is centred on the intersection of two complex adaptive systems: human culture and ecosystem functioning, although the significance of this intersection is not properly appreciated. Human beings are part of biodiversity and elements in a global ecosystem. Civilization, and perhaps even the fate of our species, is utterly dependent on that ecosystem's proper functioning, which society is increasingly degrading. The crisis seems rooted in three factors. First, relatively few people globally are aware of its existence. Second, most people who are, and even many scientists, assume incorrectly that the problem is primarily one of the disappearance of species, when it is the existential threat of myriad population extinctions. Third, while concerned scientists know there are many individual and collective steps that must be taken to slow population extinction rates, some are not willing to advocate the one fundamental, necessary, 'simple' cure, that is, reducing the scale of the human enterprise. We argue that compassionate shrinkage of the human population by further encouraging lower birth rates while reducing both inequity and aggregate wasteful consumption-that is, an end to growthmania-will be required. This article is part of the theme issue 'Ecological complexity and the biosphere: the next 30 years'.

  View details for DOI 10.1098/rstb.2021.0378

  View details for PubMedID 35757873

• Returning to "Normal"? Evolutionary Roots of the Human Prospect. Bioscience Ehrlich, P. R., Ehrlich, A. H. 2022; 72 (8): 778-788

  View details for DOI 10.1093/biosci/biac044

  View details for PubMedID 35923190

  View details for PubMedCentralID PMC9343229

• Scientists' warning on population. The Science of the total environment Crist, E., Ripple, W. J., Ehrlich, P. R., Rees, W. E., Wolf, C. 2022: 157166

  Abstract

  Humanity must commit to transformative change on all levels in order to address the climate emergency and biodiversity collapse. In particular, stabilizing and ultimately reducing the human population size is necessary to ensure the long-term wellbeing of our species and other life on Earth. We show how this transition can be accomplished in an equitable framework that promotes human rights. Specifically, we issue a global appeal for women and men to have at most one child and call for policy-makers to implement population policies that improve education for girls and young women and ensure the availability of high-quality family-planning services.

  View details for DOI 10.1016/j.scitotenv.2022.157166

  View details for PubMedID 35803428

• Returning to "Normal"? Evolutionary Roots of the Human Prospect BIOSCIENCE Ehrlich, P. R., Ehrlich, A. H. 2022

  View details for DOI 10.1093/biosci/biac044

  View details for Web of Science ID 000819493700001

• CropPol: a dynamic, open and global database on crop pollination. Ecology Allen-Perkins, A., Magrach, A., Dainese, M., Garibaldi, L. A., Kleijn, D., Rader, R., Reilly, J. R., Winfree, R., Lundin, O., McGrady, C. M., Brittain, C., Biddinger, D. J., Artz, D. R., Elle, E., Hoffman, G., Ellis, J. D., Daniels, J., Gibbs, J., Campbell, J. W., Brokaw, J., Wilson, J. K., Mason, K., Ward, K. L., Gundersen, K. B., Bobiwash, K., Gut, L., Rowe, L. M., Boyle, N. K., Williams, N. M., Joshi, N. K., Rothwell, N., Gillespie, R. L., Isaacs, R., Fleischer, S. J., Peterson, S. S., Rao, S., Pitts-Singer, T. L., Fijen, T., Boreux, V., Rundlof, M., Viana, B. F., Klein, A., Smith, H. G., Bommarco, R., Carvalheiro, L. G., Ricketts, T. H., Ghazoul, J., Krishnan, S., Benjamin, F. E., Loureiro, J., Castro, S., Raine, N. E., de Groot, G. A., Horgan, F. G., Hipolito, J., Smagghe, G., Meeus, I., Eeraerts, M., Potts, S. G., Kremen, C., Garcia, D., Minarro, M., Crowder, D. W., Pisanty, G., Mandelik, Y., Vereecken, N. J., Leclercq, N., Weekers, T., Lindstrom, S. A., Stanley, D. A., Zaragoza-Trello, C., Nicholson, C. C., Scheper, J., Rad, C., Marks, E. A., Mota, L., Danforth, B., Park, M., Bezerra, A. D., Freitas, B. M., Mallinger, R. E., da Silva, F. O., Willcox, B., Ramos, D. L., da Silva E Silva, F. D., Lazaro, A., Alomar, D., Gonzalez-Estevez, M. A., Taki, H., Cariveau, D. P., Garratt, M. P., Nabaes Jodar, D. N., Stewart, R. I., Ariza, D., Pisman, M., Lichtenberg, E. M., Schuepp, C., Herzog, F., Entling, M. H., Dupont, Y. L., Michener, C. D., Daily, G. C., Ehrlich, P. R., Burns, K. L., Vila, M., Robson, A., Howlett, B., Blechschmidt, L., Jauker, F., Schwarzbach, F., Nesper, M., Diekotter, T., Wolters, V., Castro, H., Gaspar, H., Nault, B. A., Badenhausser, I., Petersen, J. D., Tscharntke, T., Bretagnolle, V., Chan, D. S., Chacoff, N., Andersson, G. K., Jha, S., Colville, J. F., Veldtman, R., Coutinho, J., Bianchi, F. J., Sutter, L., Albrecht, M., Jeanneret, P., Zou, Y., Averill, A. L., Saez, A., Sciligo, A. R., Vergara, C. H., Bloom, E. H., Oeller, E., Badano, E. I., Loeb, G. M., Grab, H., Ekroos, J., Gagic, V., Cunningham, S. A., Astrom, J., Cavigliasso, P., Trillo, A., Classen, A., Mauchline, A. L., Montero-Castano, A., Wilby, A., Woodcock, B. A., Sidhu, C. S., Steffan-Dewenter, I., Vogiatzakis, I. N., Herrera, J. M., Otieno, M., Gikungu, M. W., Cusser, S. J., Nauss, T., Nilsson, L., Knapp, J., Ortega-Marcos, J. J., Gonzalez, J. A., Osborne, J. L., Blanche, R., Shaw, R. F., Hevia, V., Stout, J., Arthur, A. D., Blochtein, B., Szentgyorgyi, H., Li, J., Mayfield, M. M., Woyciechowski, M., Nunes-Silva, P., de Oliveira, R. H., Henry, S., Simmons, B. I., Dalsgaard, B., Hansen, K., Sritongchuay, T., O'Reilly, A. D., Garcia, F. J., Parra, G. N., Pigozo, C. M., Bartomeus, I. 1800

  Abstract

  Seventy five percent of the world's food crops benefit from insect pollination. Hence, there has been increased interest in how global change drivers impact this critical ecosystem service. Because standardized data on crop pollination are rarely available, we are limited in our capacity to understand the variation in pollination benefits to crop yield, as well as to anticipate changes in this service, develop predictions, and inform management actions. Here, we present CropPol, a dynamic, open and global database on crop pollination. It contains measurements recorded from 202 crop studies, covering 3,394 field observations, 2,552 yield measurements (i.e. berry weight, number of fruits and kg per hectare, among others), and 47,752 insect records from 48 commercial crops distributed around the globe. CropPol comprises 32 of the 87 leading global crops and commodities that are pollinator dependent. Malus domestica is the most represented crop (32 studies), followed by Brassica napus (22 studies), Vaccinium corymbosum (13 studies), and Citrullus lanatus (12 studies). The most abundant pollinator guilds recorded are honey bees (34.22% counts), bumblebees (19.19%), flies other than Syrphidae and Bombyliidae (13.18%), other wild bees (13.13%), beetles (10.97%), Syrphidae (4.87%), and Bombyliidae (0.05%). Locations comprise 34 countries distributed among Europe (76 studies), Northern America (60), Latin America and the Caribbean (29), Asia (20), Oceania (10), and Africa (7). Sampling spans three decades and is concentrated on 2001-05 (21 studies), 2006-10 (40), 2011-15 (88), and 2016-20 (50). This is the most comprehensive open global data set on measurements of crop flower visitors, crop pollinators and pollination to date, and we encourage researchers to add more datasets to this database in the future. This data set is released for non-commercial use only. Credits should be given to this paper (i.e., proper citation), and the products generated with this database should be shared under the same license terms (CC BY-NC-SA). This article is protected by copyright. All rights reserved.

  View details for DOI 10.1002/ecy.3614

  View details for PubMedID 34921678

• Why no mention of overpopulation in talk of food systems? NATURE Kunnas, J. 2021; 598 (7880): 257

  View details for DOI 10.1038/d41586-021-02751-9

  View details for Web of Science ID 000706739700012

  View details for PubMedID 34642475

• Why no mention of overpopulation in talk of food systems? NATURE Ehrlich, P. R. 2021; 598 (7880): 257

  View details for DOI 10.1038/d41586-021-02750-w

  View details for Web of Science ID 000706739700010

• Governance in the Face of Extreme Events: Lessons from Evolutionary Processes for Structuring Interventions, and the Need to Go Beyond ECOSYSTEMS Levin, S. A., Anderies, J. M., Adger, N., Barrett, S., Bennett, E. M., Cardenas, J., Carpenter, S. R., Crepin, A., Ehrlich, P., Fischer, J., Folke, C., Kautsky, N., Kling, C., Nyborg, K., Polasky, S., Scheffer, M., Segerson, K., Shogren, J., van den Bergh, J., Walker, B., Weber, E. U., Wilen, J. 2021: 1-15

  Abstract

  The increasing frequency of extreme events, exogenous and endogenous, poses challenges for our societies. The current pandemic is a case in point; but "once-in-a-century" weather events are also becoming more common, leading to erosion, wildfire and even volcanic events that change ecosystems and disturbance regimes, threaten the sustainability of our life-support systems, and challenge the robustness and resilience of societies. Dealing with extremes will require new approaches and large-scale collective action. Preemptive measures can increase general resilience, a first line of protection, while more specific reactive responses are developed. Preemptive measures also can minimize the negative effects of events that cannot be avoided. In this paper, we first explore approaches to prevention, mitigation and adaptation, drawing inspiration from how evolutionary challenges have made biological systems robust and resilient, and from the general theory of complex adaptive systems. We argue further that proactive steps that go beyond will be necessary to reduce unacceptable consequences.

  View details for DOI 10.1007/s10021-021-00680-2

  View details for Web of Science ID 000693526700002

  View details for PubMedID 34512142

  View details for PubMedCentralID PMC8422834

• A Call to Action: Marshaling Science for Society BIOSCIENCE Fenster, C. B., Anderson, G. J., Berenbaum, M. R., Burris, J. E., Collins, J. P., Colwell, R. R., Cracraft, J., Covich, A. P., Ehrlich, P. R., Eshbaugh, W., James, F. C., Futuyma, D. J., Holsinger, K. E., Likens, G. E., Lovejoy, T. E., Mooney, H. A., Raven, P. H., Smith, K. C., Stafford, S. G., Strain, B. R., Travis, J., Wake, M. H., Wall, D. H., Weis, J. S. 2021; 71 (1): 7–8

  View details for DOI 10.1093/biosci/biaa138

  View details for Web of Science ID 000609888900003

• WTO must ban harmful fisheries subsidies. Science (New York, N.Y.) Sumaila, U. R., Skerritt, D. J., Schuhbauer, A., Villasante, S., Cisneros-Montemayor, A. M., Sinan, H., Burnside, D., Abdallah, P. R., Abe, K., Addo, K. A., Adelsheim, J., Adewumi, I. J., Adeyemo, O. K., Adger, N., Adotey, J., Advani, S., Afrin, Z., Aheto, D., Akintola, S. L., Akpalu, W., Alam, L., Alava, J. J., Allison, E. H., Amon, D. J., Anderies, J. M., Anderson, C. M., Andrews, E., Angelini, R., Anna, Z., Antweiler, W., Arizi, E. K., Armitage, D., Arthur, R. I., Asare, N., Asche, F., Asiedu, B., Asuquo, F., Badmus, L., Bailey, M., Ban, N., Barbier, E. B., Barley, S., Barnes, C., Barrett, S., Basurto, X., Belhabib, D., Bennett, E., Bennett, N. J., Benzaken, D., Blasiak, R., Bohorquez, J. J., Bordehore, C., Bornarel, V., Boyd, D. R., Breitburg, D., Brooks, C., Brotz, L., Campbell, D., Cannon, S., Cao, L., Cardenas Campo, J. C., Carpenter, S., Carpenter, G., Carson, R. T., Carvalho, A. R., Castrejón, M., Caveen, A. J., Chabi, M. N., Chan, K. M., Chapin, F. S., Charles, T., Cheung, W., Christensen, V., Chuku, E. O., Church, T., Clark, C., Clarke, T. M., Cojocaru, A. L., Copeland, B., Crawford, B., Crépin, A. S., Crowder, L. B., Cury, P., Cutting, A. N., Daily, G. C., Da-Rocha, J. M., Das, A., de la Puente, S., de Zeeuw, A., Deikumah, S. K., Deith, M., Dewitte, B., Doubleday, N., Duarte, C. M., Dulvy, N. K., Eddy, T., Efford, M., Ehrlich, P. R., Elsler, L. G., Fakoya, K. A., Falaye, A. E., Fanzo, J., Fitzsimmons, C., Flaaten, O., Florko, K. R., Aviles, M. F., Folke, C., Forrest, A., Freeman, P., Freire, K. M., Froese, R., Frölicher, T. L., Gallagher, A., Garcon, V., Gasalla, M. A., Gephart, J. A., Gibbons, M., Gillespie, K., Giron-Nava, A., Gjerde, K., Glaser, S., Golden, C., Gordon, L., Govan, H., Gryba, R., Halpern, B. S., Hanich, Q., Hara, M., Harley, C. D., Harper, S., Harte, M., Helm, R., Hendrix, C., Hicks, C. C., Hood, L., Hoover, C., Hopewell, K., Horta E Costa, B. B., Houghton, J. D., Iitembu, J. A., Isaacs, M., Isahaku, S., Ishimura, G., Islam, M., Issifu, I., Jackson, J., Jacquet, J., Jensen, O. P., Ramon, J. J., Jin, X., Jonah, A., Jouffray, J. B., Juniper, S. K., Jusoh, S., Kadagi, I., Kaeriyama, M., Kaiser, M. J., Kaiser, B. A., Kakujaha-Matundu, O., Karuaihe, S. T., Karumba, M., Kemmerly, J. D., Khan, A. S., Kimani, P., Kleisner, K., Knowlton, N., Kotowicz, D., Kurien, J., Kwong, L. E., Lade, S., Laffoley, D., Lam, M. E., Lam, V. W., Lange, G. M., Latif, M. T., Le Billon, P., Le Brenne, V., Le Manach, F., Levin, S. A., Levin, L., Limburg, K. E., List, J., Lombard, A. T., Lopes, P. F., Lotze, H. K., Mallory, T. G., Mangar, R. S., Marszalec, D., Mattah, P., Mayorga, J., McAusland, C., McCauley, D. J., McLean, J., McMullen, K., Meere, F., Mejaes, A., Melnychuk, M., Mendo, J., Micheli, F., Millage, K., Miller, D., Mohamed, K. S., Mohammed, E., Mokhtar, M., Morgan, L., Muawanah, U., Munro, G. R., Murray, G., Mustafa, S., Nayak, P., Newell, D., Nguyen, T., Noack, F., Nor, A. M., Nunoo, F. K., Obura, D., Okey, T., Okyere, I., Onyango, P., Oostdijk, M., Orlov, P., Österblom, H., Owens, D., Owens, T., Oyinlola, M., Pacoureau, N., Pakhomov, E., Abrantes, J. P., Pascual, U., Paulmier, A., Pauly, D., Pèlèbè, R. O., Peñalosa, D., Pennino, M. G., Peterson, G., Pham, T. T., Pinkerton, E., Polasky, S., Polunin, N. V., Prah, E., Ramírez, J., Relano, V., Reygondeau, G., Robadue, D., Roberts, C., Rogers, A., Roumbedakis, K., Sala, E., Scheffer, M., Segerson, K., Seijo, J. C., Seto, K. C., Shogren, J. F., Silver, J. J., Singh, G., Soszynski, A., Splichalova, D. V., Spring, M., Stage, J., Stephenson, F., Stewart, B. D., Sultan, R., Suttle, C., Tagliabue, A., Tall, A., Talloni-Álvarez, N., Tavoni, A., Taylor, D. R., Teh, L. S., Teh, L. C., Thiebot, J. B., Thiele, T., Thilsted, S. H., Thumbadoo, R. V., Tigchelaar, M., Tol, R. S., Tortell, P., Troell, M., Uzmanoğlu, M. S., van Putten, I., van Santen, G., Villaseñor-Derbez, J. C., Wabnitz, C. C., Walsh, M., Walsh, J. P., Wambiji, N., Weber, E. U., Westley, F., Williams, S., Wisz, M. S., Worm, B., Xiao, L., Yagi, N., Yamazaki, S., Yang, H., Zeller, D. 2021; 374 (6567): 544

  Abstract

  [Figure: see text].

  View details for DOI 10.1126/science.abm1680

  View details for PubMedID 34709891

• Corridors of Clarity: Four Principles to Overcome Uncertainty Paralysis in the Anthropocene. Bioscience Polasky, S., Crepin, A., Biggs, R. O., Carpenter, S. R., Folke, C., Peterson, G., Scheffer, M., Barrett, S., Daily, G., Ehrlich, P., Howarth, R. B., Hughes, T., Levin, S. A., Shogren, J. F., Troell, M., Walker, B., Xepapadeas, A. 2020; 70 (12): 1139–44

  Abstract

  Global environmental change challenges humanity because of its broad scale, long-lasting, and potentially irreversible consequences. Key to an effective response is to use an appropriate scientific lens to peer through the mist of uncertainty that threatens timely and appropriate decisions surrounding these complex issues. Identifying such corridors of clarity could help understanding critical phenomena or causal pathways sufficiently well to justify taking policy action. To this end, we suggest four principles: Follow the strongest and most direct path between policy decisions on outcomes, focus on finding sufficient evidence for policy purpose, prioritize no-regrets policies by avoiding options with controversial, uncertain, or immeasurable benefits, aim for getting the big picture roughly right rather than focusing on details.

  View details for DOI 10.1093/biosci/biaa115

  View details for PubMedID 33376456

• Untitled CONSERVATION BIOLOGY Ehrlich, P. R. 2020; 34 (6): 1593

  View details for Web of Science ID 000592645700035

• Jaw Epidemic: A Reply to Singh BIOSCIENCE Kahn, S., Ehrlich, P., Feldman, M., Sapolsky, R., Wong, S. 2020; 70 (12): 1044

  View details for DOI 10.1093/biosci/biaa128

  View details for Web of Science ID 000605704500003

• The Jaw Epidemic: Recognition, Origins, Cures, and Prevention BIOSCIENCE Kahn, S., Ehrlich, P., Feldman, M., Sapolsky, R., Wong, S. 2020; 70 (9): 759–71

  Abstract

  Contemporary humans are living very different lives from those of their ancestors, and some of the changes have had serious consequences for health. Multiple chronic "diseases of civilization," such as cardiovascular problems, cancers, ADHD, and dementias are prevalent, increasing morbidity rates. Stress, including the disruption of traditional sleep patterns by modern lifestyles, plays a prominent role in the etiology of these diseases, including obstructive sleep apnea. Surprisingly, jaw shrinkage since the agricultural revolution, leading to an epidemic of crooked teeth, a lack of adequate space for the last molars (wisdom teeth), and constricted airways, is a major cause of sleep-related stress. Despite claims that the cause of this jaw epidemic is somehow genetic, the speed with which human jaws have changed, especially in the last few centuries, is much too fast to be evolutionary. Correlation in time and space strongly suggests the symptoms are phenotypic responses to a vast natural experiment-rapid and dramatic modifications of human physical and cultural environments. The agricultural and industrial revolutions have produced smaller jaws and less-toned muscles of the face and oropharynx, which contribute to the serious health problems mentioned above. The mechanism of change, research and clinical trials suggest, lies in orofacial posture, the way people now hold their jaws when not voluntarily moving them in speaking or eating and especially when sleeping. The critical resting oral posture has been disrupted in societies no longer hunting and gathering. Virtually all aspects of how modern people function and rest are radically different from those of our ancestors. We also briefly discuss treatment of jaw symptoms and possible clinical cures for individuals, as well as changes in society that might lead to better care and, ultimately, prevention.

  View details for DOI 10.1093/biosci/biaa073

  View details for Web of Science ID 000580986300005

  View details for PubMedID 32973408

  View details for PubMedCentralID PMC7498344

• Reflections on Michael Soule, a visionary for conservation biology CONSERVATION BIOLOGY Crooks, K. R., Mills, L., Sanjayan, M., Ehrlich, P. R., Ogden, J. C., Allendorf, F. W., Ralls, K., Noss, R. F., Mace, G., Estes, J. A., Doak, D. F., Terborgh, J., Inouye, D. W. 2020

  View details for DOI 10.1111/cobi.13597

  View details for Web of Science ID 000558044600001

  View details for PubMedID 32779788

• Donald Kennedy (1931-2020). Science (New York, N.Y.) Daily, G. C., Ehrlich, P. R. 2020; 368 (6495): 1062

  View details for DOI 10.1126/science.abc7807

  View details for PubMedID 32499430

• Vertebrates on the brink as indicators of biological annihilation and the sixth mass extinction. Proceedings of the National Academy of Sciences of the United States of America Ceballos, G., Ehrlich, P. R., Raven, P. H. 2020

  Abstract

  The ongoing sixth mass species extinction is the result of the destruction of component populations leading to eventual extirpation of entire species. Populations and species extinctions have severe implications for society through the degradation of ecosystem services. Here we assess the extinction crisis from a different perspective. We examine 29,400 species of terrestrial vertebrates, and determine which are on the brink of extinction because they have fewer than 1,000 individuals. There are 515 species on the brink (1.7% of the evaluated vertebrates). Around 94% of the populations of 77 mammal and bird species on the brink have been lost in the last century. Assuming all species on the brink have similar trends, more than 237,000 populations of those species have vanished since 1900. We conclude the human-caused sixth mass extinction is likely accelerating for several reasons. First, many of the species that have been driven to the brink will likely become extinct soon. Second, the distribution of those species highly coincides with hundreds of other endangered species, surviving in regions with high human impacts, suggesting ongoing regional biodiversity collapses. Third, close ecological interactions of species on the brink tend to move other species toward annihilation when they disappear-extinction breeds extinctions. Finally, human pressures on the biosphere are growing rapidly, and a recent example is the current coronavirus disease 2019 (Covid-19) pandemic, linked to wildlife trade. Our results reemphasize the extreme urgency of taking much-expanded worldwide actions to save wild species and humanity's crucial life-support systems from this existential threat.

  View details for DOI 10.1073/pnas.1922686117

  View details for PubMedID 32482862

• Social dimensions of fertility behavior and consumption patterns in the Anthropocene. Proceedings of the National Academy of Sciences of the United States of America Barrett, S., Dasgupta, A., Dasgupta, P., Adger, W. N., Anderies, J., van den Bergh, J., Bledsoe, C., Bongaarts, J., Carpenter, S., Chapin, F. S., Crepin, A., Daily, G., Ehrlich, P., Folke, C., Kautsky, N., Lambin, E. F., Levin, S. A., Maler, K., Naylor, R., Nyborg, K., Polasky, S., Scheffer, M., Shogren, J., Jorgensen, P. S., Walker, B., Wilen, J. 2020

  Abstract

  We consider two aspects of the human enterprise that profoundly affect the global environment: population and consumption. We show that fertility and consumption behavior harbor a class of externalities that have not been much noted in the literature. Both are driven in part by attitudes and preferences that are not egoistic but socially embedded; that is, each household's decisions are influenced by the decisions made by others. In a famous paper, Garrett Hardin [G. Hardin, Science 162, 1243-1248 (1968)] drew attention to overpopulation and concluded that the solution lay in people "abandoning the freedom to breed." That human attitudes and practices are socially embedded suggests that it is possible for people to reduce their fertility rates and consumption demands without experiencing a loss in wellbeing. We focus on fertility in sub-Saharan Africa and consumption in the rich world and argue that bottom-up social mechanisms rather than top-down government interventions are better placed to bring about those ecologically desirable changes.

  View details for DOI 10.1073/pnas.1909857117

  View details for PubMedID 32165543

• Michael Soulé (1936-2020). Science (New York, N.Y.) Inouye, D. W., Ehrlich, P. R. 2020; 369 (6505): 777

  View details for DOI 10.1126/science.abd6925

  View details for PubMedID 32792387

• Conservation in human-dominated landscapes: Lessons from the distribution of the Central American squirrel monkey BIOLOGICAL CONSERVATION Ceballos, G., Ehrlich, P. R., Pacheco, J., Valverde-Zuniga, N., Daily, G. C. 2019; 237: 41–49

  View details for DOI 10.1016/j.biocon.2019.06.008

  View details for Web of Science ID 000488314700005

• Long-term declines in bird populations in tropical agricultural countryside PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Sekercioglu, C. H., Mendenhall, C. D., Oviedo-Brenes, F., Horns, J. J., Ehrlich, P. R., Daily, G. C. 2019; 116 (20): 9903–12

  View details for DOI 10.1073/pnas.1802732116

  View details for Web of Science ID 000467804000039

• Role of economics in analyzing the environment and sustainable development. Proceedings of the National Academy of Sciences of the United States of America Polasky, S., Kling, C. L., Levin, S. A., Carpenter, S. R., Daily, G. C., Ehrlich, P. R., Heal, G. M., Lubchenco, J. 2019; 116 (12): 5233–38

  View details for PubMedID 30890656

• The Root of Misaligned Jaws AMERICAN SCIENTIST Kahn, S., Ehrlich, P. R. 2019; 107 (2): 112–19

  View details for Web of Science ID 000458341200022

• Long-term declines in bird populations in tropical agricultural countryside. Proceedings of the National Academy of Sciences of the United States of America Şekercioğlu, Ç. H., Mendenhall, C. D., Oviedo-Brenes, F. n., Horns, J. J., Ehrlich, P. R., Daily, G. C. 2019

  Abstract

  Tropical agriculture is a major driver of biodiversity loss, yet it can provide conservation opportunities, especially where protected areas are inadequate. To investigate the long-term biodiversity capacity of agricultural countryside, we quantified bird population trends in Costa Rica by mist netting 57,255 birds of 265 species between 1999 and 2010 in sun coffee plantations, riparian corridors, secondary forests, forest fragments, and primary forest reserves. More bird populations (69) were declining than were stable (39) or increasing (4). Declines were common in resident, insectivorous, and more specialized species. There was no relationship between the species richness of a habitat and its conservation value. High-value forest bird communities were characterized by their distinct species composition and habitat and dietary functional signatures. While 49% of bird species preferred forest to coffee, 39% preferred coffee to forest and 12% used both habitats, indicating that coffee plantations have some conservation value. Coffee plantations, although lacking most of the forest specialists, hosted 185 bird species, had the highest capture rates, and supported increasing numbers of some forest species. Coffee plantations with higher tree cover (7% vs. 13%) had more species with increasing capture rates, twice as many forest specialists, and half as many nonforest species. Costa Rican countryside habitats, especially those with greater tree cover, host many bird species and are critical for connecting bird populations in forest remnants. Diversified agricultural landscapes can enhance the biodiversity capacity of tropical countryside, but, for the long-term persistence of all forest bird species, large (>1,000 ha) protected areas are essential.

  View details for PubMedID 31036662

• The Great Mismatch BIOSCIENCE Ehrlich, P. R., Blumstein, D. T. 2018; 68 (11): 844–46

  View details for DOI 10.1093/biosci/biy110

  View details for Web of Science ID 000455168300006

• Nature Divided, Scientists United: US-Mexico Border Wall Threatens Biodiversity and Binational Conservation BIOSCIENCE Peters, R., Ripple, W. J., Wolf, C., Moskwik, M., Carreon-Arroyo, G., Ceballos, G., Cordova, A., Dirzo, R., Ehrlich, P. R., Flesch, A. D., List, R., Lovejoy, T. E., Noss, R. F., Pacheco, J., Sarukhan, J. K., Soule, M. E., Wilson, E. O., Miller, J. B. 2018; 68 (10): 740–43

  View details for DOI 10.1093/biosci/biy063

  View details for Web of Science ID 000455168100003

• The misunderstood sixth mass extinction SCIENCE Ceballos, G., Ehrlich, P. R. 2018; 360 (6393): 1080–81

  View details for PubMedID 29880679

• Pessimism on the Food Front SUSTAINABILITY Ehrlich, P. R., Harte, J. 2018; 10 (4)

  View details for DOI 10.3390/su10041120

  View details for Web of Science ID 000435188000224

• Biological annihilation via the ongoing sixth mass extinction signaled by vertebrate population losses and declines PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Ceballos, G., Ehrlich, P. R., Dirzo, R. 2017; 114 (30): E6089–E6096

  Abstract

  The population extinction pulse we describe here shows, from a quantitative viewpoint, that Earth's sixth mass extinction is more severe than perceived when looking exclusively at species extinctions. Therefore, humanity needs to address anthropogenic population extirpation and decimation immediately. That conclusion is based on analyses of the numbers and degrees of range contraction (indicative of population shrinkage and/or population extinctions according to the International Union for Conservation of Nature) using a sample of 27,600 vertebrate species, and on a more detailed analysis documenting the population extinctions between 1900 and 2015 in 177 mammal species. We find that the rate of population loss in terrestrial vertebrates is extremely high-even in "species of low concern." In our sample, comprising nearly half of known vertebrate species, 32% (8,851/27,600) are decreasing; that is, they have decreased in population size and range. In the 177 mammals for which we have detailed data, all have lost 30% or more of their geographic ranges and more than 40% of the species have experienced severe population declines (>80% range shrinkage). Our data indicate that beyond global species extinctions Earth is experiencing a huge episode of population declines and extirpations, which will have negative cascading consequences on ecosystem functioning and services vital to sustaining civilization. We describe this as a "biological annihilation" to highlight the current magnitude of Earth's ongoing sixth major extinction event.

  View details for PubMedID 28696295

• What should conservation biologists be doing? An homage to Ilkka Hanski ANNALES ZOOLOGICI FENNICI Ehrlich, P. R. 2017; 54 (1-4): 7–11

  View details for DOI 10.5735/086.054.0103

  View details for Web of Science ID 000401779600003

• Diversification, Yield and a New Agricultural Revolution: Problems and Prospects SUSTAINABILITY Ponisio, L. C., Ehrlich, P. R. 2016; 8 (11)

  View details for DOI 10.3390/su8111118

  View details for Web of Science ID 000389316200039

• The Climate Change Challenge and Barriers to the Exercise of Foresight Intelligence BIOSCIENCE Ross, L., Arrow, K., Cialdini, R., Diamond-Smith, N., Diamond, J., Dunne, J., Feldman, M., Horn, R., Kennedy, D., Murphy, C., Pirages, D., Smith, K., York, R., Ehrlich, P. 2016; 66 (5): 363-370

  View details for DOI 10.1093/biosci/biw025

  View details for Web of Science ID 000375452600004

• Avoiding collapse: Grand challenges for science and society to solve by 2050 ELEMENTA-SCIENCE OF THE ANTHROPOCENE Barnosky, A. D., Ehrlich, P. R., Hadly, E. A. 2016; 4: 1–9

  View details for DOI 10.12952/journal.elementa.000094

  View details for Web of Science ID 000377458700001

• Charles Duncan Michener, 1918-2015 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Brosi, B. J., Ehrlich, P. R. 2016; 113 (8): 1963–64

  View details for PubMedID 26862171

• Tropical countryside riparian corridors provide critical habitat and connectivity for seed-dispersing forest birds in a fragmented landscape JOURNAL OF ORNITHOLOGY Sekercioglu, C. H., Loarie, S. R., Oviedo-Brenes, F., Mendenhall, C. D., Daily, G. C., Ehrlich, P. R. 2015; 156: S343-S353

  View details for DOI 10.1007/s10336-015-1299-x

  View details for Web of Science ID 000367457200030

• Opinion: To feed the world in 2050 will require a global revolution PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Ehrlich, P. R., Harte, J. 2015; 112 (48): 14743–44

  View details for PubMedID 26627228

• Reply to Kirchhoff: Homogenous and mutually exclusive conservation typologies are neither possible nor desirable PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Karp, D. S., Mendenhall, C. D., Callaway, E., Frishkoff, L. O., Kareiva, P. M., Ehrlich, P. R., Daily, G. C. 2015; 112 (44): E5906

  View details for PubMedID 26483508

• Biophysical limits, women's rights and the climate encyclical NATURE CLIMATE CHANGE Ehrlich, P. R., Harte, J. 2015; 5 (10): 904–5

  View details for DOI 10.1038/nclimate2795

  View details for Web of Science ID 000361840600004

• Confronting and resolving competing values behind conservation objectives PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Karpa, D. S., Mendenhall, C. D., Callaway, E., Frishkoff, L. O., Kareiva, P. M., Ehrlich, P. R., Daily, G. C. 2015; 112 (35): 11132-11137

  Abstract

  Diverse motivations for preserving nature both inspire and hinder its conservation. Optimal conservation strategies may differ radically depending on the objective. For example, creating nature reserves may prevent extinctions through protecting severely threatened species, whereas incentivizing farmland hedgerows may benefit people through bolstering pest-eating or pollinating species. Win-win interventions that satisfy multiple objectives are alluring, but can also be elusive. To achieve better outcomes, we developed and implemented a practical typology of nature conservation framed around seven common conservation objectives. Using an intensively studied bird assemblage in southern Costa Rica as a case study, we applied the typology in the context of biodiversity's most pervasive threat: habitat conversion. We found that rural habitats in a varied tropical landscape, comprising small farms, villages, forest fragments, and forest reserves, provided biodiversity-driven processes that benefit people, such as pollination, seed dispersal, and pest consumption. However, species valued for their rarity, endemism, and evolutionary distinctness declined in farmland. Conserving tropical forest on farmland increased species that international tourists value, but not species discussed in Costa Rican newspapers. Despite these observed trade-offs, our analyses also revealed promising synergies. For example, we found that maintaining forest cover surrounding farms in our study region would likely enhance most conservation objectives at minimal expense to others. Overall, our typology provides a framework for resolving the competing objectives of modern conservation.

  View details for DOI 10.1073/pnas.1504788112

  View details for Web of Science ID 000360383200080

  View details for PubMedCentralID PMC4568250

• Confronting and resolving competing values behind conservation objectives. Proceedings of the National Academy of Sciences of the United States of America Karp, D. S., Mendenhall, C. D., Callaway, E., Frishkoff, L. O., Kareiva, P. M., Ehrlich, P. R., Daily, G. C. 2015; 112 (35): 11132-11137

  Abstract

  Diverse motivations for preserving nature both inspire and hinder its conservation. Optimal conservation strategies may differ radically depending on the objective. For example, creating nature reserves may prevent extinctions through protecting severely threatened species, whereas incentivizing farmland hedgerows may benefit people through bolstering pest-eating or pollinating species. Win-win interventions that satisfy multiple objectives are alluring, but can also be elusive. To achieve better outcomes, we developed and implemented a practical typology of nature conservation framed around seven common conservation objectives. Using an intensively studied bird assemblage in southern Costa Rica as a case study, we applied the typology in the context of biodiversity's most pervasive threat: habitat conversion. We found that rural habitats in a varied tropical landscape, comprising small farms, villages, forest fragments, and forest reserves, provided biodiversity-driven processes that benefit people, such as pollination, seed dispersal, and pest consumption. However, species valued for their rarity, endemism, and evolutionary distinctness declined in farmland. Conserving tropical forest on farmland increased species that international tourists value, but not species discussed in Costa Rican newspapers. Despite these observed trade-offs, our analyses also revealed promising synergies. For example, we found that maintaining forest cover surrounding farms in our study region would likely enhance most conservation objectives at minimal expense to others. Overall, our typology provides a framework for resolving the competing objectives of modern conservation.

  View details for DOI 10.1073/pnas.1504788112

  View details for PubMedID 26283400

• Accelerated modern human-induced species losses: Entering the sixth mass extinction SCIENCE ADVANCES Ceballos, G., Ehrlich, P. R., Barnosky, A. D., Garcia, A., Pringle, R. M., Palmer, T. M. 2015; 1 (5): e1400253

  Abstract

  The oft-repeated claim that Earth's biota is entering a sixth "mass extinction" depends on clearly demonstrating that current extinction rates are far above the "background" rates prevailing between the five previous mass extinctions. Earlier estimates of extinction rates have been criticized for using assumptions that might overestimate the severity of the extinction crisis. We assess, using extremely conservative assumptions, whether human activities are causing a mass extinction. First, we use a recent estimate of a background rate of 2 mammal extinctions per 10,000 species per 100 years (that is, 2 E/MSY), which is twice as high as widely used previous estimates. We then compare this rate with the current rate of mammal and vertebrate extinctions. The latter is conservatively low because listing a species as extinct requires meeting stringent criteria. Even under our assumptions, which would tend to minimize evidence of an incipient mass extinction, the average rate of vertebrate species loss over the last century is up to 100 times higher than the background rate. Under the 2 E/MSY background rate, the number of species that have gone extinct in the last century would have taken, depending on the vertebrate taxon, between 800 and 10,000 years to disappear. These estimates reveal an exceptionally rapid loss of biodiversity over the last few centuries, indicating that a sixth mass extinction is already under way. Averting a dramatic decay of biodiversity and the subsequent loss of ecosystem services is still possible through intensified conservation efforts, but that window of opportunity is rapidly closing.

  View details for PubMedID 26601195

• Transformational change: creating a safe operating space for humanity ECOLOGY AND SOCIETY Mcalpine, C. A., Seabrook, L. M., Ryan, J. G., Feeney, B. J., Ripple, W. J., Ehrlich, A. H., Ehrlich, P. R. 2015; 20 (1)

  View details for DOI 10.5751/ES-07181-200156

  View details for Web of Science ID 000353293900032

• Conservation biology and the endarkenment. Ambio Ehrlich, P. R. 2014; 43 (7): 847-848

  View details for DOI 10.1007/s13280-014-0551-6

  View details for PubMedID 25238979

  View details for PubMedCentralID PMC4190151

• From global change to a butterfly flapping: biophysics and behaviour affect tropical climate change impacts. Proceedings. Biological sciences / The Royal Society Bonebrake, T. C., Boggs, C. L., Stamberger, J. A., Deutsch, C. A., Ehrlich, P. R. 2014; 281 (1793)

  Abstract

  Difficulty in characterizing the relationship between climatic variability and climate change vulnerability arises when we consider the multiple scales at which this variation occurs, be it temporal (from minute to annual) or spatial (from centimetres to kilometres). We studied populations of a single widely distributed butterfly species, Chlosyne lacinia, to examine the physiological, morphological, thermoregulatory and biophysical underpinnings of adaptation to tropical and temperate climates. Microclimatic and morphological data along with a biophysical model documented the importance of solar radiation in predicting butterfly body temperature. We also integrated the biophysics with a physiologically based insect fitness model to quantify the influence of solar radiation, morphology and behaviour on warming impact projections. While warming is projected to have some detrimental impacts on tropical ectotherms, fitness impacts in this study are not as negative as models that assume body and air temperature equivalence would suggest. We additionally show that behavioural thermoregulation can diminish direct warming impacts, though indirect thermoregulatory consequences could further complicate predictions. With these results, at multiple spatial and temporal scales, we show the importance of biophysics and behaviour for studying biodiversity consequences of global climate change, and stress that tropical climate change impacts are likely to be context-dependent.

  View details for DOI 10.1098/rspb.2014.1264

  View details for PubMedID 25165769

• Does aquaculture add resilience to the global food system? Proceedings of the National Academy of Sciences of the United States of America Troell, M., Naylor, R. L., Metian, M., Beveridge, M., Tyedmers, P. H., Folke, C., Arrow, K. J., Barrett, S., Crépin, A., Ehrlich, P. R., Gren, A., Kautsky, N., Levin, S. A., Nyborg, K., Österblom, H., Polasky, S., Scheffer, M., Walker, B. H., Xepapadeas, T., de Zeeuw, A. 2014; 111 (37): 13257-13263

  Abstract

  Aquaculture is the fastest growing food sector and continues to expand alongside terrestrial crop and livestock production. Using portfolio theory as a conceptual framework, we explore how current interconnections between the aquaculture, crop, livestock, and fisheries sectors act as an impediment to, or an opportunity for, enhanced resilience in the global food system given increased resource scarcity and climate change. Aquaculture can potentially enhance resilience through improved resource use efficiencies and increased diversification of farmed species, locales of production, and feeding strategies. However, aquaculture's reliance on terrestrial crops and wild fish for feeds, its dependence on freshwater and land for culture sites, and its broad array of environmental impacts diminishes its ability to add resilience. Feeds for livestock and farmed fish that are fed rely largely on the same crops, although the fraction destined for aquaculture is presently small (∼4%). As demand for high-value fed aquaculture products grows, competition for these crops will also rise, as will the demand for wild fish as feed inputs. Many of these crops and forage fish are also consumed directly by humans and provide essential nutrition for low-income households. Their rising use in aquafeeds has the potential to increase price levels and volatility, worsening food insecurity among the most vulnerable populations. Although the diversification of global food production systems that includes aquaculture offers promise for enhanced resilience, such promise will not be realized if government policies fail to provide adequate incentives for resource efficiency, equity, and environmental protection.

  View details for DOI 10.1073/pnas.1404067111

  View details for PubMedID 25136111

  View details for PubMedCentralID PMC4169979

• Does aquaculture add resilience to the global food system? PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Troell, M., Naylor, R. L., Metian, M., Beveridge, M., Tyedmers, P. H., Folke, C., Arrow, K. J., Barrett, S., Crepin, A., Ehrlich, P. R., Gren, A., Kautsky, N., Levin, S. A., Nyborg, K., Osterblom, H., Polasky, S., Scheffer, M., Walker, B. H., Xepapadeas, T., de Zeeuw, A. 2014; 111 (37): 13257-13263

  Abstract

  Aquaculture is the fastest growing food sector and continues to expand alongside terrestrial crop and livestock production. Using portfolio theory as a conceptual framework, we explore how current interconnections between the aquaculture, crop, livestock, and fisheries sectors act as an impediment to, or an opportunity for, enhanced resilience in the global food system given increased resource scarcity and climate change. Aquaculture can potentially enhance resilience through improved resource use efficiencies and increased diversification of farmed species, locales of production, and feeding strategies. However, aquaculture's reliance on terrestrial crops and wild fish for feeds, its dependence on freshwater and land for culture sites, and its broad array of environmental impacts diminishes its ability to add resilience. Feeds for livestock and farmed fish that are fed rely largely on the same crops, although the fraction destined for aquaculture is presently small (∼4%). As demand for high-value fed aquaculture products grows, competition for these crops will also rise, as will the demand for wild fish as feed inputs. Many of these crops and forage fish are also consumed directly by humans and provide essential nutrition for low-income households. Their rising use in aquafeeds has the potential to increase price levels and volatility, worsening food insecurity among the most vulnerable populations. Although the diversification of global food production systems that includes aquaculture offers promise for enhanced resilience, such promise will not be realized if government policies fail to provide adequate incentives for resource efficiency, equity, and environmental protection.

  View details for DOI 10.1073/pnas.1404067111

  View details for Web of Science ID 000341630000022

  View details for PubMedCentralID PMC4169979

• Economic development and coastal ecosystem change in China SCIENTIFIC REPORTS He, Q., Bertness, M. D., Bruno, J. F., Li, B., Chen, G., Coverdale, T. C., Altieri, A. H., Bai, J., Sun, T., Pennings, S. C., Liu, J., Ehrlich, P. R., Cui, B. 2014; 4

  Abstract

  Despite their value, coastal ecosystems are globally threatened by anthropogenic impacts, yet how these impacts are driven by economic development is not well understood. We compiled a multifaceted dataset to quantify coastal trends and examine the role of economic growth in China's coastal degradation since the 1950s. Although China's coastal population growth did not change following the 1978 economic reforms, its coastal economy increased by orders of magnitude. All 15 coastal human impacts examined increased over time, especially after the reforms. Econometric analysis revealed positive relationships between most impacts and GDP across temporal and spatial scales, often lacking dropping thresholds. These relationships generally held when influences of population growth were addressed by analyzing per capita impacts, and when population density was included as explanatory variables. Historical trends in physical and biotic indicators showed that China's coastal ecosystems changed little or slowly between the 1950s and 1978, but have degraded at accelerated rates since 1978. Thus economic growth has been the cause of accelerating human damage to China's coastal ecosystems. China's GDP per capita remains very low. Without strict conservation efforts, continuing economic growth will further degrade China's coastal ecosystems.

  View details for DOI 10.1038/srep05995

  View details for Web of Science ID 000340593000007

  View details for PubMedID 25104138

  View details for PubMedCentralID PMC4125988

• COMMENTARY: Climate engineering reconsidered NATURE CLIMATE CHANGE Barrett, S., Lenton, T. M., Millner, A., Tavoni, A., Carpenter, S., Anderies, J. M., Chapin, F. S., Crepin, A., Daily, G., Ehrlich, P., Folke, C., Galaz, V., Hughes, T., Kautsky, N., Lambin, E. F., Naylor, R., Nyborg, K., Polasky, S., Scheffer, M., Wilen, J., Xepapadeas, A., de Zeeuw, A. 2014; 4 (7): 527-529

  View details for Web of Science ID 000338837400005

• Industries depend on biodiversity too NATURE Beattie, A. J., Ehrlich, P. R. 2014; 509 (7502): 563

  View details for PubMedID 24870533

• Countryside biogeography of Neotropical reptiles and amphibians ECOLOGY Mendenhall, C. D., Frishkoff, L. O., Santos-Barrera, G., Pacheco, J., Mesfun, E., Mendoza Quijano, F., Ehrlich, P. R., Ceballos, G., Daily, G. C., Pringle, R. M. 2014; 95 (4): 856-870

  Abstract

  The future of biodiversity and ecosystem services depends largely on the capacity of human-dominated ecosystems to support them, yet this capacity remains largely unknown. Using the framework of countryside biogeography, and working in the Las Cruces system of Coto Brus, Costa Rica, we assessed reptile and amphibian assemblages within four habitats that typify much of the Neotropics: sun coffee plantations (12 sites), pasture (12 sites), remnant forest elements (12 sites), and a larger, contiguous protected forest (3 sites in one forest). Through analysis of 1678 captures of 67 species, we draw four primary conclusions. First, we found that the majority of reptile (60%) and amphibian (70%) species in this study used an array of habitat types, including coffee plantations and actively grazed pastures. Second, we found that coffee plantations and pastures hosted rich, albeit different and less dense, reptile and amphibian biodiversity relative to the 326-ha Las Cruces Forest Reserve and neighboring forest elements. Third, we found that the small ribbons of "countryside forest elements" weaving through farmland collectively increased the effective size of a 326-ha local forest reserve 16-fold for reptiles and 14-fold for amphibians within our 236-km2 study area. Therefore, countryside forest elements, often too small for most remote sensing techniques to identify, are contributing -95% of the available habitat for forest-dependent reptiles and amphibians in our largely human-dominated study region. Fourth, we found large and pond-reproducing amphibians to prefer human-made habitats, whereas small, stream-reproducing, and directly developing species are more dependent on forest elements. Our investigation demonstrates that tropical farming landscapes can support substantial reptile and amphibian biodiversity. Our approach provides a framework for estimating the conservation value of the complex working landscapes that constitute roughly half of the global land surface, and which are experiencing intensification pressure worldwide.

  View details for DOI 10.1890/12-2017.1

  View details for Web of Science ID 000334573600007

• Introducing the Scientific Consensus on Maintaining Humanity's Life Support Systems in the 21 st Century: Information for Policy Makers ANTHROPOCENE REVIEW Barnosky, A. D., Brown, J. H., Daily, G. C., Dirzo, R., Ehrlich, A. H., Ehrlich, P. R., Eronen, J. T., Fortelius, M., Hadly, E. A., Leopold, E. B., Mooney, H. A., Myers, J., Naylor, R. L., Palumbi, S., Stenseth, N., Wake, M. H. 2014; 1 (1): 78–109

  View details for DOI 10.1177/2053019613516290

  View details for Web of Science ID 000447092100009

• Forest bolsters bird abundance, pest control and coffee yield ECOLOGY LETTERS Karp, D. S., Mendenhall, C. D., Sandi, R. F., Chaumont, N., Ehrlich, P. R., Hadly, E. A., Daily, G. C. 2013; 16 (11): 1339-1347

  Abstract

  Efforts to maximise crop yields are fuelling agricultural intensification, exacerbating the biodiversity crisis. Low-intensity agricultural practices, however, may not sacrifice yields if they support biodiversity-driven ecosystem services. We quantified the value native predators provide to farmers by consuming coffee's most damaging insect pest, the coffee berry borer beetle (Hypothenemus hampei). Our experiments in Costa Rica showed birds reduced infestation by ~ 50%, bats played a marginal role, and farmland forest cover increased pest removal. We identified borer-consuming bird species by assaying faeces for borer DNA and found higher borer-predator abundances on more forested plantations. Our coarse estimate is that forest patches doubled pest control over 230 km2 by providing habitat for ~ 55 000 borer-consuming birds. These pest-control services prevented US$75-US$310 ha-year(-1) in damage, a benefit per plantation on par with the average annual income of a Costa Rican citizen. Retaining forest and accounting for pest control demonstrates a win-win for biodiversity and coffee farmers.

  View details for DOI 10.1111/ele.12173

  View details for Web of Science ID 000325976500002

  View details for PubMedID 23981013

• Future collapse: how optimistic should we be? Proceedings. Biological sciences / The Royal Society Ehrlich, P. R., Ehrlich, A. H. 2013; 280 (1767): 20131373-?

  View details for DOI 10.1098/rspb.2013.1373

  View details for PubMedID 23902905

  View details for PubMedCentralID PMC3735257

• Pervasive Externalities at the Population, Consumption, and Environment Nexus SCIENCE Dasgupta, P. S., Ehrlich, P. R. 2013; 340 (6130): 324-328

  Abstract

  Growing concerns that contemporary patterns of economic development are unsustainable have given rise to an extensive empirical literature on population growth, consumption increases, and our growing use of nature's products and services. However, far less has been done to reach a theoretical understanding of the socio-ecological processes at work at the population-consumption-environment nexus. In this Research Article, we highlight the ubiquity of externalities (which are the unaccounted for consequences for others, including future people) of decisions made by each of us on reproduction, consumption, and the use of our natural environment. Externalities, of which the "tragedy of the commons" remains the most widely discussed illustration, are a cause of inefficiency in the allocation of resources across space, time, and contingencies; in many situations, externalities accentuate inequity as well. Here, we identify and classify externalities in consumption and reproductive decisions and use of the natural environment so as to construct a unified theoretical framework for the study of data drawn from the nexus. We show that externalities at the nexus are not self-correcting in the marketplace. We also show that fundamental nonlinearities, built into several categories of externalities, amplify the socio-ecological processes operating at the nexus. Eliminating the externalities would, therefore, require urgent collective action at both local and global levels.

  View details for DOI 10.1126/science.1224664

  View details for Web of Science ID 000317657500047

  View details for PubMedID 23599486

• Social-ecological systems as complex adaptive systems: modeling and policy implications ENVIRONMENT AND DEVELOPMENT ECONOMICS Levin, S., Xepapadeas, T., Crepin, A., Norberg, J., De Zeeuw, A., Folke, C., Hughes, T., Arrow, K., Barrett, S., Daily, G., Ehrlich, P., Kautsky, N., Maler, K., Polasky, S., Troell, M., Vincent, J. R., Walker, B. 2013; 18: 111-132

  View details for DOI 10.1017/S1355770X12000460

  View details for Web of Science ID 000316190400001

• Can a collapse of global civilization be avoided? PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES Ehrlich, P. R., Ehrlich, A. H. 2013; 280 (1754)

  Abstract

  Environmental problems have contributed to numerous collapses of civilizations in the past. Now, for the first time, a global collapse appears likely. Overpopulation, overconsumption by the rich and poor choices of technologies are major drivers; dramatic cultural change provides the main hope of averting calamity.

  View details for DOI 10.1098/rspb.2012.2845

  View details for Web of Science ID 000313663700017

  View details for PubMedID 23303549

  View details for PubMedCentralID PMC3574335

• Social Norms and Global Environmental Challenges: The Complex Interaction of Behaviors, Values, and Policy BIOSCIENCE Kinzig, A. P., Ehrlich, P. R., Alston, L. J., Arrow, K., Barrett, S., Buchman, T. G., Daily, G. C., Levin, B., Levin, S., Oppenheimer, M., Ostrom, E., Saari, D. 2013; 63 (3): 164-175

  Abstract

  Government policies are needed when people's behaviors fail to deliver the public good. Those policies will be most effective if they can stimulate long-term changes in beliefs and norms, creating and reinforcing the behaviors needed to solidify and extend the public good.It is often the short-term acceptability of potential policies, rather than their longer-term efficacy, that determines their scope and deployment. The policy process should consider both time scales. The academy, however, has provided insufficient insight on the coevolution of social norms and different policy instruments, thus compromising the capacity of decision makers to craft effective solutions to the society's most intractable environmental problems. Life scientists could make fundamental contributions to this agenda through targeted research on the emergence of social norms.

  View details for DOI 10.1525/bio.2013.63.3.5

  View details for Web of Science ID 000322048200005

  View details for PubMedCentralID PMC4136381

• Social Norms and Global Environmental Challenges: The Complex Interaction of Behaviors, Values, and Policy. Bioscience Kinzig, A. P., Ehrlich, P. R., Alston, L. J., Arrow, K., Barrett, S., Buchman, T. G., Daily, G. C., Levin, B., Levin, S., Oppenheimer, M., Ostrom, E., Saari, D. 2013; 63 (3): 164-175

  Abstract

  Government policies are needed when people's behaviors fail to deliver the public good. Those policies will be most effective if they can stimulate long-term changes in beliefs and norms, creating and reinforcing the behaviors needed to solidify and extend the public good.It is often the short-term acceptability of potential policies, rather than their longer-term efficacy, that determines their scope and deployment. The policy process should consider both time scales. The academy, however, has provided insufficient insight on the coevolution of social norms and different policy instruments, thus compromising the capacity of decision makers to craft effective solutions to the society's most intractable environmental problems. Life scientists could make fundamental contributions to this agenda through targeted research on the emergence of social norms.

  View details for DOI 10.1525/bio.2013.63.3.5

  View details for PubMedID 25143635

  View details for PubMedCentralID PMC4136381

• The decoupling of human and natural systems makes me very grumpy Annual Forum on Grumpy Scientists: the Ecological Conscience of a Nation Ehrlich, P. R. ROYAL ZOOLOGICAL SOC NEW SOUTH WALES. 2013: 9–13

  View details for DOI 10.7882/FS.2013.005

  View details for Web of Science ID 000339033000004

• Human Dependence on Nature How to help solve the environmental crisis Foreword HUMAN DEPENDENCE ON NATURE: HOW TO HELP SOLVE THE ENVIRONMENTAL CRISIS Ehrlich, P. R., Washington, H. 2013: XV-XVI

  View details for Web of Science ID 000331135100001

• Energy is life HUMAN DEPENDENCE ON NATURE: HOW TO HELP SOLVE THE ENVIRONMENTAL CRISIS Ehrlich, P. R., Washington, H. 2013: 5–14

  View details for Web of Science ID 000331135100003

• The great cycles HUMAN DEPENDENCE ON NATURE: HOW TO HELP SOLVE THE ENVIRONMENTAL CRISIS Ehrlich, P. R., Washington, H. 2013: 15–26

  View details for Web of Science ID 000331135100004

• Ecosystem services - essential but overlooked HUMAN DEPENDENCE ON NATURE: HOW TO HELP SOLVE THE ENVIRONMENTAL CRISIS Ehrlich, P. R., Washington, H. 2013: 27–41

  View details for Web of Science ID 000331135100005

• Collapse HUMAN DEPENDENCE ON NATURE: HOW TO HELP SOLVE THE ENVIRONMENTAL CRISIS Ehrlich, P. R., Washington, H. 2013: 43–54

  View details for Web of Science ID 000331135100006

• Psychological, cultural and spiritual dependence on Nature HUMAN DEPENDENCE ON NATURE: HOW TO HELP SOLVE THE ENVIRONMENTAL CRISIS Ehrlich, P. R., Washington, H. 2013: 55–65

  View details for Web of Science ID 000331135100007

• The great divide - anthropocentrism vs ecocentrism HUMAN DEPENDENCE ON NATURE: HOW TO HELP SOLVE THE ENVIRONMENTAL CRISIS Ehrlich, P. R., Washington, H. 2013: 67–81

  View details for Web of Science ID 000331135100008

• Dealing with denial HUMAN DEPENDENCE ON NATURE: HOW TO HELP SOLVE THE ENVIRONMENTAL CRISIS Ehrlich, P. R., Washington, H. 2013: 83–97

  View details for Web of Science ID 000331135100009

• Do we have a problem? HUMAN DEPENDENCE ON NATURE: HOW TO HELP SOLVE THE ENVIRONMENTAL CRISIS Ehrlich, P. R., Washington, H. 2013: 99–110

  View details for Web of Science ID 000331135100010

• Solutions to keep our roots in the Earth HUMAN DEPENDENCE ON NATURE: HOW TO HELP SOLVE THE ENVIRONMENTAL CRISIS Ehrlich, P. R., Washington, H. 2013: 111–39

  View details for Web of Science ID 000331135100011

• Human Dependence on Nature How to help solve the environmental crisis Introduction HUMAN DEPENDENCE ON NATURE: HOW TO HELP SOLVE THE ENVIRONMENTAL CRISIS Ehrlich, P. R., Washington, H. 2013: 1-+

  View details for Web of Science ID 000331135100002

• Capitalism Versus the Environment OCCUPY THE FUTURE Ehrlich, P. R., Ehrlich, A. H., Grusky, D. B., McAdam, D., Reich, R., Satz, D. 2013: 183–93

  View details for Web of Science ID 000318227200013

• Intensive agriculture erodes beta-diversity at large scales ECOLOGY LETTERS Karp, D. S., Rominger, A. J., Zook, J., Ranganathan, J., Ehrlich, P. R., Daily, G. C. 2012; 15 (9): 963-970

  Abstract

  Biodiversity is declining from unprecedented land conversions that replace diverse, low-intensity agriculture with vast expanses under homogeneous, intensive production. Despite documented losses of species richness, consequences for β-diversity, changes in community composition between sites, are largely unknown, especially in the tropics. Using a 10-year data set on Costa Rican birds, we find that low-intensity agriculture sustained β-diversity across large scales on a par with forest. In high-intensity agriculture, low local (α) diversity inflated β-diversity as a statistical artefact. Therefore, at small spatial scales, intensive agriculture appeared to retain β-diversity. Unlike in forest or low-intensity systems, however, high-intensity agriculture also homogenised vegetation structure over large distances, thereby decoupling the fundamental ecological pattern of bird communities changing with geographical distance. This ~40% decline in species turnover indicates a significant decline in β-diversity at large spatial scales. These findings point the way towards multi-functional agricultural systems that maintain agricultural productivity while simultaneously conserving biodiversity.

  View details for DOI 10.1111/j.1461-0248.2012.01815.x

  View details for Web of Science ID 000306475600005

  View details for PubMedID 22727063

• Improving estimates of biodiversity loss BIOLOGICAL CONSERVATION Mendenhall, C. D., Daily, G. C., Ehrlich, P. R. 2012; 151 (1): 32-34

  View details for DOI 10.1016/j.biocon.2012.01.069

  View details for Web of Science ID 000306042600008

• Securing natural capital and expanding equity to rescale civilization NATURE Ehrlich, P. R., Kareiva, P. M., Daily, G. C. 2012; 486 (7401): 68-73

  Abstract

  In biophysical terms, humanity has never been moving faster nor further from sustainability than it is now. Our increasing population size and per capita impacts are severely testing the ability of Earth to provide for peoples' most basic needs. Awareness of these circumstances has grown tremendously, as has the sophistication of efforts to address them. But the complexity of the challenge remains daunting. We explore prospects for transformative change in three critical areas of sustainable development: achieving a sustainable population size and securing vital natural capital, both in part through reducing inequity, and strengthening the societal leadership of academia.

  View details for DOI 10.1038/nature11157

  View details for Web of Science ID 000304854000028

  View details for PubMedID 22678281

• Human behavior and sustainability FRONTIERS IN ECOLOGY AND THE ENVIRONMENT Fischer, J., Dyball, R., Fazey, I., Gross, C., Dovers, S., Ehrlich, P. R., Brulle, R. J., Christensen, C., Borden, R. J. 2012; 10 (3): 153-160

  View details for DOI 10.1890/110079

  View details for Web of Science ID 000302441000020

• Reply to Wiersma and Nudds: Despite constraints, our approach still best available PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Pompa, S., Ehrlich, P. R., Ceballos, G. 2012; 109 (6): E289

  View details for DOI 10.1073/pnas.1119266109

  View details for Web of Science ID 000299925000002

• Reservoirs of richness: least disturbed tropical forests are centres of undescribed species diversity PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES Giam, X., Scheffers, B. R., Sodhi, N. S., Wilcove, D. S., Ceballos, G., Ehrlich, P. R. 2012; 279 (1726): 67-76

  Abstract

  In the last few decades, there has been a remarkable discovery of new species of plants, invertebrates and vertebrates, in what have been called the new age of discovery. However, owing to anthropogenic impacts such as habitat conversion, many of the still unknown species may go extinct before being scientifically documented (i.e. 'crypto-extinctions'). Here, by applying a mathematical model of species descriptions which accounts for taxonomic effort, we show that even after 250 years of taxonomic classification, about 3050 amphibians and at least 160 land mammal species remain to be discovered and described. These values represent, respectively, 33 and 3 per cent of the current species total for amphibians and land mammals. We found that tropical moist forests of the Neotropics, Afrotropics and Indomalaya probably harbour the greatest numbers of undescribed species. Tropical forests with minimal anthropogenic disturbance are predicted to have larger proportions of undescribed species. However, the protected area coverage is low in many of these key biomes. Moreover, undescribed species are likely to be at a greater risk of extinction compared with known species because of small geographical ranges among other factors. By highlighting the key areas of undescribed species diversity, our study provides a starting template to rapidly document these species and protect them through better habitat management.

  View details for DOI 10.1098/rspb.2011.0433

  View details for Web of Science ID 000297674300010

  View details for PubMedID 21593037

  View details for PubMedCentralID PMC3223638

• Resilience and stability in bird guilds across tropical countryside PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Karp, D. S., Ziv, G., Zook, J., Ehrlich, P. R., Daily, G. C. 2011; 108 (52): 21134-21139

  Abstract

  The consequences of biodiversity decline in intensified agricultural landscapes hinge on surviving biotic assemblages. Maintaining crucial ecosystem processes and services requires resilience to natural and anthropogenic disturbances. However, the resilience and stability of surviving biological communities remain poorly quantified. From a 10-y dataset comprising 2,880 bird censuses across a land-use gradient, we present three key findings concerning the resilience and stability of Costa Rican bird communities. First, seed dispersing, insect eating, and pollinating guilds were more resilient to low-intensity land use than high-intensity land use. Compared with forest assemblages, bird abundance, species richness, and diversity were all ~15% lower in low-intensity land use and ~50% lower in high-intensity land use. Second, patterns in species richness generally correlated with patterns in stability: guilds exhibited less variation in abundance in low-intensity land use than in high-intensity land use. Finally, interspecific differences in reaction to environmental change (response diversity) and possibly the portfolio effect, but not negative covariance of species abundances, conferred resilience and stability. These findings point to the changes needed in agricultural production practices in the tropics to better sustain bird communities and, possibly, the functional and service roles that they play.

  View details for DOI 10.1073/pnas.1118276108

  View details for Web of Science ID 000298479900055

  View details for PubMedID 22160726

  View details for PubMedCentralID PMC3248489

• Homage to an Avant-Garde Conservation Leader, Navjot Sodhi Obituary CONSERVATION BIOLOGY Bradshaw, C. J., Laurance, W. F., Gibson, L., Ehrlich, P. R., Brook, B. W. 2011; 25 (5): 1056-1058

  View details for DOI 10.1111/j.1523-1739.2011.01730.x

  View details for Web of Science ID 000294908000024

  View details for PubMedID 21790787

• Predictive model for sustaining biodiversity in tropical countryside PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Mendenhall, C. D., Sekercioglu, C. H., Brenes, F. O., Ehrlich, P. R., Daily, G. C. 2011; 108 (39): 16313-16316

  Abstract

  Growing demand for food, fuel, and fiber is driving the intensification and expansion of agricultural land through a corresponding displacement of native woodland, savanna, and shrubland. In the wake of this displacement, it is clear that farmland can support biodiversity through preservation of important ecosystem elements at a fine scale. However, how much biodiversity can be sustained and with what tradeoffs for production are open questions. Using a well-studied tropical ecosystem in Costa Rica, we develop an empirically based model for quantifying the "wildlife-friendliness" of farmland for native birds. Some 80% of the 166 mist-netted species depend on fine-scale countryside forest elements (≤ 60-m-wide clusters of trees, typically of variable length and width) that weave through farmland along hilltops, valleys, rivers, roads, and property borders. Our model predicts with ∼75% accuracy the bird community composition of any part of the landscape. We find conservation value in small (≤ 20 m wide) clusters of trees and somewhat larger (≤ 60 m wide) forest remnants to provide substantial support for biodiversity beyond the borders of tropical forest reserves. Within the study area, forest elements on farms nearly double the effective size of the local forest reserve, providing seminatural habitats for bird species typically associated with the forest. Our findings provide a basis for estimating and sustaining biodiversity in farming systems through managing fine-scale ecosystem elements and, more broadly, informing ecosystem service analyses, biodiversity action plans, and regional land use strategies.

  View details for DOI 10.1073/pnas.1111687108

  View details for Web of Science ID 000295255300040

  View details for PubMedID 21911396

  View details for PubMedCentralID PMC3182680

• Global distribution and conservation of marine mammals PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Pompa, S., Ehrlich, P. R., Ceballos, G. 2011; 108 (33): 13600-13605

  Abstract

  We identified 20 global key conservation sites for all marine (123) and freshwater (6) mammal species based on their geographic ranges. We created geographic range maps for all 129 species and a Geographic Information System database for a 46,184 1° x 1° grid-cells, ∼10,000-km(2). Patterns of species richness, endemism, and risk were variable among all species and species groups. Interestingly, marine mammal species richness was correlated strongly with areas of human impact across the oceans. Key conservation sites in the global geographic grid were determined either by their species richness or by their irreplaceability or uniqueness, because of the presence of endemic species. Nine key conservation sites, comprising the 2.5% of the grid cells with the highest species richness, were found, mostly in temperate latitudes, and hold 84% of marine mammal species. In addition, we identified 11 irreplaceable key conservation sites, six of which were found in freshwater bodies and five in marine regions. These key conservation sites represent critical areas of conservation value at a global level and can serve as a first step for adopting global strategies with explicit geographic conservation targets for Marine Protected Areas.

  View details for DOI 10.1073/pnas.1101525108

  View details for Web of Science ID 000293895100051

  View details for PubMedID 21808012

  View details for PubMedCentralID PMC3158205

• Non-natives: 141 scientists object NATURE Simberloff, D., Alexander, J., Allendorf, F., Aronson, J., Antunes, P. M., Bacher, S., Bardgett, R., Bertolino, S., Bishop, M., Blackburn, T. M., Blakeslee, A., Blumenthal, D., Bortolus, A., Buckley, R., Buckley, Y., Byers, J., Callaway, R. M., Campbell, F., Campbell, K., Campbell, M., Carlton, J. T., Cassey, P., Catford, J., Celesti-Grapow, L., Chapman, J., Clark, P., Clewell, A., Clode, J. C., Chang, A., Chytry, M., Clout, M., Cohen, A., Cowan, P., Cowie, R. H., Crall, A. W., Crooks, J., Deveney, M., Dixon, K., Dobbs, F. C., Duffy, D. C., Duncan, R., Ehrlich, P. R., Eldredge, L., Evenhuis, N., Fausch, K. D., Feldhaar, H., Firn, J., Fowler, A., Galil, B., Garcia-Berthou, E., Geller, J., Genovesi, P., Gerber, E., Gherardi, F., Gollasch, S., Gordon, D., Graham, J., Gribben, P., Griffen, B., Grosholz, E. D., Hewitt, C., Hierro, J. L., Hulme, P., Hutchings, P., Jarosik, V., Jeschke, J. M., Johnson, C., Johnson, L., Johnston, E. L., Jones, C. G., Keller, R., King, C. M., Knols, B. G., Kollmann, J., Kompas, T., Kotanen, P. M., Kowarik, I., Kuehn, I., Kumschick, S., Leung, B., Liebhold, A., MacIsaac, H., Mack, R., Mccullough, D. G., McDonald, R., Merritt, D. M., Meyerson, L., Minchin, D., Mooney, H. A., Morisette, J. T., Moyle, P., Heinz, M., Murray, B. R., Nehring, S., Nelson, W., Nentwig, W., Novak, S. J., Occhipinti, A., Ojaveer, H., Osborne, B., Ostfeld, R. S., Parker, J., Pederson, J., Pergl, J., Phillips, M. L., Pysek, P., Rejmanek, M., Ricciardi, A., Ricotta, C., Richardson, D., Rilov, G., Ritchie, E., Robertson, P. A., Roman, J., Ruiz, G., Schaefer, H., Schaffelke, B., Schierenbeck, K. A., Schmitz, D. C., Schwindt, E., Seeb, J., Smith, L. D., Smith, G. F., Stohlgren, T., Strayer, D. L., Strong, D., Sutherland, W. J., Therriault, T., Thuiller, W., Torchin, M., van der Putten, W. H., Vila, M., Von Holle, B., Wallentinus, I., Wardle, D., Williamson, M., Wilson, J., Winter, M., Wolfe, L. M., Wright, J., Wonham, M., Zabin, C. 2011; 475 (7354): 36-36

  View details for Web of Science ID 000292461300028

• Intervention Ecology: Applying Ecological Science in the Twenty-first Century BIOSCIENCE Hobbs, R. J., Hallett, L. M., Ehrlich, P. R., Mooney, H. A. 2011; 61 (6): 442-450

  View details for DOI 10.1525/bio.2011.61.6.6

  View details for Web of Science ID 000291333700006

• Population decline assessment, historical baselines, and conservation CONSERVATION LETTERS Bonebrake, T. C., Christensen, J., Boggs, C. L., Ehrlich, P. R. 2010; 3 (6): 371-378

  View details for DOI 10.1111/j.1755-263X.2010.00139.x

  View details for Web of Science ID 000284893700001

• Still Ticking SCIENTIST Ehrlich, P., Ticking, S. 2010; 24 (12): 26-+

  View details for Web of Science ID 000284791300004

• Setting the record straight (again) NATURE Mann, M. E., Ehrlich, P. R., Rahmstorf, S. 2010; 467 (7318): 920-920

  View details for Web of Science ID 000283254700020

• A Pivotal Moment: Population, Justice and The Environmental Challenge. (Book Review) ECOLOGICAL ECONOMICS Book Review Authored by: Ehrlich, A. H., Ehrlich, P. R. 2010; 69 (12): 2647–49

  View details for DOI 10.1016/j.ecolecon.2010.07.018

  View details for Web of Science ID 000283700900041

• Retrospective. Stephen Schneider (1945-2010). Science Ehrlich, P. R. 2010; 329 (5993): 776-?

  View details for DOI 10.1126/science.1195502

  View details for PubMedID 20705843

• More than just indicators: A review of tropical butterfly ecology and conservation BIOLOGICAL CONSERVATION Bonebrake, T. C., Ponisio, L. C., Boggs, C. L., Ehrlich, P. R. 2010; 143 (8): 1831-1841

  View details for DOI 10.1016/j.biocon.2010.04.044

  View details for Web of Science ID 000279500800003

• Oviposition behavior and offspring performance in herbivorous insects: consequences of climatic and habitat heterogeneity OIKOS Bonebrake, T. C., Boggs, C. L., McNally, J. M., Ranganathan, J., Ehrlich, P. R. 2010; 119 (6): 927-934

  View details for DOI 10.1111/j.1600-0706.2009.17759.x

  View details for Web of Science ID 000278036500004

• Biological collections and ecological/environmental research: a review, some observations and a look to the future BIOLOGICAL REVIEWS Pyke, G. H., Ehrlich, P. R. 2010; 85 (2): 247-266

  Abstract

  Housed worldwide, mostly in museums and herbaria, is a vast collection of biological specimens developed over centuries. These biological collections, and associated taxonomic and systematic research, have received considerable long-term public support. The work remaining in systematics has been expanding as the estimated total number of species of organisms on Earth has risen over recent decades, as have estimated numbers of undescribed species. Despite this increasing task, support for taxonomic and systematic research, and biological collections upon which such research is based, has declined over the last 30-40 years, while other areas of biological research have grown considerably, especially those that focus on environmental issues. Reflecting increases in research that deals with ecological questions (e.g. what determines species distribution and abundance) or environmental issues (e.g. toxic pollution), the level of research attempting to use biological collections in museums or herbaria in an ecological/environmental context has risen dramatically during about the last 20 years. The perceived relevance of biological collections, and hence the support they receive, should be enhanced if this trend continues and they are used prominently regarding such environmental issues as anthropogenic loss of biodiversity and associated ecosystem function, global climate change, and decay of the epidemiological environment. It is unclear, however, how best to use biological collections in the context of such ecological/environmental issues or how best to manage collections to facilitate such use. We demonstrate considerable and increasingly realized potential for research based on biological collections to contribute to ecological/environmental understanding. However, because biological collections were not originally intended for use regarding such issues and have inherent biases and limitations, they are proving more useful in some contexts than in others. Biological collections have, for example, been particularly useful as sources of information regarding variation in attributes of individuals (e.g. morphology, chemical composition) in relation to environmental variables, and provided important information in relation to species' distributions, but less useful in the contexts of habitat associations and population sizes. Changes to policies, strategies and procedures associated with biological collections could mitigate these biases and limitations, and hence make such collections more useful in the context of ecological/environmental issues. Haphazard and opportunistic collecting could be replaced with strategies for adding to existing collections that prioritize projects that use biological collections and include, besides taxonomy and systematics, a focus on significant environmental/ecological issues. Other potential changes include increased recording of the nature and extent of collecting effort and information associated with each specimen such as nearby habitat and other individuals observed but not collected. Such changes have begun to occur within some institutions. Institutions that house biological collections should, we think, pursue a mission of 'understanding the life of the planet to inform its stewardship' (Krishtalka & Humphrey, 2000), as such a mission would facilitate increased use of biological collections in an ecological/environmental context and hence lead to increased appreciation, encouragement and support from the public for these collections, their associated research, and the institutions that house them.

  View details for DOI 10.1111/j.1469-185X.2009.00098.x

  View details for Web of Science ID 000276602200003

  View details for PubMedID 19961469

• The Missing Link in Biodiversity Conservation SCIENCE Beattie, A., Ehrlich, P. 2010; 328 (5976): 307–8

  View details for DOI 10.1126/science.328.5976.307-c

  View details for Web of Science ID 000276685000015

  View details for PubMedID 20395493

• The MAHB, the Culture Gap, and Some Really Inconvenient Truths PLOS BIOLOGY Ehrlich, P. R. 2010; 8 (4)

  View details for DOI 10.1371/journal.pbio.1000330

  View details for PubMedID 20386722

• Local people value environmental services provided by forested parks BIODIVERSITY AND CONSERVATION Sodhi, N. S., Lee, T. M., Sekercioglu, C. H., Webb, E. L., Prawiradilaga, D. M., Lohman, D. J., Pierce, N. E., Diesmos, A. C., Rao, M., Ehrlich, P. R. 2010; 19 (4): 1175-1188

  View details for DOI 10.1007/s10531-009-9745-9

  View details for Web of Science ID 000275536700017

• The MAHB and the BioScience Gang BIOSCIENCE Ehrlich, P. R. 2010; 60 (3): 170–71

  View details for DOI 10.1525/bio.2010.60.3.2

  View details for Web of Science ID 000275729900002

• Conservation Biology for All Introduction CONSERVATION BIOLOGY FOR ALL Sodhi, N. S., Ehrlich, P. R., Sodhi, N. S., Ehrlich, P. R. 2010: 1–6

  View details for Web of Science ID 000355184200001

• Ecoethics: Now Central to All Ethics JOURNAL OF BIOETHICAL INQUIRY Ehrlich, P. R. 2009; 6 (4): 417-436

  View details for DOI 10.1007/s11673-009-9197-7

  View details for Web of Science ID 000272176300003

• Inferring population histories using cultural data PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES Rogers, D. S., Feldman, M. W., Ehrlich, P. R. 2009; 276 (1674): 3835-3843

  Abstract

  The question as to whether cultures evolve in a manner analogous to that of genetic evolution can be addressed by attempting to reconstruct population histories using cultural data. As others have argued, this can only succeed if cultures are isolated enough to maintain and pass on a central core of traditions that can be modified over time. In this study we used a set of cultural data (canoe design traits from Polynesia) to look for the kinds of patterns and relationships normally found in population genetic studies. After developing new techniques to accommodate the peculiarities of cultural data, we were able to infer an ancestral region (Fiji) and a sequence of cultural origins for these Polynesian societies. In addition, we found evidence of cultural exchange, migration and a serial founder effect. Results were stronger when analyses were based on functional traits (presumably subject to natural selection and convergence) rather than symbolic or stylistic traits (probably subject to cultural selection for rapid divergence). These patterns strongly suggest that cultural evolution, while clearly affected by cultural exchange, is also subject to some of the same processes and constraints as genetic evolution.

  View details for DOI 10.1098/rspb.2009.1088

  View details for Web of Science ID 000270174800013

  View details for PubMedID 19675007

  View details for PubMedCentralID PMC2817289

• 7 billon and counting ... NEW SCIENTIST Ehrlich, P., Ehrlich, A. 2009; 203 (2727): 34-37

  View details for Web of Science ID 000270335300036

• Big thinkers, big ideas NEW SCIENTIST Musk, E., Ehrlich, P. R., Rees, M. 2009; 203 (2726): 33

  View details for Web of Science ID 000270266100031

• Looming Global-Scale Failures and Missing Institutions SCIENCE Walker, B., Barrett, S., Polasky, S., Galaz, V., Folke, C., Engstrom, G., Ackerman, F., Arrow, K., Carpenter, S., Chopra, K., Daily, G., Ehrlich, P., Hughes, T., Kautsky, N., Levin, S., Maler, K., Shogren, J., Vincent, J., Xepapadeas, T., de Zeeuw, A. 2009; 325 (5946): 1345-1346

  View details for DOI 10.1126/science.1175325

  View details for Web of Science ID 000269699100020

• Cultural evolution and the human predicament TRENDS IN ECOLOGY & EVOLUTION Ehrlich, P. R. 2009; 24 (8): 409-412

  Abstract

  For decades, scientists have been calling for action to halt environmental degradation, and there has been a substantial (but variable) response from the ecological and evolutionary research communities. Nonetheless, the degradation continues more rapidly than ever, by almost any biophysical measure. Here I briefly summarize and frame the situation, and suggest some major research thrusts for our community to accelerate the needed cultural responses, given that accumulating human impacts could threaten the collapse of global civilization.

  View details for DOI 10.1016/j.tree.2009.03.015

  View details for Web of Science ID 000269051400001

  View details for PubMedID 19577322

• Fostering constructive debate: a reply to Chappell et al. FRONTIERS IN ECOLOGY AND THE ENVIRONMENT Fischer, J., Brosi, B., Daily, G. C., Ehrlich, P. R., Goldman, R., Goldstein, J., Lindenmayer, D. B., Manning, A. D., Mooney, H. A., Pejchar, L., Ranganathan, J., Tallis, H. 2009; 7 (4): 84

  View details for DOI 10.1890/09.WB.012

  View details for Web of Science ID 000265971200016

• Agricultural landscapes remain an essential front for biodiversity conservation Reply PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Ranganathan, J., Daniels, R., Chandran, M., Ehrlich, P. R., Daily, G. C. 2009; 106 (14): E35

  View details for DOI 10.1073/pnas.0901856106

  View details for Web of Science ID 000264967500106

• Discoveries of new mammal species and their implications for conservation and ecosystem services PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Ceballos, G., Ehrlich, P. R. 2009; 106 (10): 3841-3846

  Abstract

  In light of recent discoveries of many new species of poorly-studied organisms, we examine the biodiversity of mammals, a well known "charismatic" group. Many assume that nearly all mammal species are known to scientists. We demonstrate that this assumption is incorrect. Since 1993, 408 new mammalian species have been described, approximately 10% of the previously known fauna. Some 60% of these are "cryptic" species, but 40% are large and distinctive. A substantial number persist only in areas undergoing rapid habitat destruction. Our findings suggest global animal and plant species diversity is badly underestimated even in well studied taxa. This implies even greater threats to ecosystem services and human well-being than previously assumed, and an increased need to explore, understand, and conserve Earth's living resources.

  View details for DOI 10.1073/pnas.0812419106

  View details for Web of Science ID 000264036900037

  View details for PubMedID 19228946

  View details for PubMedCentralID PMC2656167

• Diversity in Current Ecological Thinking: Implications for Environmental Management ENVIRONMENTAL MANAGEMENT Moore, S. A., Wallington, T. J., Hobbs, R. J., Ehrlich, P. R., Holling, C. S., Levin, S., Lindenmayer, D., Pahl-Wostl, C., Possingham, H., Turner, M. G., Westoby, M. 2009; 43 (1): 17-27

  Abstract

  Current ecological thinking emphasizes that systems are complex, dynamic, and unpredictable across space and time. What is the diversity in interpretation of these ideas among today's ecologists, and what does this mean for environmental management? This study used a Policy Delphi survey of ecologists to explore their perspectives on a number of current topics in ecology. The results showed general concurrence with nonequilibrium views. There was agreement that disturbance is a widespread, normal feature of ecosystems with historically contingent responses. The importance of recognizing multiple levels of organization and the role of functional diversity in environmental change were also widely acknowledged. Views differed regarding the predictability of successional development, whether "patchiness" is a useful concept, and the benefits of shifting the focus from species to ecosystem processes. Because of their centrality to environmental management, these different views warrant special attention from both managers and ecologists. Such divergence is particularly problematic given widespread concerns regarding the poor linkages between science (here, ecology) and environmental policy and management, which have been attributed to scientific uncertainty and a lack of consensus among scientists, both jeopardizing the transfer of science into management. Several suggestions to help managers deal with these differences are provided, especially the need to interpret broader theory in the context of place-based assessments. The uncertainty created by these differences requires a proactive approach to environmental management, including clearly identifying environmental objectives, careful experimental design, and effective monitoring.

  View details for DOI 10.1007/s00267-008-9187-2

  View details for Web of Science ID 000261762900002

  View details for PubMedID 18709471

• Sustaining biodiversity in ancient tropical countryside PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Ranganathan, J., Daniels, R. J., Chandran, M. D., Ehrlich, P. R., Daily, G. C. 2008; 105 (46): 17852-17854

  Abstract

  With intensifying demands for food and biofuels, a critical threat to biodiversity is agricultural expansion into native tropical ecosystems. Tropical agriculture, particularly intensive agriculture, often supports few native organisms, and consequently has been largely overlooked in conservation planning; yet, recent work in the Neotropics demonstrates that tropical agriculture with certain features can support significant biodiversity, decades after conversion to farmland. It remains unknown whether this conservation value can be sustained for centuries to millennia. Here, we quantify the bird diversity affiliated with agricultural systems in southwest India, a region continuously cultivated for >2,000 years. We show that arecanut palm (Areca catechu) production systems retain 90% of the bird species associated with regional native forest. Two factors promote this high conservation value. First, the system involves intercropping with multiple, usually woody, understory species and, thus, has high vertical structural complexity that is positively correlated with bird species richness. Second, the system encompasses nearby forests, where large quantities of leaf litter are extracted for mulch. The preservation of these forests on productive land traces back to their value in supplying inputs to arecanut cultivation. The long-term biodiversity value of an agricultural ecosystem has not been documented in South and Southeast Asia. Our findings open a new conservation opportunity for this imperiled region that may well extend to other crops. Some of these working lands may be able to sustain native species over long-time scales, indicating that conservation investments in agriculture today could pay off for people and for nature.

  View details for DOI 10.1073/pnas.0808874105

  View details for Web of Science ID 000261225600052

  View details for PubMedID 18981411

  View details for PubMedCentralID PMC2577706

• Should agricultural policies encourage land sparing or wildlife-friendly farming? FRONTIERS IN ECOLOGY AND THE ENVIRONMENT Fischer, J., Brosi, B., Daily, G. C., Ehrlich, P. R., Goldman, R., Goldstein, J., Lindenmayer, D. B., Manning, A. D., Mooney, H. A., Pejchar, L., Ranganathan, J., Tallis, H. 2008; 6 (7): 382-387

  View details for DOI 10.1890/070019

  View details for Web of Science ID 000259308000020

• Colloquium paper: where does biodiversity go from here? A grim business-as-usual forecast and a hopeful portfolio of partial solutions. Proceedings of the National Academy of Sciences of the United States of America Ehrlich, P. R., Pringle, R. M. 2008; 105: 11579-11586

  Abstract

  The threats to the future of biodiversity are many and well known. They include habitat conversion, environmental toxification, climate change, and direct exploitation of wildlife, among others. Moreover, the projected addition of 2.6 billion people by mid-century will almost certainly have a greater environmental impact than that of the last 2.6 billion. Collectively, these trends portend a grim future for biodiversity under a business-as-usual scenario. These threats and their interactions are formidable, but we review seven strategies that, if implemented soundly and scaled up dramatically, would preserve a substantial portion of global biodiversity. These are actions to stabilize the human population and reduce its material consumption, the deployment of endowment funds and other strategies to ensure the efficacy and permanence of conservation areas, steps to make human-dominated landscapes hospitable to biodiversity, measures to account for the economic costs of habitat degradation, the ecological reclamation of degraded lands and repatriation of extirpated species, the education and empowerment of people in the rural tropics, and the fundamental transformation of human attitudes about nature. Like the carbon "stabilization wedges" outlined by Pacala and Socolow [Pacala S, Socolow R (2004) Stabilization wedges: Solving the climate problem for the next 50 years with current technologies. Science 305:968-972] (1), the science and technologies needed to effect this vision already exist. The remaining challenges are largely social, political, and economic. Although academic conservation biology still has an important role to play in developing technical tools and knowledge, success at this juncture hinges more on a massive mobilization of effort to do things that have traditionally been outside the scope of the discipline.

  View details for DOI 10.1073/pnas.0801911105

  View details for PubMedID 18695214

  View details for PubMedCentralID PMC2556413

• Cost-effective priorities for global mammal conservation PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Carwardine, J., Wilson, K. A., Ceballos, G., Ehrlich, P. R., Naidoo, R., Iwamura, T., Hajkowicz, S. A., Possingham, H. P. 2008; 105 (32): 11446-11450

  Abstract

  Global biodiversity priority setting underpins the strategic allocation of conservation funds. In identifying the first comprehensive set of global priority areas for mammals, Ceballos et al. [Ceballos G, Ehrlich PR, Soberón J, Salazar I, Fay JP (2005) Science 309:603-607] found much potential for conflict between conservation and agricultural human activity. This is not surprising because, like other global priority-setting approaches, they set priorities without socioeconomic objectives. Here we present a priority-setting framework that seeks to minimize the conflicts and opportunity costs of meeting conservation goals. We use it to derive a new set of priority areas for investment in mammal conservation based on (i) agricultural opportunity cost and biodiversity importance, (ii) current levels of international funding, and (iii) degree of threat. Our approach achieves the same biodiversity outcomes as Ceballos et al.'s while reducing the opportunity costs and conflicts with agricultural human activity by up to 50%. We uncover shortfalls in the allocation of conservation funds in many threatened priority areas, highlighting a global conservation challenge.

  View details for DOI 10.1073/pnas.0707157105

  View details for Web of Science ID 000258560700074

  View details for PubMedID 18678892

  View details for PubMedCentralID PMC2495010

• Where does biodiversity go from here? A grim business-as-usual forecast and a hopeful portfolio of partial solutions PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Ehrlich, P. R., Pringle, R. M. 2008; 105: 11579-11586

  Abstract

  The threats to the future of biodiversity are many and well known. They include habitat conversion, environmental toxification, climate change, and direct exploitation of wildlife, among others. Moreover, the projected addition of 2.6 billion people by mid-century will almost certainly have a greater environmental impact than that of the last 2.6 billion. Collectively, these trends portend a grim future for biodiversity under a business-as-usual scenario. These threats and their interactions are formidable, but we review seven strategies that, if implemented soundly and scaled up dramatically, would preserve a substantial portion of global biodiversity. These are actions to stabilize the human population and reduce its material consumption, the deployment of endowment funds and other strategies to ensure the efficacy and permanence of conservation areas, steps to make human-dominated landscapes hospitable to biodiversity, measures to account for the economic costs of habitat degradation, the ecological reclamation of degraded lands and repatriation of extirpated species, the education and empowerment of people in the rural tropics, and the fundamental transformation of human attitudes about nature. Like the carbon "stabilization wedges" outlined by Pacala and Socolow [Pacala S, Socolow R (2004) Stabilization wedges: Solving the climate problem for the next 50 years with current technologies. Science 305:968-972] (1), the science and technologies needed to effect this vision already exist. The remaining challenges are largely social, political, and economic. Although academic conservation biology still has an important role to play in developing technical tools and knowledge, success at this juncture hinges more on a massive mobilization of effort to do things that have traditionally been outside the scope of the discipline.

  View details for DOI 10.1073/pnas.0801911105

  View details for Web of Science ID 000258561200018

  View details for PubMedCentralID PMC2556413

• Antibiotic overuse: The influence of social norms JOURNAL OF THE AMERICAN COLLEGE OF SURGEONS Buchman, T. G., Dushoff, J., Effron, M. B., Ehrlich, P. R., FitzPatrick, S., Laxminarayan, R., Levin, B., Levin, S. A., Lipsitch, M., Malani, A., Nemeroff, C., Otto, S. P., Patel, V. L., Solomkin, J. S. 2008; 207 (2): 265-275

  View details for DOI 10.1016/j.jamcollsurg.2008.02.035

  View details for Web of Science ID 000258517600017

  View details for PubMedID 18656057

• Diversity, natural history and conservation of amphibians and reptiles from the San Vito Region, southwestern Costa Rica REVISTA DE BIOLOGIA TROPICAL Santos-Barrera, G., Pacheco, J., Mendoza-Quijano, F., Bolanos, F., Chaves, G., Daily, G. C., Ehrlich, P. R., Ceballos, G. 2008; 56 (2): 755-778

  Abstract

  We present an inventory of the amphibians and reptiles of the San Vito de Coto Brus region, including the Las Cruces Biological Station, in southern Costa Rica, which is the result of a survey of the herpetofauna occurring in mountain forest fragments, pastures, coffee plantations, and other disturbed areas. We found 67 species, included 26 species of amphibians and of 41 of reptiles. We describe the distribution patterns of the community on the basis of the life zones, elevation, fragmentation, and degree of anthropogenic impact. We also provide some nouvelle data on the systematics of some select taxa, their geographical ranges, microhabitats, activity, and other relevant ecological and natural history features. Finally, we comment on the present conservation status of the herpetofauna in the region. Previous literature and collection records indicate a higher number of species occurring in this area, which suggests that some declines have occurred, especially of amphibians, in last decades.

  View details for Web of Science ID 000259618700027

  View details for PubMedID 19256442

• Population, environment, war, and racism: Adventures of a public scholar ANTIPODE Ehrlich, P. R. 2008; 40 (3): 383-388

  View details for DOI 10.1111/j.1467-8330.2008.00604.x

  View details for Web of Science ID 000255135700006

• Natural selection and cultural rates of change PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Rogers, D. S., Ehrlich, P. R. 2008; 105 (9): 3416-3420

  Abstract

  It has been claimed that a meaningful theory of cultural evolution is not possible because human beliefs and behaviors do not follow predictable patterns. However, theoretical models of cultural transmission and observations of the development of societies suggest that patterns in cultural evolution do occur. Here, we analyze whether two sets of related cultural traits, one tested against the environment and the other not, evolve at different rates in the same populations. Using functional and symbolic design features for Polynesian canoes, we show that natural selection apparently slows the evolution of functional structures, whereas symbolic designs differentiate more rapidly. This finding indicates that cultural change, like genetic evolution, can follow theoretically derived patterns.

  View details for DOI 10.1073/pnas.0711802105

  View details for Web of Science ID 000253846500044

  View details for PubMedID 18287028

  View details for PubMedCentralID PMC2265130

• Demography and policy: A view from outside the discipline POPULATION AND DEVELOPMENT REVIEW Ehrlich, P. R. 2008; 34 (1): 103-?

  View details for Web of Science ID 000254127000005

• The biggest menace? (Bill McKibben, Allen Schill) NEW YORK REVIEW OF BOOKS Ehrlich, P. R., Ehrlich, A. H. 2008; 55 (2): 58

  View details for Web of Science ID 000252643200032

• Key issues for attention from ecological economists ENVIRONMENT AND DEVELOPMENT ECONOMICS Ehrlich, P. R. 2008; 13: 1-20

  View details for DOI 10.1017/S1355770X07004019

  View details for Web of Science ID 000252765900001

• Conservation of Coevolved Insect Herbivores and Plants SPECIALIZATION, SPECIATION, AND RADIATION: THE EVOLUTIONARY BIOLOGY OF HERBIVOROUS INSECTS Boggs, C. L., Ehrlich, P. R., Tilmon, K. J. 2008: 325–32

  View details for Web of Science ID 000293957200024

• Nature's economy and the human economy ENVIRONMENTAL & RESOURCE ECONOMICS Ehrlich, P. R., Ehrlich, A. H. 2008; 39 (1): 9-16

  View details for DOI 10.1007/s10640-007-9177-5

  View details for Web of Science ID 000252295200002

• Is current consumption excessive? A general framework and some indications for the United States CONSERVATION BIOLOGY Ehrlich, P. R., Goulder, L. H. 2007; 21 (5): 1145-1154

  Abstract

  Many prior studies have explored the implications of human population growth and environmentally problematic technologies for biodiversity loss and other forms of environmental degradation. Relatively few, however, have examined the impacts of the level and composition of consumption. We offer a framework that shows how the level and composition of a society's total consumption relate to the uses of various forms of capital and to the sustainability of natural resources and human well-being. We relate the framework to two main approaches-top-down macro studies and bottom-up computer models-for measuring whether overall consumption in the United States satisfies a sustainability requirement. Existing top-down studies have shortcomings that bias their results toward optimism, and current computer simulation models, although strong on revealing biophysical outcomes, are limited in their ability to evaluate impacts on human well-being. Although some ambiguities arise in determining whether overall consumption in the United States is excessive, our conclusions regarding the composition of U.S. consumption are unambiguous. Distorted consumption patterns and associated production methods lead to excessively rapid natural resource depletion; greater conservation would yield gains to current and future generations that more than compensate for the sacrifices involved. Public policies that deal with the composition problem not only would help conserve natural resources and improve current welfare but also would reduce the costs of meeting the goal of sustainability.

  View details for DOI 10.1111/j.1523-1739.2007-00779.x

  View details for Web of Science ID 000250008700006

  View details for PubMedID 17883480

• Consumption, investment, and future well-being: Reply to Daly et al. CONSERVATION BIOLOGY Arrow, K. J., Daily, G., Dasgupta, P., Ehrlich, P., Goulder, L., Heal, G., Levin, S., Maler, K., Schneider, S., Starrett, D., Walker, B. 2007; 21 (5): 1363-1365

  View details for DOI 10.1111/j.1523-1739.2007-00783.x

  View details for Web of Science ID 000250008700030

• Concerned scholars and intellectuals protest the imprisonment of Kian Tajbakhsh SOCIAL RESEARCH Appadurai, A., Ash, T. G., Chomsky, N., Cole, J. R., Crick, S. B., Ehrlich, P. R., Forman, S., Gottfried, K., Gross, J. T., Tomlinson, N. B., Habib, A., Hassim, S., Heller, A., Hirsch, E., Hoffman, E., Hoffmarm, S., Humphrey, N., Huszka, B., Isaac, J., Kerrey, B., Lubonja, F., Lukyanov, F., Margalit, A., Ullmann-Margalit, E., Mauer, M., Michnik, A., Oculi, O., Offe, C., Otieno, I. O., Power, S., Preuss, U. K., Prewitt, K., Ripstein, A., Schell, J., Zolberg, A. R. 2007; 74 (2): VIII-X

  View details for Web of Science ID 000248987900002

• Persistence of forest birds in the Costa Rican agricultural countryside CONSERVATION BIOLOGY Sekercioglu, C. H., Loarie, S. R., Brenes, F. O., Ehrlich, P. R., Daily, G. C. 2007; 21 (2): 482-494

  Abstract

  Understanding the persistence mechanisms of tropical forest species in human-dominated landscapes is a fundamental challenge of tropical ecology and conservation. Many species, including more than half of Costa Rica's native land birds, use mostly deforested agricultural countryside, but how they do so is poorly known. Do they commute regularly to forest or can some species survive in this human-dominated landscape year-round? Using radiotelemetry, we detailed the habitat use, movement, foraging, and nesting patterns of three bird species, Catharus aurantiirostris, Tangara icterocephala, and Turdus assimilis, by obtaining 8101 locations from 156 individuals. We chose forest birds that varied in their vulnerability to deforestation and were representative of the species found both in forest and human-dominated landscapes. Our study species did not commute from extensive forest; rather, they fed and bred in the agricultural countryside. Nevertheless, T. icterocephala and T. assimilis, which are more habitat sensitive, were highly dependent on the remaining trees. Although trees constituted only 11% of land cover, these birds spent 69% to 85% of their time in them. Breeding success of C. aurntiirostris and T. icterocephala in deforested habitats was not different than in forest remnants, where T. assimilis experienced reduced breeding success. Although this suggests an ecological trap for T. assimilis, higher fledgling survival in forest remnants may make up for lower productivity. Tropical countryside has high potential conservation value, which can be enhanced with even modest increases in tree cover. Our findings have applicability to many human-dominated tropical areas that have the potential to conserve substantial biodiversity if appropriate restoration measures are taken.

  View details for DOI 10.1111/j.1523-1739.2007.00655.x

  View details for Web of Science ID 000245438200024

  View details for PubMedID 17391198

• Bee community shifts with landscape context in a tropical countryside ECOLOGICAL APPLICATIONS Brosi, B. J., Daily, G. C., Ehrlich, P. R. 2007; 17 (2): 418-430

  Abstract

  The ongoing scientific controversy over a putative "global pollination crisis" underscores the lack of understanding of the response of bees (the most important taxon of pollinators) to ongoing global land-use changes. We studied the effects of distance to forest, tree management, and floral resources on bee communities in pastures (the dominant land-use type) in southern Costa Rica. Over two years, we sampled bees and floral resources in 21 pastures at three distance classes from a large (approximately 230-ha) forest patch and of three common types: open pasture; pasture with remnant trees; and pasture with live fences. We found no consistent differences in bee diversity or abundance with respect to pasture management or floral resources. Bee community composition, however, was strikingly different at forest edges as compared to deforested countryside only a few hundred meters from forest. At forest edges, native social stingless bees (Apidae: Meliponini) comprised approximately 50% of the individuals sampled, while the alien honeybee Apis mellifera made up only approximately 5%. Away from forests, meliponines dropped to approximately 20% of sampled bees, whereas Apis increased to approximately 45%. Meliponine bees were also more speciose at forest edge sites than at a distance from forest, their abundance decreased with continuous distance to the nearest forest patch, and their species richness was correlated with the proportion of forest cover surrounding sample sites at scales from 200 to 1200 m. Meliponines and Apis together comprise the eusocial bee fauna of the study area and are unique in quickly recruiting foragers to high-quality resources. The diverse assemblage of native meliponine bees covers a wide range of body sizes and flower foraging behavior not found in Apis, and populations of many bee species (including Apis), are known to fluctuate considerably from year to year. Thus, the forest-related changes in eusocial bee communities we found may have important implications for: (1) sustaining a diverse bee fauna in tropical countryside; (2) ensuring the effective pollination of a diverse native plant community; and (3) the efficiency and stability of agricultural pollination, particularly for short-time-scale, mass-flowering crops such as coffee.

  View details for Web of Science ID 000245744200011

  View details for PubMedID 17489249

• Genes, environments & behaviors DAEDALUS Ehrlich, P., Feldman, M. W. 2007; 136 (2): 5–12

  View details for DOI 10.1162/daed.2007.136.2.5

  View details for Web of Science ID 000245912900001

• When agendas collide: Human welfare and biological conservation CONSERVATION BIOLOGY Chan, K. M., Pringle, R. M., Ranganathan, J., Boggs, C. L., Chan, Y. L., Ehrlich, P. R., Haff, P. K., Heller, N. E., Al-Krafaji, K., Macmynowski, D. P. 2007; 21 (1): 59-68

  Abstract

  Conservation should benefit ecosystems, nonhuman organisms, and current and future human beings. Nevertheless, tension among these goals engenders potential ethical conflicts: conservationists' true motivations may differ from the justifications they offer for their activities, and conservation projects have the potential to disempower and oppress people. We reviewed the promise and deficiencies of integrating social, economic, and biological concerns into conservation, focusing on research in ecosystem services and efforts in community-based conservation. Despite much progress, neither paradigm provides a silver bullet for conservation's most pressing problems, and both require additional thought and modification to become maximally effective. We conclude that the following strategies are needed to make conservation more effective in our human-dominated world. (1) Conservation research needs to integrate with social scholarship in a more sophisticated manner. (2) Conservation must be informed by a detailed understanding of the spatial, temporal, and social distributions of costs and benefits of conservation efforts. Strategies should reflect this understanding, particularly by equitably distributing conservation's costs. (3) We must better acknowledge the social concerns that accompany biodiversity conservation; accordingly, sometimes we must argue for conservation for biodiversity's sake, not for its direct human benefits.

  View details for DOI 10.1111/j.1523-1739.2006.00570.x

  View details for Web of Science ID 000244148800014

  View details for PubMedID 17298511

• Range occupancy and endangerment: A test with a butterfly community AMERICAN MIDLAND NATURALIST Goehring, D. M., Daily, G. C., Dasgupta, S., Ehrlich, P. R. 2007; 157 (1): 106-120

  View details for Web of Science ID 000243956000009

• Global mammal distributions, biodiversity hotspots, and conservation PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Ceballos, G., Ehrlich, P. R. 2006; 103 (51): 19374-19379

  Abstract

  Hotspots, which have played a central role in the selection of sites for reserves, require careful rethinking. We carried out a global examination of distributions of all nonmarine mammals to determine patterns of species richness, endemism, and endangerment, and to evaluate the degree of congruence among hotspots of these three measures of diversity in mammals. We then compare congruence of hotspots in two animal groups (mammals and birds) to assess the generality of these patterns. We defined hotspots as the richest 2.5% of cells in a global equal-area grid comparable to 1 degrees latitude x 1 degrees longitude. Hotspots of species richness, "endemism," and extinction threat were noncongruent. Only 1% of cells and 16% of species were common to the three types of mammalian hotspots. Congruence increased with increases in both the geographic scope of the analysis and the percentage of cells defined as being hotspots. The within-mammal hotspot noncongruence was similar to the pattern recently found for birds. Thus, assigning global conservation priorities based on hotspots is at best a limited strategy.

  View details for DOI 10.1073/pnas.0609334103

  View details for Web of Science ID 000243166600029

  View details for PubMedID 17164331

  View details for PubMedCentralID PMC1698439

• Environmental science input to public policy SOCIAL RESEARCH Ehrlich, P. R. 2006; 73 (3): 915-948

  View details for Web of Science ID 000245473300016

• Enough already NEW SCIENTIST Ehrlich, P., Ehrlich, A. 2006; 191 (2571): 46-50

  View details for Web of Science ID 000241042900032

• Human impacts on the rates of recent, present, and future bird extinctions PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Pimm, S., Raven, P., Peterson, A., Sekercioglu, C. H., Ehrlich, P. R. 2006; 103 (29): 10941–46

  Abstract

  Unqualified, the statement that approximately 1.3% of the approximately 10,000 presently known bird species have become extinct since A.D. 1500 yields an estimate of approximately 26 extinctions per million species per year (or 26 E/MSY). This is higher than the benchmark rate of approximately 1 E/MSY before human impacts, but is a serious underestimate. First, Polynesian expansion across the Pacific also exterminated many species well before European explorations. Second, three factors increase the rate: (i) The number of known extinctions before 1800 is increasing as taxonomists describe new species from skeletal remains. (ii) One should calculate extinction rates over the years since taxonomists described the species. Most bird species were described only after 1850. (iii) Some species are probably extinct; there is reluctance to declare them so prematurely. Thus corrected, recent extinction rates are approximately 100 E/MSY. In the last decades, the rate is <50 E/MSY, but would be 150 E/MSY were it not for conservation efforts. Increasing numbers of extinctions are on continents, whereas previously most were on islands. We predict a 21st century rate of approximately 1,000 E/MSY. Extinction threatens 12% of bird species; another 12% have small geographical ranges and live where human actions rapidly destroy their habitats. If present forest losses continue, extinction rates will reach 1,500 E/MSY by the century's end. Invasive species, expanding human technologies, and global change will harm additional species. Birds are poor models for predicting extinction rates for other taxa. Human actions threaten higher fractions of other well known taxa than they do birds. Moreover, people take special efforts to protect birds.

  View details for DOI 10.1073/pnas.0604181103

  View details for Web of Science ID 000239327200023

  View details for PubMedID 16829570

  View details for PubMedCentralID PMC1544153

• Delayed population explosion of an introduced butterfly JOURNAL OF ANIMAL ECOLOGY Boggs, C. L., Holdren, C. E., Kulahci, I. G., Bonebrake, T. C., Inouye, B. D., Fay, J. P., McMillan, A., Williams, E. H., Ehrlich, P. R. 2006; 75 (2): 466-475

  Abstract

  1. The causes of lagged population and geographical range expansions after species introductions are poorly understood, and there are relatively few detailed case studies. 2. We document the 29-year history of population dynamics and structure for a population of Euphydryas gillettii Barnes that was introduced to the Colorado Rocky Mountains, USA in 1977. 3. The population size remained low (< 200 individuals) and confined to a single habitat patch (approximately 2.25 ha) to 1998. These values are similar to those of many other populations within the natural geographical range of the species. 4. However, by 2002 the population increased dramatically to > 3000 individuals and covered approximately 70 ha, nearly all to the south of the original site. The direction of population expansion was the same as that of predominant winds. 5. By 2004, the butterfly's local distribution had retracted mainly to three habitat patches. It thus exhibited a 'surge/contraction' form of population growth. Searches within 15 km of the original site yielded no other new populations. 6. In 2005, butterfly numbers crashed, but all three habitat patches remained occupied. The populations within each patch did not decrease in the same proportions, suggesting independent dynamics that are characteristic of metapopulations. 7. We postulate that this behaviour results, in this species, in establishment of satellite populations and, given appropriate habitat structure, may result in lagged or punctuated expansions of introduced populations.

  View details for DOI 10.1111/j.1365-2656.2006.01067.x

  View details for Web of Science ID 000236384700015

  View details for PubMedID 16637999

• Sustainability. Millennium assessment of human behavior. Science Ehrlich, P. R., Kennedy, D. 2005; 309 (5734): 562-563

  View details for PubMedID 16040693

• Global mammal conservation: What must we manage? SCIENCE Ceballos, G., Ehrlich, P. R., Soberon, J., Salazar, Fay, J. P. 2005; 309 (5734): 603–7

  Abstract

  We present a global conservation analysis for an entire "flagship" taxon, land mammals. A combination of rarity, anthropogenic impacts, and political endemism has put about a quarter of terrestrial mammal species, and a larger fraction of their populations, at risk of extinction. A new global database and complementarity analysis for selecting priority areas for conservation shows that approximately 11% of Earth's land surface should be managed for conservation to preserve at least 10% of terrestrial mammal geographic ranges. Different approaches, from protection (or establishment) of reserves to countryside biogeographic enhancement of human-dominated landscapes, will be required to approach this minimal goal.

  View details for DOI 10.1126/science.1114015

  View details for Web of Science ID 000230735200046

  View details for PubMedID 16040704

• The evolution of norms PLOS BIOLOGY Ehrlich, P. R., Levin, S. A. 2005; 3 (6): 943-948

  View details for DOI 10.1371/journal.pbio.0030194

  View details for Web of Science ID 000229992900001

  View details for PubMedID 15941355

  View details for PubMedCentralID PMC1149491

• Ecosystem consequences of bird declines PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Sekercioglu, C. H., Daily, G. C., Ehrlich, P. R. 2004; 101 (52): 18042-18047

  Abstract

  We present a general framework for characterizing the ecological and societal consequences of biodiversity loss and applying it to the global avifauna. To investigate the potential ecological consequences of avian declines, we developed comprehensive databases of the status and functional roles of birds and a stochastic model for forecasting change. Overall, 21% of bird species are currently extinction-prone and 6.5% are functionally extinct, contributing negligibly to ecosystem processes. We show that a quarter or more of frugivorous and omnivorous species and one-third or more of herbivorous, piscivorous, and scavenger species are extinction-prone. Furthermore, our projections indicate that by 2100, 6-14% of all bird species will be extinct, and 7-25% (28-56% on oceanic islands) will be functionally extinct. Important ecosystem processes, particularly decomposition, pollination, and seed dispersal, will likely decline as a result.

  View details for DOI 10.1073/pnas.0408049101

  View details for Web of Science ID 000226102700030

  View details for PubMedID 15601765

  View details for PubMedCentralID PMC539768

• Bioethics: Are our priorities right? Ehrlich, P. R. AMER INST BIOLOGICAL SCI. 2003: 1207–16

  View details for DOI 10.1641/0006-3568(2003)053[1207:BAOPR]2.0.CO;2

  View details for Web of Science ID 000187322200009

• Coping with uncertainty: A call for a new science-policy forum AMBIO Kinzig, A. P., Starrett, D., Arrow, K., Aniyar, S., Bolin, B., Dasgupta, P., Ehrlich, P., Folke, C., Hanemann, M., Heal, G., Hoel, M., Jansson, A., Jansson, B. O., Kautsky, N., Levin, S., Lubchenco, J., Maler, K. G., Pacala, S. W., Schneider, S. H., Siniscalco, D., Walker, B. 2003; 32 (5): 330-335

  Abstract

  The scientific and policy worlds have different goals, which can lead to different standards for what constitutes "proof" of a change or phenomena, and different approaches for characterizing and conveying uncertainty and risk. These differences can compromise effective communication among scientists, policymakers, and the public, and constrain the types of socially compelling questions scientists are willing to address. In this paper, we review a set of approaches for dealing with uncertainty, and illustrate some of the errors that arise when science and policy fail to coordinate correctly. We offer a set of recommendations, including restructuring of science curricula and establishment of science-policy forums populated by leaders in both arenas, and specifically constituted to address problems of uncertainty.

  View details for Web of Science ID 000185431000002

  View details for PubMedID 14571961

• Population diversity and ecosystem services TRENDS IN ECOLOGY & EVOLUTION Luck, G. W., Daily, G. C., Ehrlich, P. R. 2003; 18 (7): 331–36

  View details for DOI 10.1016/S0169-5347(03)00100-9

  View details for Web of Science ID 000184123500006

• Genes and cultures - What creates our behavioral phenome? CURRENT ANTHROPOLOGY Ehrlich, P., Feldman, M. 2003; 44 (1): 87-107

  View details for Web of Science ID 000180399900012

• Do hypotheses from short-term studies hold in the long-term? An empirical test ECOLOGICAL ENTOMOLOGY Hellmann, J. J., Weiss, S. B., McLaughlin, J. F., Boggs, C. L., Ehrlich, P. R., Launer, A. E., Murphy, D. D. 2003; 28 (1): 74-84

  View details for Web of Science ID 000181027100009

• Some roots of terrorism POPULATION AND ENVIRONMENT Ehrlich, P. R., Liu, J. G. 2002; 24 (2): 183-192

  View details for Web of Science ID 000179223900004

• The route to extinction: population dynamics of a threatened butterfly OECOLOGIA McLaughlin, J. F., Hellmann, J. J., Boggs, C. L., Ehrlich, P. R. 2002; 132 (4): 538-548

  Abstract

  We compare results of field study and model analysis of two butterfly populations to evaluate the importance of alternative mechanisms causing changes in abundance. Although understanding and predicting population fluctuations is a central goal of population ecology, it is not often achieved because long-term abundance data are available for few populations in which mechanisms causing fluctuations also are known. Both kinds of information exist for two populations of the checkerspot butterfly, Euphydryas editha bayensis, which are matched in most ways except for habitat area and topography. We applied results from field study to make predictions about the dynamics of the two populations. Then we tested these predictions using nonlinear modeling of abundance data. Models included endogenous factors, exogenous effects of weather, or both. Results showed that the populations differed in variability and responses to endogenous and exogenous factors. The population in the more homogeneous habitat varied more widely, went extinct first, and fluctuated more severely with climate. Dynamics of the population occupying the topographically diverse habitat were more complex, containing damped oscillations and weaker influences of weather. We draw four main conclusions. First, the routes to extinction for E. e. bayensis populations in protected habitat were random walks driven by climatic variability. Climatic influences dominated both populations, but the timing and functional forms of climatic effects differed between populations. Second, topographic diversity reduced weather-induced population variability and increased persistence time. Third, one must explicitly consider both endogenous and exogenous components to fully understand population dynamics. Fourth, resolving the debate over population regulation requires integrating long-term population sampling, model analysis, and investigation of mechanisms in the field.

  View details for DOI 10.1007/s00442-002-0997-2

  View details for Web of Science ID 000177866100008

• The route to extinction: population dynamics of a threatened butterfly. Oecologia McLaughlin, J. F., Hellmann, J. J., Boggs, C. L., Ehrlich, P. R. 2002; 132 (4): 538-548

  Abstract

  We compare results of field study and model analysis of two butterfly populations to evaluate the importance of alternative mechanisms causing changes in abundance. Although understanding and predicting population fluctuations is a central goal of population ecology, it is not often achieved because long-term abundance data are available for few populations in which mechanisms causing fluctuations also are known. Both kinds of information exist for two populations of the checkerspot butterfly, Euphydryas editha bayensis, which are matched in most ways except for habitat area and topography. We applied results from field study to make predictions about the dynamics of the two populations. Then we tested these predictions using nonlinear modeling of abundance data. Models included endogenous factors, exogenous effects of weather, or both. Results showed that the populations differed in variability and responses to endogenous and exogenous factors. The population in the more homogeneous habitat varied more widely, went extinct first, and fluctuated more severely with climate. Dynamics of the population occupying the topographically diverse habitat were more complex, containing damped oscillations and weaker influences of weather. We draw four main conclusions. First, the routes to extinction for E. e. bayensis populations in protected habitat were random walks driven by climatic variability. Climatic influences dominated both populations, but the timing and functional forms of climatic effects differed between populations. Second, topographic diversity reduced weather-induced population variability and increased persistence time. Third, one must explicitly consider both endogenous and exogenous components to fully understand population dynamics. Fourth, resolving the debate over population regulation requires integrating long-term population sampling, model analysis, and investigation of mechanisms in the field.

  View details for DOI 10.1007/s00442-002-0997-2

  View details for PubMedID 28547640

• Complexity and conservation: An ecological perspective - Response BIOSCIENCE Ehrlich, P. R. 2002; 52 (6): 461–62

  View details for DOI 10.1641/0006-3568(2002)052[0461:RFE]2.0.CO;2

  View details for Web of Science ID 000176233800003

• Mammal population losses and the extinction crisis SCIENCE Ceballos, G., Ehrlich, P. R. 2002; 296 (5569): 904-907

  Abstract

  The disappearance of populations is a prelude to species extinction. No geographically explicit estimates have been made of current population losses of major indicator taxa. Here we compare historic and present distributions of 173 declining mammal species from six continents. These species have collectively lost over 50% of their historic range area, mostly where human activities are intensive. This implies a serious loss of ecosystem services and goods. It also signals a substantial threat to species diversity.

  View details for Web of Science ID 000175442500042

  View details for PubMedID 11988573

• Climate change hastens population extinctions PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA McLaughlin, J. F., Hellmann, J. J., Boggs, C. L., Ehrlich, P. R. 2002; 99 (9): 6070-6074

  Abstract

  Climate change is expected to alter the distribution and abundance of many species. Predictions of climate-induced population extinctions are supported by geographic range shifts that correspond to climatic warming, but few extinctions have been linked mechanistically to climate change. Here we show that extinctions of two populations of a checkerspot butterfly were hastened by increasing variability in precipitation, a phenomenon predicted by global climate models. We model checkerspot populations to show that changes in precipitation amplified population fluctuations, leading to rapid extinctions. As populations of checkerspots and other species become further isolated by habitat loss, climate change is likely to cause more extinctions, threatening both species diversity and critical ecosystem services.

  View details for DOI 10.1073/pnas.052131199

  View details for Web of Science ID 000175377800059

  View details for PubMedID 11972020

  View details for PubMedCentralID PMC122903

• Disappearance of insectivorous birds from tropical forest fragments PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Sekercioglu, C. H., Ehrlich, P. R., Daily, G. C., Aygen, D., Goehring, D., Sandi, R. F. 2002; 99 (1): 263-267

  Abstract

  Determining the impact of forest disturbance and fragmentation on tropical biotas is a central goal of conservation biology. Among tropical forest birds, understory insectivores are particularly sensitive to habitat disturbance and fragmentation, despite their relatively small sizes and freedom from hunting pressure. Why these birds are especially vulnerable to fragmentation is not known. Our data indicate that the best determinant of the persistence of understory insectivorous birds in small fragments is the ability to disperse through deforested countryside habitats. This finding contradicts our initial hypothesis that the decline of insectivorous birds in forest fragments is caused by impoverished invertebrate prey base in fragments. Although we observed significantly fewer insectivorous birds in smaller fragments, extensive sampling of invertebrate communities (106,082 individuals) and avian diets (of 735 birds) revealed no important differences between large and small fragments. Neither habitat specificity nor drier fragment microclimates seemed critical. Bird species that were less affected by forest fragmentation were, in general, those that used the deforested countryside more, and we suggest that the key to their conservation will be found there.

  View details for Web of Science ID 000173233300049

  View details for PubMedID 11782549

• Human natures, nature conservation, and environmental ethics BIOSCIENCE Ehrlich, P. R. 2002; 52 (1): 31-43

  View details for Web of Science ID 000173456700010

• Intervening in evolution: Ethics and actions National-Academy-of-Sciences Colloquium on the Future of Evolution Ehrlich, P. R. NATL ACAD SCIENCES. 2001: 5477–80

  Abstract

  Biologists should help to guide a process of cultural evolution in which society determines how much effort, if any, is ethically required to preserve options in biological evolution. Evolutionists, conservation biologists, and ecologists should be doing more research to determine actions that would best help to avoid foreclosing evolutionary options.

  View details for Web of Science ID 000168623300021

  View details for PubMedID 11344297

  View details for PubMedCentralID PMC33237

• Conservation of Insect Diversity: a Habitat Approach. Conservation biology : the journal of the Society for Conservation Biology Hughes, J. B., Daily, G. C., Ehrlich, P. R. 2000; 14 (6): 1788-1797

  Abstract

  Neither time nor resources exist to design conservation plans for every species, particularly for little-studied, noncharismatic, but ecologically important taxa that make up most of biodiversity. To explore the feasibility of basing conservation action on community-level biogeography, we sampled a montane insect community. We addressed three issues: (1) the appropriate scale for sampling insect communities; (2) the association of habitat specialization-perhaps a measure of extinction vulnerability-with other ecological or physical traits; and (3) the correlation of diversity across major insect groups. Using malaise traps in Gunnison County, Colorado, we captured 8847 Diptera (identified to family and morphospecies), 1822 Hymenoptera (identified to morphospecies), and 2107 other insects (identified to order). We sampled in three habitat types-meadow, aspen, and conifer-defined on the basis of the dominant vegetation at the scale of hundreds of meters. Dipteran communities were clearly differentiated by habitat type rather than geographic proximity. This result also holds true for hymenopteran communities. Body size and feeding habits were associated with habitat specialization at the family level. In particular, habitat generalists at the family level-taxa perhaps more likely to survive anthropogenic habitat alteration-tended to be trophic generalists. Dipteran species richness was marginally correlated with hymenopteran species richness and was significantly correlated with the total number of insect orders sampled by site. Because these correlations result from differences in richness among habitat types, insect taxa may be reasonable surrogates for one another when sampling is done across habitat types. In sum, community-wide studies appear to offer a practical way to gather information about the diversity and distribution of little-known taxa.

  View details for DOI 10.1111/j.1523-1739.2000.99187.x

  View details for PubMedID 35701940

• Ecology - The value of nature and the nature of value SCIENCE Daily, G. C., Soderqvist, T., Aniyar, S., Arrow, K., Dasgupta, P., Ehrlich, P. R., Folke, C., Jansson, A., Jansson, B. O., Kautsky, N., Levin, S., Lubchenco, J., Maler, K. G., Simpson, D., Starrett, D., Tilman, D., Walker, B. 2000; 289 (5478): 395-396

  Abstract

  Ecosystems are capital assets: When properly managed, they yield a flow of vital goods and services. Relative to other forms of capital, however, ecosystems are poorly understood, scarcely monitored, and--in many important cases--undergoing rapid degradation. The process of economic valuation could greatly improve stewardship. This potential is now being realized with innovative financial instruments and institutional arrangements.

  View details for Web of Science ID 000088305500022

  View details for PubMedID 10939949

• Economic incentives for rain forest conservation across scales SCIENCE Kremen, C., Niles, J. O., Dalton, M. G., Daily, G. C., Ehrlich, P. R., Fay, J. P., Grewal, D., Guillery, R. P. 2000; 288 (5472): 1828-1832

  Abstract

  Globally, tropical deforestation releases 20 to 30% of anthropogenic greenhouse gases. Conserving forests could reduce emissions, but the cost-effectiveness of this mechanism for mitigation depends on the associated opportunity costs. We estimated these costs from local, national, and global perspectives using a case study from Madagascar. Conservation generated significant benefits over logging and agriculture locally and globally. Nationally, however, financial benefits from industrial logging were larger than conservation benefits. Such differing economic signals across scales may exacerbate tropical deforestation. The Kyoto Protocol could potentially overcome this obstacle to conservation by creating markets for protection of tropical forests to mitigate climate change.

  View details for Web of Science ID 000087503800051

  View details for PubMedID 10846165

• Donald Kennedy - The next Editor-in-Chief of Science SCIENCE Ehrlich, P. R. 2000; 288 (5470): 1349-1349

  View details for Web of Science ID 000087270900027

  View details for PubMedID 10847848

• Food production, population growth, and the environment. Science Daily, G., Dasgupta, P., Bolin, B., Crosson, P., du Guerny, J., Ehrlich, P., Folke, C., Jansson, A. M., Jansson, B., Kautsky, N., Kinzig, A., Levin, S., Mäler, K. G., Pinstrup-Andersen, P., Siniscalco, D., Walker, B. 1998; 281 (5381): 1291-1292

  View details for PubMedID 9735046

• Rivets and redundancy BIOSCIENCE Ehrlich, P., Walker, B. 1998; 48 (5): 387

  View details for DOI 10.2307/1313377

  View details for Web of Science ID 000073129100010

• Bird assemblages in patchy woodlands: Modeling the effects of edge and matrix habitats ECOLOGICAL APPLICATIONS Sisk, T. D., Haddad, N. M., Ehrlich, P. R. 1997; 7 (4): 1170-1180

  View details for Web of Science ID A1997YD79000012

• Population diversity: Its extent and extinction SCIENCE Hughes, J. B., Daily, G. C., Ehrlich, P. R. 1997; 278 (5338): 689-692

  Abstract

  Genetically distinct populations are an important component of biodiversity. This work estimates the number of populations per area of a sample of species from literature on population differentiation and the average range area of a species from a sample of distribution maps. This yields an estimate of about 220 populations per species, or 1.1 to 6.6 billion populations globally. Assuming that population extinction is a linear function of habitat loss, approximately 1800 populations per hour (16 million annually) are being destroyed in tropical forests alone.

  View details for Web of Science ID A1997YC32300055

  View details for PubMedID 9381179

• Ehrlichs' fables TECHNOLOGY REVIEW Ehrlich, P. R., Ehrlich, H. 1997; 100 (1): 38-47

  View details for Web of Science ID A1997VX00300022

• Nocturnality and species survival PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Daily, G. C., Ehrlich, P. R. 1996; 93 (21): 11709-11712

  Abstract

  Surveys of butterfly and moth diversity in tropical forest fragments suggest that nocturnality confers a dispersal, and possibly a survival, advantage. The butterfly faunas of smaller fragments were depauperate; in contrast, the species richness of nocturnal moths was similar in all fragments and even in pasture. The lack of correlation between butterfly and moth species richness among fragments (r2 = 0.005) is best explained by movements of moths at night when ambient conditions in forest and pasture are most similar; butterflies face substantial daytime temperature, humidity, and solar radiation barriers. This interpretation is supported by information on birds, beetles, and bats.

  View details for Web of Science ID A1996VM68100075

  View details for PubMedID 8876201

  View details for PubMedCentralID PMC38123

• Environmental anti-science TRENDS IN ECOLOGY & EVOLUTION Ehrlich, P. R. 1996; 11 (9): 393-393

  View details for Web of Science ID A1996VC82300018

  View details for PubMedID 21237892

• Conservation in temperate forests: What do we need to know and do? FOREST ECOLOGY AND MANAGEMENT Ehrlich, P. R. 1996; 85 (1-3): 9–19

  View details for DOI 10.1016/S0378-1127(96)03746-2

  View details for Web of Science ID A1996VZ10700002

• POPULATION AND IMMIGRATION POLICY IN THE UNITED-STATES - RESPONSE POPULATION AND ENVIRONMENT Daily, G. C., EHRLICH, A. H., Ehrlich, P. R. 1995; 16 (6): 521-526

  View details for Web of Science ID A1995RK77700004

• Influence of social status on individual foraging and community structure in a bird guild. Oecologia Daily, G. C., Ehrlich, P. R. 1994; 100 (1-2): 153-165

  Abstract

  We investigated the influence of social interactions on individual foraging behavior and community structure of frugivorous birds in southern Costa Rica. Detailed observations of large, heterospecific feeding assemblages at fruiting trees revealed the existence of an interspecific dominance hierarchy, largely consistent with body and bill size. Social status influenced access to food in several ways. First, subordinate species were interrupted more and tended to have shorter foraging bouts than dominant species (n > 1.000 abouts). Second, analysis of over 7,000 videotaped head movements showed that subordinate species spent a smaller fraction of their foraging bouts actually feeding (as opposed to looking about) than did dominants. Third, when many birds were in a tree simultaneously, the foraging bouts of subordinate species were shortened; this effect was less pronounced or absent for species higher in the dominance hierarchy. Fourth, subordinate species foraged less frequently in mixed-species assemblages than did dominant species. Finally, subordinate species fed disproportionately more in the late afternoon at fruiting trees. The influence of social status appeared to manifest itself at the community level. The species composition of foraging assemblages was compared at isolated fruiting trees situated in an agricultural landscape near to (< 0.5 km) and far from (> 6 km) a large tract of primary forest. Whereas the full complement of avian frugivores foraged at the near trees, visitors to the far trees were predominantly of high social status. We discuss reasons why high social status and associated traits might confer an advantage in exploiting human-dominated habitat.

  View details for DOI 10.1007/BF00317142

  View details for PubMedID 28307039

• INFLUENCE OF SOCIAL-STATUS ON INDIVIDUAL FORAGING AND COMMUNITY STRUCTURE IN A BIRD GUILD OECOLOGIA Daily, G. C., Ehrlich, P. R. 1994; 100 (1-2): 153-165

  Abstract

  We investigated the influence of social interactions on individual foraging behavior and community structure of frugivorous birds in southern Costa Rica. Detailed observations of large, heterospecific feeding assemblages at fruiting trees revealed the existence of an interspecific dominance hierarchy, largely consistent with body and bill size. Social status influenced access to food in several ways. First, subordinate species were interrupted more and tended to have shorter foraging bouts than dominant species (n > 1.000 abouts). Second, analysis of over 7,000 videotaped head movements showed that subordinate species spent a smaller fraction of their foraging bouts actually feeding (as opposed to looking about) than did dominants. Third, when many birds were in a tree simultaneously, the foraging bouts of subordinate species were shortened; this effect was less pronounced or absent for species higher in the dominance hierarchy. Fourth, subordinate species foraged less frequently in mixed-species assemblages than did dominant species. Finally, subordinate species fed disproportionately more in the late afternoon at fruiting trees. The influence of social status appeared to manifest itself at the community level. The species composition of foraging assemblages was compared at isolated fruiting trees situated in an agricultural landscape near to (< 0.5 km) and far from (> 6 km) a large tract of primary forest. Whereas the full complement of avian frugivores foraged at the near trees, visitors to the far trees were predominantly of high social status. We discuss reasons why high social status and associated traits might confer an advantage in exploiting human-dominated habitat.

  View details for Web of Science ID A1994PR64500019

• IDENTIFYING EXTINCTION THREATS BIOSCIENCE SISK, T. D., LAUNER, A. E., SWITKY, K. R., EHRLICH, P. R. 1994; 44 (9): 592–604

  View details for DOI 10.2307/1312459

  View details for Web of Science ID A1994PJ53000006

• TECHNIQUES AND GUIDELINES FOR MONITORING NEOTROPICAL BUTTERFLIES CONSERVATION BIOLOGY SPARROW, H. R., SISK, T. D., EHRLICH, P. R., MURPHY, D. D. 1994; 8 (3): 800–809

  View details for DOI 10.1046/j.1523-1739.1994.08030800.x

  View details for Web of Science ID A1994PF73000026

• Estimating female reproductive success of a threatened butterfly: influence of emergence time and hostplant phenology. Oecologia Cushman, J. H., Boggs, C. L., Weiss, S. B., Murphy, D. D., Harvey, A. W., Ehrlich, P. R. 1994; 99 (1-2): 194-200

  Abstract

  We estimated lifetime reproductive success of Euphydryas editha bayensis (Nymphalidae), a federally listed threatened butterfly, based on age-specific fecundity and both adult and offspring survival. Our results indicate that the relative timing of adult emergence and larval hosplant senescence strongly influenced reproductive success of females. For 1992, we estimated that only 8-21% of the eggs laid by females emerging on the 1st day of the 4-week flight season would produce larvae that reach diapause. This figure dropped to 1-5% for females emerging 7 days into the flight season. Within our entire sample, we estimated that 64-88% of the females produced offspring with less than a 2% probability of reaching diapause. These estimates are particularly striking given that they are based on only one source of larval mortality - prediapause starvation due to hostplant senescence. This dependence of reproductive success on the relative timing of female emergence and hostplant senescence may reduce effective population size and render E. editha bayensis especially vulnerable to local extinction events.

  View details for DOI 10.1007/BF00317101

  View details for PubMedID 28313966

• ESTIMATING FEMALE REPRODUCTIVE SUCCESS OF A THREATENED BUTTERFLY - INFLUENCE OF EMERGENCE TIME AND HOSTPLANT PHENOLOGY OECOLOGIA Cushman, J. H., Boggs, C. L., Weiss, S. B., Murphy, D. D., Harvey, A. W., Ehrlich, P. R. 1994; 99 (1-2): 194-200

  Abstract

  We estimated lifetime reproductive success of Euphydryas editha bayensis (Nymphalidae), a federally listed threatened butterfly, based on age-specific fecundity and both adult and offspring survival. Our results indicate that the relative timing of adult emergence and larval hosplant senescence strongly influenced reproductive success of females. For 1992, we estimated that only 8-21% of the eggs laid by females emerging on the 1st day of the 4-week flight season would produce larvae that reach diapause. This figure dropped to 1-5% for females emerging 7 days into the flight season. Within our entire sample, we estimated that 64-88% of the females produced offspring with less than a 2% probability of reaching diapause. These estimates are particularly striking given that they are based on only one source of larval mortality - prediapause starvation due to hostplant senescence. This dependence of reproductive success on the relative timing of female emergence and hostplant senescence may reduce effective population size and render E. editha bayensis especially vulnerable to local extinction events.

  View details for Web of Science ID A1994PJ34100026

• OPTIMUM HUMAN-POPULATION SIZE POPULATION AND ENVIRONMENT Daily, G. C., EHRLICH, A. H., Ehrlich, P. R. 1994; 15 (6): 469-475

  View details for Web of Science ID A1994NX24600003

• ENERGY USE AND BIODIVERSITY LOSS PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY OF LONDON SERIES B-BIOLOGICAL SCIENCES EHRLICH, P. R. 1994; 344 (1307): 99–104

  View details for DOI 10.1098/rstb.1994.0057

  View details for Web of Science ID A1994NM57000015

• ENHANCING THE STATUS OF POPULATION BIOLOGY TRENDS IN ECOLOGY & EVOLUTION Ehrlich, P. R. 1994; 9 (4): 157-157

  View details for Web of Science ID A1994NB39500015

  View details for PubMedID 21236805

• ECOLOGICAL ECONOMICS AND THE CARRYING-CAPACITY OF EARTH 1992 Wallenberg Workshop Ehrlich, P. R. ISLAND PRESS. 1994: 38–56

  View details for Web of Science ID A1994BA79K00003

• Adult emergence phenology in checkerspot butterflies: the effects of macroclimate, topoclimate, and population history. Oecologia Weiss, S. B., Murphy, D. D., Ehrlich, P. R., Metzler, C. F. 1993; 96 (2): 261-270

  Abstract

  The prediction of adult emergence times in insect populations can be greatly complicated by microclimatic gradients, especially in circumstances where distributions of juveniles along those gradients vary from year to year. To investigate adult emergence patterns in topographically heterogeneous habitats, we built a model of postdiapause development of the Bay checkerspot butterfly, Euphydryas editha bayensis. The model uses slope-specific insolation as the rate-controlling variable, and accounts for both solar exposure of the habitat and cloud cover. Instar-specific larval mass gains per unit of insolation were determined from mark-recapture experiments. A small correction for daily low temperatures was used to calibrate the model to five years of field data on larval mass. The model predicted mean mass of 90% of larval samples within 4 clear days over a 70-120 day growing season. The magnitude of spatial variation in emergence times across habitat slopes is greater than annual variation in emergence times due to yearly weather conditions. Historical variation (yearly shifts in larval distributions across slopes) is an important determinant of mean population emergence dates. All of these factors need to be considered in understanding adult emergence phenology in this butterfly and in other insects inhabiting heterogeneous thermal environments. Such an understanding can be useful in managing insect populations for both pest control and conservation.

  View details for DOI 10.1007/BF00317740

  View details for PubMedID 28313423

• ADULT EMERGENCE PHENOLOGY IN CHECKERSPOT BUTTERFLIES - THE EFFECTS OF MACROCLIMATE, TOPOCLIMATE, AND POPULATION HISTORY OECOLOGIA Weiss, S. B., Murphy, D. D., Ehrlich, P. R., METZLER, C. F. 1993; 96 (2): 261-270

  Abstract

  The prediction of adult emergence times in insect populations can be greatly complicated by microclimatic gradients, especially in circumstances where distributions of juveniles along those gradients vary from year to year. To investigate adult emergence patterns in topographically heterogeneous habitats, we built a model of postdiapause development of the Bay checkerspot butterfly, Euphydryas editha bayensis. The model uses slope-specific insolation as the rate-controlling variable, and accounts for both solar exposure of the habitat and cloud cover. Instar-specific larval mass gains per unit of insolation were determined from mark-recapture experiments. A small correction for daily low temperatures was used to calibrate the model to five years of field data on larval mass. The model predicted mean mass of 90% of larval samples within 4 clear days over a 70-120 day growing season. The magnitude of spatial variation in emergence times across habitat slopes is greater than annual variation in emergence times due to yearly weather conditions. Historical variation (yearly shifts in larval distributions across slopes) is an important determinant of mean population emergence dates. All of these factors need to be considered in understanding adult emergence phenology in this butterfly and in other insects inhabiting heterogeneous thermal environments. Such an understanding can be useful in managing insect populations for both pest control and conservation.

  View details for Web of Science ID A1993MH78700015

• THE EFFECT OF FLUORESCENT PIGMENTS ON BUTTERFLY COPULATION ECOLOGICAL ENTOMOLOGY FLEISHMAN, E., BAUGHMAN, J. F., LAUNER, A. E., EHRLICH, P. R. 1993; 18 (2): 165–67

  View details for DOI 10.1111/j.1365-2311.1993.tb01198.x

  View details for Web of Science ID A1993LJ18200010

• FOOD SECURITY, POPULATION, AND ENVIRONMENT POPULATION AND DEVELOPMENT REVIEW Ehrlich, P. R., EHRLICH, A. H., Daily, G. C. 1993; 19 (1): 1-32

  View details for Web of Science ID A1993LF02300001

• DOUBLE KEYSTONE BIRD IN A KEYSTONE SPECIES COMPLEX PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Daily, G. C., Ehrlich, P. R., Haddad, N. M. 1993; 90 (2): 592-594

  Abstract

  Species in a Colorado subalpine ecosystem show subtle interdependences. Red-naped sapsuckers play two distinct keystone roles. They excavate nest cavities in fungus-infected aspens that are required as nest sites by two species of swallows, and they drill sap wells into willows that provide abundant nourishment for themselves, hummingbirds, orange-crowned warblers, chipmunks, and an array of other sap robbers. The swallows thus depend on, and the sap robbers benefit from, a keystone species complex comprised of sapsuckers, willows, aspens, and a heartwood fungus. Disappearance of any element of the complex could cause an unanticipated unraveling of the community.

  View details for Web of Science ID A1993KH51600048

  View details for PubMedID 11607351

  View details for PubMedCentralID PMC45709

• ONE ECOLOGISTS OPINION ON THE SO-CALLED STANFORD SCANDALS AND SOCIAL-RESPONSIBILITY BIOSCIENCE Ehrlich, P. R. 1992; 42 (9): 702-705

  View details for Web of Science ID A1992JQ82200008

• THE VALUE OF BIODIVERSITY AMBIO Ehrlich, P. R., EHRLICH, A. H. 1992; 21 (3): 219-226

  View details for Web of Science ID A1992HY68900005

• THE CHALLENGES OF CONSERVATION BIOLOGY ECOLOGICAL APPLICATIONS BRUSSARD, P. F., EHRLICH, P. R. 1992; 2 (1): 1–2

  View details for DOI 10.2307/1941884

  View details for Web of Science ID A1992JM28300001

  View details for PubMedID 27759191

• Determinants of spatial distribution in a population of the subalpine butterfly Oeneis chryxus. Oecologia Daily, G. C., Ehrlich, P. R., Wheye, D. 1991; 88 (4): 587-596

  Abstract

  This paper describes temporally varying determinants of the spatial distribution of adults in an insect population and the relationship between that distribution and the mating system. Male Oeneis chryxus butterflies were distributed nonrandomly throughout a sloping Colorado meadow divided horizontally by a dirt road into an upper and lower slope. Over an eight-year period of intensive study, the proportion of males located on the road, the upper slope, and the lower slope varied as a function of population size and sex ratio. In each year, more than half of the male population aggregated on sections of the road in a distinct and recurring pattern that was not correlated with the distribution of any food resource or thermal regime. Females were usually extremely scarce and not distributed in any pattern apparent from the few observations of them. Areas densely occupied by males were associated with visual landmarks. We hypothesize that the male distribution is determined by a pattern of movement of receptive females toward these landmarks. The road offers a thermally favorable environment with an unobstructed view in which to await the passage of scarce females. The mating system in this population has several lek-like features and supports the prediction that landmark mating is a favored strategy under conditions of female scarcity and wide dispersal of resources.

  View details for DOI 10.1007/BF00317724

  View details for PubMedID 28312631

• POPULATION-GROWTH AND ENVIRONMENTAL SECURITY GEORGIA REVIEW Ehrlich, P. R., EHRLICH, A. H. 1991; 45 (2): 223-232

  View details for Web of Science ID A1991GD43200001

• WEVE RUN THE TEST POPULATION AND ENVIRONMENT Ehrlich, P. R. 1991; 12 (3): 189-191

  View details for Web of Science ID A1991EY90100002

• DETERMINANTS OF SPATIAL-DISTRIBUTION IN A POPULATION OF THE SUB-ALPINE BUTTERFLY OENEIS-CHRYXUS OECOLOGIA Daily, G. C., Ehrlich, P. R., WHEYE, D. 1991; 88 (4): 587-596

  Abstract

  This paper describes temporally varying determinants of the spatial distribution of adults in an insect population and the relationship between that distribution and the mating system. Male Oeneis chryxus butterflies were distributed nonrandomly throughout a sloping Colorado meadow divided horizontally by a dirt road into an upper and lower slope. Over an eight-year period of intensive study, the proportion of males located on the road, the upper slope, and the lower slope varied as a function of population size and sex ratio. In each year, more than half of the male population aggregated on sections of the road in a distinct and recurring pattern that was not correlated with the distribution of any food resource or thermal regime. Females were usually extremely scarce and not distributed in any pattern apparent from the few observations of them. Areas densely occupied by males were associated with visual landmarks. We hypothesize that the male distribution is determined by a pattern of movement of receptive females toward these landmarks. The road offers a thermally favorable environment with an unobstructed view in which to await the passage of scarce females. The mating system in this population has several lek-like features and supports the prediction that landmark mating is a favored strategy under conditions of female scarcity and wide dispersal of resources.

  View details for Web of Science ID A1991GU19000019

• AN EXPLORATORY MODEL OF THE IMPACT OF RAPID CLIMATE CHANGE ON THE WORLD FOOD SITUATION PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES Daily, G. C., Ehrlich, P. R. 1990; 241 (1302): 232-244

  Abstract

  A simple, globally aggregated, stochastic-simulation model was constructed to examine the effects of rapid climatic change on agriculture and the human population. The model calculates population size and the production, consumption and storage of grain under different climate scenarios over a 20-year projection time. In most scenarios, either an optimistic baseline annual increase of agricultural output of 1.7% or a more pessimistic appraisal of 0.9% was used. The rate of natural increase of the human population exclusive of excess hunger-related deaths was set as 1.7% per year and climatic changes with both negative and positive impacts on agriculture were assessed. Analysis of the model suggests that the number of hunger-related deaths could double (with reference to an estimated 200 million deaths in the past two decades) if grain production keeps pace with population growth but climatic conditions are unfavourable. If the rate of increase in grain production is about half that of population growth, the number of hunger-related deaths could increase about fivefold (over past levels); the impact of climatic change is relatively small under this imbalance. Even favourable climatic changes that enhance agricultural production may not prevent a fourfold increase in deaths (over past levels) under scenarios where population growth outpaces production by about 0.8% per annum. These results may foreshadow a fundamental change where, for the first time, absolute global food deficits compound inequities in food production and distribution in causing famine. The model also highlights the effectiveness of reducing population growth rates as a strategy for minimizing the impact of global climate change and maintaining food supplies for everyone.

  View details for Web of Science ID A1990ED14900012

  View details for PubMedID 1979448

• HABITATS IN CRISIS - WHY WE SHOULD CARE ABOUT THE LOSS OF SPECIES FOREST ECOLOGY AND MANAGEMENT Ehrlich, P. R. 1990; 35 (1-2): 5-11

  View details for Web of Science ID A1990DT32800002

• A REEXAMINATION OF HILLTOPPING IN EUPHYDRYAS-EDITHA OECOLOGIA BAUGHMAN, J. F., Murphy, D. D., Ehrlich, P. R. 1990; 83 (2): 259-260

  View details for Web of Science ID A1990DG37300017

  View details for PubMedID 22160120

• INTELLIGENT PLANNING FOR SAFETY SOCIETY Ehrlich, P. R., EHRLICH, A. H. 1989; 27 (1): 15-16

  View details for Web of Science ID A1989AZ32000007

• THE ENVIRONMENTAL DIMENSIONS OF NATIONAL-SECURITY PUGWASH CONF ON GLOBAL PROBLEMS AND COMMON SECURITY Ehrlich, P., Ehrlich, A. SPRINGER-VERLAG BERLIN. 1989: 180–190

  View details for Web of Science ID A1989BP81S00024

• PLANT CHEMISTRY AND HOST RANGE IN INSECT HERBIVORES ECOLOGY Ehrlich, P. R., Murphy, D. D. 1988; 69 (4): 908-909

  View details for Web of Science ID A1988P723500008

• POPULATION-STRUCTURE OF A HILLTOPPING BUTTERFLY OECOLOGIA BAUGHMAN, J. F., Murphy, D. D., Ehrlich, P. R. 1988; 75 (4): 593-600

  View details for Web of Science ID A1988N205500017

• WHY THE CLUB OF EARTH TRENDS IN ECOLOGY & EVOLUTION Ehrlich, P. R. 1987; 2 (5): 133-135

  Abstract

  Recently, a small group of ecologists and evolutionary biologists anointed themselves The Club of Earth and made a public pronouncement on the importance of preserving biological diversity. For me, the most frequent result of being a member has been a series of queries about why the group had been formed.

  View details for Web of Science ID A1987H511700007

  View details for PubMedID 21227835

• HUMAN APPROPRIATION OF THE PRODUCTS OF PHOTOSYNTHESIS BIOSCIENCE Vitousek, P. M., Ehrlich, P. R., EHRLICH, A. H., Matson, P. A. 1986; 36 (6): 368-373

  View details for Web of Science ID A1986C429000006

• Insular biogeography of the montane butterfly faunas in the Great Basin: comparison with birds and mammals. Oecologia Wilcox, B. A., Murphy, D. D., Ehrlich, P. R., Austin, G. T. 1986; 69 (2): 188-194

  Abstract

  Butterfly species lists were assembled for 18 Great Basin mountain ranges for which distributional data on mammals and birds have been analysed previously by other workers. The ranges represent remnant islands of the boreal habitat that once was continuous across the Great Basin but is now restricted to higher elevations as a result of climatic change at the close of the Pleistocene. The effects of biogeographic factors (area, distance, elevation) and habitat diversity on butterfly species number were examined. The Great Basin boreal butterfly faunas were found to be depauperate overall relative that of the principal mainland source, the Rocky Mountains, and were found to have fewer species than predicted by the mainland species-area data. However, only a weak area effect, and no distance effect, was detected by bivariate and multivariate analysis. Furthermore, the habitat diversity score found to explain virtually all the variation in bird species number in the same ranges in previous studies is only marginally significantly correlated with butterflies. When the butterflies are subdivided according to their vagility, the relative differences in the species-area correlation and slope (z-value) between the vagility categories were consistent with those found previously for mammals and birds, and, as predicted by theory, less vagile taxa exhibit higher species-area correlations and z-values. Overall, differences in the insular biogeography of buttterflies and vertebrates seem to reflect fundamental ecological differences between the taxa.

  View details for DOI 10.1007/BF00377620

  View details for PubMedID 28311357

• WORLD-POPULATION CRISIS BULLETIN OF THE ATOMIC SCIENTISTS Ehrlich, P. R., EHRLICH, A. H. 1986; 42 (4): 13-19

  View details for Web of Science ID A1986A658000006

• INSULAR BIOGEOGRAPHY OF THE MONTANE BUTTERFLY FAUNAS IN THE GREAT-BASIN - COMPARISON WITH BIRDS AND MAMMALS OECOLOGIA Wilcox, B. A., Murphy, D. D., Ehrlich, P. R., Austin, G. T. 1986; 69 (2): 188-194

  Abstract

  Butterfly species lists were assembled for 18 Great Basin mountain ranges for which distributional data on mammals and birds have been analysed previously by other workers. The ranges represent remnant islands of the boreal habitat that once was continuous across the Great Basin but is now restricted to higher elevations as a result of climatic change at the close of the Pleistocene. The effects of biogeographic factors (area, distance, elevation) and habitat diversity on butterfly species number were examined. The Great Basin boreal butterfly faunas were found to be depauperate overall relative that of the principal mainland source, the Rocky Mountains, and were found to have fewer species than predicted by the mainland species-area data. However, only a weak area effect, and no distance effect, was detected by bivariate and multivariate analysis. Furthermore, the habitat diversity score found to explain virtually all the variation in bird species number in the same ranges in previous studies is only marginally significantly correlated with butterflies. When the butterflies are subdivided according to their vagility, the relative differences in the species-area correlation and slope (z-value) between the vagility categories were consistent with those found previously for mammals and birds, and, as predicted by theory, less vagile taxa exhibit higher species-area correlations and z-values. Overall, differences in the insular biogeography of buttterflies and vertebrates seem to reflect fundamental ecological differences between the taxa.

  View details for Web of Science ID A1986C318800005

• DURATION OF FEMALE AVAILABILITY AND ITS EFFECT ON BUTTERFLY MATING SYSTEMS AMERICAN NATURALIST Odendaal, F. J., Iwasa, Y., Ehrlich, P. R. 1985; 125 (5): 673-678

  View details for Web of Science ID A1985AHJ7600003

• A MIGRATION OF URANIA-FULGENS (URANIIDAE) IN COSTA-RICA BIOTROPICA Odendaal, F. J., Ehrlich, P. R. 1985; 17 (1): 46-49

  View details for Web of Science ID A1985AFM5700007

• HUMAN-ECOLOGY FOR INTRODUCTORY BIOLOGY COURSES - AN OVERVIEW AMERICAN ZOOLOGIST Ehrlich, P. R. 1985; 25 (2): 379-394

  View details for Web of Science ID A1985AKZ4900010

• THE USE OF FLUORESCENT PIGMENTS TO STUDY INSECT BEHAVIOR - INVESTIGATING MATING PATTERNS IN A BUTTERFLY POPULATION ECOLOGICAL ENTOMOLOGY WHEYE, D., Ehrlich, P. R. 1985; 10 (2): 231-234

  View details for Web of Science ID A1985AMH1800013

• Nectar source distribution as a determinant of oviposition host species in Euphydryas chalcedona. Oecologia Murphy, D. D., Menninger, M. S., Ehrlich, P. R. 1984; 62 (2): 269-271

  Abstract

  The distribution of nectar sources is shown to affect both the distribution of adult Euphydryas chalcedona and their offspring. We suggest that nectar sources thereby influence the selection of oviposition host plant species in habitats where those species are spacially separated.

  View details for DOI 10.1007/BF00379025

  View details for PubMedID 28310725

• NECTAR SOURCE DISTRIBUTION AS A DETERMINANT OF OVIPOSITION HOST SPECIES IN EUPHYDRYAS-CHALCEDONA OECOLOGIA Murphy, D. D., MENNINGER, M. S., Ehrlich, P. R. 1984; 62 (2): 269-271

  Abstract

  The distribution of nectar sources is shown to affect both the distribution of adult Euphydryas chalcedona and their offspring. We suggest that nectar sources thereby influence the selection of oviposition host plant species in habitats where those species are spacially separated.

  View details for Web of Science ID A1984SV09400020

• BIOLOGICAL INTERACTIONS. Evolution; international journal of organic evolution Ehrlich, P. R. 1984; 38 (1): 226-227

  View details for DOI 10.1111/j.1558-5646.1984.tb00276.x

  View details for PubMedID 28556072

• CITATION CLASSIC - BUTTERFLIES AND PLANTS - A STUDY IN COEVOLUTION CURRENT CONTENTS/AGRICULTURE BIOLOGY & ENVIRONMENTAL SCIENCES Ehrlich, P. R. 1984: 16-16

  View details for Web of Science ID A1984TF87600001

• NORTH-AMERICA AFTER THE WAR NATURAL HISTORY Ehrlich, P. R. 1984; 93 (3): 4-?

  View details for Web of Science ID A1984SD08500001

• CITATION CLASSIC - BUTTERFLIES AND PLANTS - A STUDY IN COEVOLUTION CURRENT CONTENTS/LIFE SCIENCES Ehrlich, P. R. 1984: 16-16

  View details for Web of Science ID A1984TF87200001

• The role of adult feeding in egg production and population dynamics of the checkerspot butterfly Euphydryas editha. Oecologia Murphy, D. D., Launer, A. E., Ehrlich, P. R. 1983; 56 (2-3): 257-263

  Abstract

  Carbohydrate intake increases longevity, body weight maintenance and egg production in female Euphydryas editha. Amino acid intake leads to heavier eggs, larvae from which are more likely to survive. Females fed nectar produce more eggs in later masses than females which are not fed. During years of normal and below normal precipitation, larvae emerging from these later eggs are unlikely to reach obligatory size for diapause before their food dries up. On Jasper Ridge, where mortality is density-independent, nectar plays an important role increasing production of late egg masses during years of greater than normal rainfall when larvae from these masses are likely to reach diapause. The resulting large population increases, though infrequent, are probably important in maintaining population sizes large enough to reduce the chances of extinction during dry years.

  View details for DOI 10.1007/BF00379699

  View details for PubMedID 28310203

• EXTINCTION, SUBSTITUTION, AND ECOSYSTEM SERVICES BIOSCIENCE Ehrlich, P. R., Mooney, H. A. 1983; 33 (4): 248-254

  View details for Web of Science ID A1983QX72700006

• THE ROLE OF ADULT FEEDING IN EGG-PRODUCTION AND POPULATION-DYNAMICS OF THE CHECKERSPOT BUTTERFLY EUPHYDRYAS-EDITHA OECOLOGIA Murphy, D. D., Launer, A. E., Ehrlich, P. R. 1983; 56 (2-3): 257-263

  Abstract

  Carbohydrate intake increases longevity, body weight maintenance and egg production in female Euphydryas editha. Amino acid intake leads to heavier eggs, larvae from which are more likely to survive. Females fed nectar produce more eggs in later masses than females which are not fed. During years of normal and below normal precipitation, larvae emerging from these later eggs are unlikely to reach obligatory size for diapause before their food dries up. On Jasper Ridge, where mortality is density-independent, nectar plays an important role increasing production of late egg masses during years of greater than normal rainfall when larvae from these masses are likely to reach diapause. The resulting large population increases, though infrequent, are probably important in maintaining population sizes large enough to reduce the chances of extinction during dry years.

  View details for Web of Science ID A1983QD66500017

• ECOLOGICAL DETERMINANTS OF FOOD PLANT CHOICE IN THE CHECKERSPOT BUTTERFLY EUPHYDRYAS-EDITHA IN COLORADO OECOLOGIA Holdren, C. E., Ehrlich, P. R. 1982; 52 (3): 417-423

  Abstract

  The larvae of Euphydryas editha in Gunnison County, Colorado, feed on Castilleja linariifolia. Two related plants, C. chromosa and Penstemon strictus, occur in the same area and are equally nutritious, but are not eaten. Restriction to C. linariifolia appears to be a case of ecological monophagy - survival on the other two species is less likely not because of their biochemical make-up but because of their ecological characteristics, primarily their phenologies.

  View details for Web of Science ID A1982NH64800020

• SOCIAL-BEHAVIOR OF BUTTERFLY AND SURGEONFISHES ON CORAL REEFS - SOME MIRROR EXPERIMENTS OECOLOGIA EHRLICH, P. R., EHRLICH, A. H. 1982; 54 (1): 138–40

  Abstract

  Chaetodontids and acanthurids showed behavior that suggested the existence of dominance systems. There was no sign that the poster colors of chaetodontids serve as territorial signals, and there were interspecific differences in their responses to the mirror. Aggressive butterfly fishes usually butted with the spines of the forward part of the dorsal fin; surgeonfishes used their scalpels in attacks against their images.

  View details for PubMedID 28311005

• Ecological determinants of food plant choice in the checkerspot butterfly Euphydryas editha in Colorado. Oecologia Holdren, C. E., Ehrlich, P. R. 1982; 52 (3): 417-423

  Abstract

  The larvae of Euphydryas editha in Gunnison County, Colorado, feed on Castilleja linariifolia. Two related plants, C. chromosa and Penstemon strictus, occur in the same area and are equally nutritious, but are not eaten. Restriction to C. linariifolia appears to be a case of ecological monophagy - survival on the other two species is less likely not because of their biochemical make-up but because of their ecological characteristics, primarily their phenologies.

  View details for DOI 10.1007/BF00367970

  View details for PubMedID 28310406

• HUMAN CARRYING-CAPACITY, EXTINCTIONS, AND NATURE RESERVES BIOSCIENCE Ehrlich, P. R. 1982; 32 (5): 331-333

  View details for Web of Science ID A1982NS78000011

• Long range dispersal in checkerspot butterflies: Transplant experiments with Euphydryas gillettii. Oecologia Holdren, C. E., Ehrlich, P. R. 1981; 50 (1): 125-129

  Abstract

  Transfers of eggs and larvae from montane Wyoming populations of Euphydryas gillettii south to locations in the central Colorado mountains have resulted in the establishment of at least one Colorado population. This result shows that the previous absence of the species from Colorado was the result of its inability to cross the barrier of the Wyoming Basin, not the ecological unsuitability of Colorado habitats. This, in turn, supports the contention that Euphydryas do not easily disperse long distances.

  View details for DOI 10.1007/BF00378805

  View details for PubMedID 28310073

• LONG-RANGE DISPERSAL IN CHECKERSPOT BUTTERFLIES - TRANSPLANT EXPERIMENTS WITH EUPHYDRYAS-GILLETTII OECOLOGIA Holdren, C. E., Ehrlich, P. R. 1981; 50 (1): 125-129

  Abstract

  Transfers of eggs and larvae from montane Wyoming populations of Euphydryas gillettii south to locations in the central Colorado mountains have resulted in the establishment of at least one Colorado population. This result shows that the previous absence of the species from Colorado was the result of its inability to cross the barrier of the Wyoming Basin, not the ecological unsuitability of Colorado habitats. This, in turn, supports the contention that Euphydryas do not easily disperse long distances.

  View details for Web of Science ID A1981MD22000018

• THE POLITICS OF EXTINCTION BULLETIN OF THE ATOMIC SCIENTISTS Ehrlich, P., Ehrlich, A. 1981; 37 (5): 26-30

  View details for Web of Science ID A1981LP54100009

• AN ECONOMIST IN WONDERLAND SOCIAL SCIENCE QUARTERLY Ehrlich, P. R. 1981; 62 (1): 44-49

  View details for Web of Science ID A1981LK49000005

• EXTINCTION OR A STRATEGY OF CONSERVATION BULLETIN OF THE ATOMIC SCIENTISTS Ehrlich, P., Ehrlich, A. 1981; 37 (6): 25-30

  View details for Web of Science ID A1981LT98600011

• THE POPULATION BIOLOGY OF CHECKERSPOT BUTTERFLIES (EUPHYDRYAS) BIOLOGISCHES ZENTRALBLATT Ehrlich, P. R., Murphy, D. D. 1981; 100 (6): 613-629

  View details for Web of Science ID A1981MT23700003

• THE COMMUNITY STRUCTURE OF CORAL-REEF FISHES AMERICAN NATURALIST ANDERSON, G. R., EHRLICH, A. H., Ehrlich, P. R., ROUGHGARDEN, J. D., Russell, B. C., TALBOT, F. H. 1981; 117 (4): 476-495

  View details for Web of Science ID A1981LK30700004

• POPULATION BIOLOGY OF THE CHECKERSPOT BUTTERFLY, EUPHYDRYAS-CHALCEDONA STRUCTURE OF THE JASPER RIDGE COLONY OECOLOGIA Brown, I. L., Ehrlich, P. R. 1980; 47 (2): 239-251

  Abstract

  Euphydryas chalcedona at Jasper Ridge consists of two independently varying major demographic units, similar in scale but not in structure to those of Euphydryas editha. In contrast, however, Jasper Ridge E. chalcedona represent just a portion of a deme-while E. editha occurs as two partially connected demes. The life history and general ecology of E. chalcedona is described and compared with those of its intensively-studied congener. Various problems of mark-release-recapture estimation of population size are discussed.

  View details for Web of Science ID A1980KU37400016

• VARIETY IS THE KEY TO LIFE TECHNOLOGY REVIEW Ehrlich, P. R. 1980; 82 (5): 58-?

  View details for Web of Science ID A1980JL53300015

• Population biology of the checkerspot butterfly, Euphydryas chalcedona structure of the Jasper Ridge colony. Oecologia Brown, I. L., Ehrlich, P. R. 1980; 47 (2): 239-251

  Abstract

  Euphydryas chalcedona at Jasper Ridge consists of two independently varying major demographic units, similar in scale but not in structure to those of Euphydryas editha. In contrast, however, Jasper Ridge E. chalcedona represent just a portion of a deme-while E. editha occurs as two partially connected demes. The life history and general ecology of E. chalcedona is described and compared with those of its intensively-studied congener. Various problems of mark-release-recapture estimation of population size are discussed.

  View details for DOI 10.1007/BF00346827

  View details for PubMedID 28309478

• POPULATION-DYNAMICS OF THE CHECKERSPOT BUTTERFLY EUPHYDRYAS-EDITHA FORTSCHRITTE DER ZOOLOGIE Singer, M. C., Ehrlich, P. R. 1979; 25 (2-3): 53-60

  View details for Web of Science ID A1979HL89700003

• WHAT HAPPENED TO THE POPULATION BOMB HUMAN NATURE Ehrlich, P. R., EHRLICH, A. H. 1979; 2 (1): 88-92

  View details for Web of Science ID A1979GC38300015

• B-CHROMOSOME VARIATION IN EUPHYDRYAS-COLON (LEPIDOPTERA, NYMPHALIDAE) CHROMOSOMA PEARSE, F. K., Ehrlich, P. R. 1979; 73 (3): 263-274

  View details for Web of Science ID A1979HK30000001

• STEADY-STATE ECONOMICS - DALY,HE HUMAN NATURE Ehrlich, P. R. 1978; 1 (8): 20-?

  View details for Web of Science ID A1978GC37500006

• POPULATION BIOLOGY OF CORAL-REEF FISHES ANNUAL REVIEW OF ECOLOGY AND SYSTEMATICS Ehrlich, P. R. 1975; 6: 211-246

  View details for Web of Science ID A1975AW70200010

• BENEFITS OF SAYING YES BULLETIN OF THE ATOMIC SCIENTISTS Ehrlich, P. R. 1975; 31 (7): 49-51

  View details for Web of Science ID A1975AP11300023

• PLANT RESOURCES AND BUTTERFLY HABITAT SELECTION ECOLOGY Sharp, M. A., Parks, D. R., Ehrlich, P. R. 1974; 55 (4): 870-875

  View details for Web of Science ID A1974U071600017

• ADULT MOVEMENTS AND POPULATION STRUCTURE IN EUPHYDRYAS-EDITHA EVOLUTION Brussard, P. F., Ehrlich, P. R., Singer, M. C. 1974; 28 (3): 408-415

  View details for Web of Science ID A1974U549500006

• THIRD-WORLD ATTITUDES ATMOSPHERIC ENVIRONMENT Ehrlich, P. R. 1974; 8 (5): 523-524

  View details for Web of Science ID A1974T250900010

• COEVOLUTION - HETEROTYPIC SCHOOLING IN CARIBBEAN REEF FISHES AMERICAN NATURALIST Ehrlich, P. R., EHRLICH, A. H. 1973; 107 (953): 157-160

  View details for Web of Science ID A1973O485200012

• ALKALOID AND PREDATION PATTERNS IN COLORADO LUPINE POPULATIONS OECOLOGIA DOLINGER, P. M., EHRLICH, P. R., FITCH, W. L., BREEDLOVE, D. E. 1973; 13 (3): 191–204

  Abstract

  Colorado populations of herbaceous perennial lupines show three distinct patterns of amounts, kinds, and individual variability of inflorescence alkaloids. These patterns, interpreted as alternative chemical defense strategies, can be related to the susceptibility of populations to attack by larvae of a small flower-feeding lycaenid butterfly, Glaucopsyche lygdamus.In situations ecologically unfavorable to G. lygdumus, lupine populations have "low" alkaloidal profiles, accumulating relatively low amounts of single, bicyclic alkaloids in their inflorescences, with little individual alkaloidal variability, Lupine populations which are quite available to G. lygdamus, on the other hand, accumulate much higher amounts of inflorescence alkaloids. Of these alkaloidally "high" populations, those which suffer only minor predation by G. lygdamus have individually variable mixtures of three or four inflorescence alkaloids, which are found to be isomers of lupanine and closely related tetracyclic compounds. In contrast, those which suffer heavy predation by G. lygdamus show a mixture of nine diverse alkaloidal components including lupanine, hydroxylupanine, and hydroxylupanine esters which is quite invariant from individual to individual.It is hypothesized that individual variability in alkaloids is an anti-specialist chemical defense mechanism. Such individual variability may be advantageous to plant populations by reducing the possibility of selection for strains of specialist herbivores capable of detoxifying or otherwise withstanding plant defensive compounds.

  View details for PubMedID 28308576

• CRYING NEED FOR QUIET CONFERENCES - PERSONAL NOTES FROM STOCKHOLM SCIENCE AND PUBLIC AFFAIRS-BULLETIN OF THE ATOMIC SCIENTISTS Ehrlich, P. R. 1972; 28 (7): 30-32

  View details for Web of Science ID A1972N422500011

• EFFECT OF CROWDING ON HUMAN TASK PERFORMANCE JOURNAL OF APPLIED SOCIAL PSYCHOLOGY Freedman, J. L., Klevansky, S., Ehrlich, P. R. 1971; 1 (1): 7-25

  View details for Web of Science ID A1971Y257800002

• POPULATION BIOLOGY OF BUTTERFLY EUPHYDRYAS EDITHA .6. PHENETICS OF JASPER RIDGE COLONY 1965-66 EVOLUTION MASON, L. G., EHRLICH, P. R., EMMEL, T. C. 1968; 22 (1): 46-&

  View details for PubMedID 28564990

• POPULATION BIOLOGY OF BUTTERFLY EUPHYDRYAS EDITHA .V. CHARACTER CLUSTERS AND ASYMMETRY EVOLUTION MASON, L. G., EHRLICH, P. R., EMMEL, T. C. 1967; 21 (1): 85-&

  View details for PubMedID 28556098

• POPULATION BIOLOGY OF BUTTERFLY EUPHYDRYAS EDITHA .3. SELECTION AND PHENETICS OF JASPER RIDGE COLONY EVOLUTION EHRLICH, P. R., MASON, L. G. 1966; 20 (2): 165-&

  View details for PubMedID 28563621

• THE POPULATION BIOLOGY OF THE BUTTERFLY, EUPHYDRYAS-EDITHA .2. THE STRUCTURE OF THE JASPER RIDGE COLONY EVOLUTION EHRLICH, P. R. 1965; 19 (3): 327–36

  View details for DOI 10.2307/2406442

  View details for Web of Science ID A1965CLA4300004

• BUTTERFLIES AND PLANTS - A STUDY IN COEVOLUTION EVOLUTION EHRLICH, P. R., RAVEN, P. H. 1964; 18 (4): 586–608

  View details for DOI 10.2307/2406212

  View details for Web of Science ID A1964CLA4000007

• SOME AXIOMS OF TAXONOMY SYSTEMATIC ZOOLOGY EHRLICH, P. R. 1964; 13 (3): 109–23

  View details for DOI 10.2307/2411485

  View details for Web of Science ID A1964WU95000001

• PATTERNS AND POPULATIONS SCIENCE EHRLICH, P. R., HOLM, R. W. 1962; 137 (3531): 652-&

  Abstract

  In summary, then, we would like to suggest that in broad investigations of the patterns of interaction and relationship among organisms the artificial and stultifying fragmentation of population biology into divisions such as taxonomy, population genetics, and ecology should be ignored. Care also should be taken to scrutinize current concepts such as "species," "niche," and "community." If some emergent patterns seem to correspond to a great degree with these concepts, then the concepts may be given operational definitions and the labels should be retained. If there is no such correspondence, then the concepts will have outlived their usefulness and should be discarded. The basic units of population biology are not communities, species, or even populations, but individual organisms (32). In populations, variation, growth, genetic equilibria, selection, behavior, and so on are not "things" but relationships. Therefore, what is of interes in population biology is the pattern in which organisms are related in space and time (33).

  View details for DOI 10.1126/science.137.3531.652

  View details for Web of Science ID A19623026C00011

  View details for PubMedID 17770944

• INTRINSIC BARRIERS TO DISPERSAL IN CHECKERSPOT BUTTERFLY SCIENCE EHRLICH, P. R. 1961; 134 (347): 108-&

  Abstract

  Capture-recapture studies revealed that the checkerspot butterfly Euphydryas editha is extraordinarily sedentary. Since no physical barriers prevent interchange between various portions of the study colony, it is concluded that intrinsic factors play the major role in limiting movement. The few available data on dispersal are discussed.

  View details for DOI 10.1126/science.134.3472.108

  View details for Web of Science ID A19612982C00034

  View details for PubMedID 17807397

• NATURAL-SELECTION IN MIDDLE ISLAND WATER SNAKES (NATRIX-SIPEDON I) EVOLUTION EHRLICH, P. R., CAMIN, J. H. 1960; 14 (1): 136

  View details for DOI 10.2307/2405932

  View details for Web of Science ID A1960XE16800016