Jood Al Aswad

All Publications

• Physiology and climate change explain unusually high similarity across marine communities after end-Permian mass extinction. Science advances Al Aswad, J. A., Penn, J. L., Monarrez, P. M., Bazzi, M., Deutsch, C., Payne, J. L. 2025; 11 (13): eadr4199

  Abstract

  Fossil assemblages exhibit a global depletion in taxonomic distinctiveness in the aftermath of the end-Permian mass extinction (~252 million years ago), but little is known about why. Here, we examine whether biotic homogenization can be explained by tropical survivors tracking an expansion of their preferred habitat, measured in terms of the ratio of environmental oxygen supply to metabolic demand. We compare spatial similarity in community composition among marine invertebrate fossils represented by bivalve and gastropod fossils with predictions from an ecophysiological model of habitat that diagnoses areas in the ocean that can sustain the aerobic requirements of marine invertebrates. Modeled biogeographic responses to climate change yield an increase in global similarity of community composition among surviving ecophysiotypes, consistent with patterns in the fossil record and arguing for a physiological control on earliest Triassic biogeography.

  View details for DOI 10.1126/sciadv.adr4199

  View details for PubMedID 40138424

• Selectivity of mass extinctions: Patterns, processes, and future directions. Cambridge prisms. Extinction Payne, J. L., Al Aswad, J. A., Deutsch, C., Monarrez, P. M., Penn, J. L., Singh, P. 2023; 1: e12

  Abstract

  A central question in the study of mass extinction is whether these events simply intensify background extinction processes and patterns versus change the driving mechanisms and associated patterns of selectivity. Over the past two decades, aided by the development of new fossil occurrence databases, selectivity patterns associated with mass extinction have become increasingly well quantified and their differences from background patterns established. In general, differences in geographic range matter less during mass extinction than during background intervals, while differences in respiratory and circulatory anatomy that may correlate with tolerance to rapid change in oxygen availability, temperature, and pH show greater evidence of selectivity during mass extinction. The recent expansion of physiological experiments on living representatives of diverse clades and the development of simple, quantitative theories linking temperature and oxygen availability to the extent of viable habitat in the oceans have enabled the use of Earth system models to link geochemical proxy constraints on environmental change with quantitative predictions of the amount and biogeography of habitat loss. Early indications are that the interaction between physiological traits and environmental change can explain substantial proportions of observed extinction selectivity for at least some mass extinction events. A remaining challenge is quantifying the effects of primary extinction resulting from the limits of physiological tolerance versus secondary extinction resulting from the loss of taxa on which a given species depended ecologically. The calibration of physiology-based models to past extinction events will enhance their value in prediction and mitigation efforts related to the current biodiversity crisis.

  View details for DOI 10.1017/ext.2023.10

  View details for PubMedID 40078672

  View details for PubMedCentralID PMC11895734