Rachel Carson College Faculty Fellows

Summary of Expertise

Isotope biogeochemistry, paleobiology, ecology and evolution

Research Interests

Paul's research focuses on vertebrate paleoecology and evolution, which he places in environmental context through reconstruction of ancient ecosystems and climates. His work often includes biogeochemical analysis of animal tissues (teeth, bones, fur, skin, etc.) or environmental samples (soil minerals, fossil plants, etc.).

In recent years, Paul has worked in four broad areas. First, he has studied environmental change over the Cenozoic (the last 65 million years). He continues to explore the chronology and ecological consequences of the Paleocene-Eocene boundary thermal maximim (PETM) and other climatic events in the early Cenozoic. With his graduate students, he has reconstructed the topographic history of the western United States. Finally, with graduate students and other colleagues, he is reconstructing Holocene oceanographic changes along the California coast through biogeochemical records from mollusk shells.

A second major focus has been reconstruction of the paleoecology (e.g., diet, habitat preference, migratory behavior, etc.) of different groups of vertebrates. In some cases, Paul and his students have focused on evolutionary ecology, for example investigating the evolution of salt-water tolerance in crocodiles. In other cases, they've worked at an ecosystem scale, exploring how different members of a community exploit food resources or space. Much of this latter work has focused on Pleistocene communities. Paul is trying to understand the ecological factors that may have contributed to the collapse of these systems in the face of human exploitation over the past 40,000 years, as well as how these communities "worked" prior to their collapse.

An important related thread has been Conservation Paleobiology, using fossils from extant species to glean information of use for conservation planning. He and his students have a number of ongoing projects on seals and sea lions, lemurs, condors, and other species. They've discovered that some species behaved very differently in the recent past. They've tried to understand why behaviors have changed, and whether or not species might be able to "recover" their lost ecological potential. A major ongoing project on this front is exploring how environmental change over the past 10,000 years drove population level changes in the seals in the Ross Sea region of Antarctica.

Finally, a great deal of work in Paul's lab is now devoted to ecological studies of modern animals. Ecologists studying modern species have discovered that the biogeochemical methods developed to study ancient animals can provide insights into the ecology of living species, especially ones with behaviors or habitats that make them hard to observe or track (e.g., migratory birds, marine mammals, deep forest species). Beginning with Paul's early work on the ecology of living elephants, this work has expanded greatly (especially in the work of his graduate students and other colleagues) to include African carnivores, lemurs, sharks, and many different kinds of seals and sea lions. A major ongoing project on this front is a collaborative study with researcher Iliana Ruiz-Cooley and Ocean Sciences faculty member Matt McCarthy on the trophic level of sperm whales and how it has changed over the past century in response to environmental and anthropogenic forces.

Biography, Education and Training

B.A., University of Rochester
M.S., Ph.D., University of Michigan

Postdoc., National Museum of National History, Smithsonian Institution

Postdoc., Geophysical Laboratory, Carnegie Institution of Science

Honors, Awards and Grants

Charles Schuchert Award from the Paleontological Society, 1998
Fellow, Paleontological Society, 2005
Fellow, Geological Society of America, 2006
Fellow, California Academy of Sciences, 2013

Selected Publications

Publications

Teaching Interests

History of Life, Isotopes in Ecology and Paleoecology