I am a quantitative evolutionary biologist interested in the mechanisms driving macroevolutionary patterns of trait evolution. Currently, I am investigating the impact of climate on anuran breeding phenology, and the underlying genetic diversity and gene expression patterns of aquaporin proteins which might have resulted in the diverse breeding strategies we see today in anurans.

Stanford Advisors

2023-24 Courses

All Publications

  • Water availability and temperature as modifiers of evaporative water loss in tropical frogs. Integrative and comparative biology Juarez, B. H., Quintanilla-Salinas, I., Lacey, M. P., O'Connell, L. A. 2024


    Water plays a notable role in the ecology of most terrestrial organisms due to the risks associated with water loss. Specifically, water loss in terrestrial animals happens through evaporation across respiratory tissues or epidermis. Amphibians are ideal systems for studying how abiotic factors impact water loss since their bodies often respond quickly to environmental changes. While the effect of temperature on water loss is well known across many taxa, we are still learning how temperature in combination with humidity or water availability affects water loss. Here, we tested how standing water sources (availability) and temperature (26 and 36°C) together affect water loss in anuran amphibians using a Bayesian framework. We also present a conceptual model for considering how water availability and temperature may interact, resulting in body mass changes. After accounting for phylogenetic and time autocorrelation, we determined how different variables (water loss and uptake rates, temperature, and body size) affect body mass in three species of tropical frogs (Rhinella marina, Phyllobates terribilis, and Xenopus tropicalis). We found that all variables impacted body mass changes with greater similarities between P. terribilis and X. tropicalis, but only temperature showed a notable effect in P. terribilis. Furthermore, we describe how the behavior of P. terribilis might affect its water budget. This study shows how organisms might manage water budgets across different environments and is important for developing our models of evaporative water loss and species distributions.

    View details for DOI 10.1093/icb/icae057

    View details for PubMedID 38839599

  • Pavement ant extract is a chemotaxis repellent for C. elegans. microPublication biology Lopez, J. S., Ali, S., Asher, M., Benjamin, C. A., Brennan, R. T., Burke, M. L., Civantos, J. M., DeJesus, E. A., Geller, A., Guo, M. Y., Haase Cox, S. K., Johannsen, J. M., Kang, J. S., Konsker, H. B., Liu, B. C., Oakes, K. G., Park, H. I., Perez, D. R., Sajjadian, A. M., Torio Salem, M., Sato, J., Zeng, A. I., Juarez, B. H., Gonzalez, M., Morales, G., Bradon, N., Fiocca, K., Pamplona Barbosa, M. M., O'Connell, L. A. 2024; 2024


    Ant behavior relies on a collection of natural products, from following trail pheromones during foraging to warding off potential predators. How nervous systems sense these compounds to initiate a behavioral response remains unclear. Here, we used Caenorhabditis elegans chemotaxis assays to investigate how ant compounds are detected by heterospecific nervous systems. We found that C. elegans avoid extracts of the pavement ant ( Tetramorium immigrans ) and either osm-9 or tax-4 ion channels are required for this response. These experiments were conducted in an undergraduate laboratory course, demonstrating that new insights into interspecies interactions can be generated through genuine research experiences in a classroom setting.

    View details for DOI 10.17912/micropub.biology.001146

    View details for PubMedID 38596360

    View details for PubMedCentralID PMC11002644

  • Ecology, sexual dimorphism, and jumping evolution in anurans. Journal of evolutionary biology Juarez, B. H., Moen, D. S., Adams, D. C. 2023; 36 (5): 829-841


    Sexual dimorphism (SD) is a common feature of animals, and selection for sexually dimorphic traits may affect both functional morphological traits and organismal performance. Trait evolution through natural selection can also vary across environments. However, whether the evolution of organismal performance is distinct between the sexes is rarely tested in a phylogenetic comparative context. Anurans commonly exhibit sexual size dimorphism, which may affect jumping performance given the effects of body size on locomotion. They also live in a wide variety of microhabitats. Yet the relationships among dimorphism, performance, and ecology remain underexamined in anurans. Here, we explore relationships between microhabitat use, body size, and jumping performance in males and females to determine the drivers of dimorphic patterns in jumping performance. Using methods for predicting jumping performance through anatomical measurements, we describe how fecundity selection and natural selection associated with body size and microhabitat have likely shaped female jumping performance. We found that the magnitude of sexual size dimorphism (where females are about 14% larger than males) was much lower than dimorphism in muscle volume, where females had 42% more muscle than males (after accounting for body size). Despite these sometimes-large averages, phylogenetic t-tests failed to show the statistical significance of SD for any variable, indicating sexually dimorphic species tend to be closely related. While SD of jumping performance did not vary among microhabitats, we found female jumping velocity and energy differed across microhabitats. Overall, our findings indicate that differences in sex-specific reproductive roles, size, jumping-related morphology, and performance are all important determinants in how selection has led to the incredible ecophenotypic diversity of anurans.

    View details for DOI 10.1111/jeb.14171

    View details for PubMedID 37129372

  • Evolutionary allometry of sexual dimorphism of jumping performance in anurans (Sept, 10.1007/s10682-021-10132-x, 2021) EVOLUTIONARY ECOLOGY Juarez, B. H., Adams, D. C. 2021
  • Evolutionary allometry of sexual dimorphism of jumping performance in anurans EVOLUTIONARY ECOLOGY Juarez, B. H., Adams, D. C. 2021