I study the historical ecology and evolution of marine ecosystems and the ways that human activities have affected their biodiversity and function. I am currently working on a synthesis of my last thirty five years of paleobiological research on the evolution of Caribbean marine communities as affected by their isolation from the Pacific Ocean due to the uplift of the Isthmus of Panama, with particular emphasis on coral reefs and associated seafloor biota. Another major focus is the decline of coral reefs due to exploitation, pollution, and climate change and the potential for reef restoration. I am also working on a new book on the historical ecology of the global tropics.