Biotic and Abiotic Controls on the Phanerozoic History of Marine Animal Biodiversity

During the past 541 million years, marine animals underwent three intervals of diversification (early Cambrian, Ordovician, Cretaceous-Cenozoic) separated by nondirectional fluctuation, suggesting diversity-dependent dynamics with the equilibrium diversity shifting through time. Changes in factors such as shallow-marine habitat area and climate appear to have modulated the nondirectional fluctuations. Directional increases in diversity are best explained by evolutionary innovations in marine animals and primary producers coupled with stepwise increases in the availability of food and oxygen. Increasing intensity of biotic interactions such as predation and disturbance may have led to positive feedbacks on diversification as ecosystems became more complex. Important areas for further research include improving the geographic coverage and temporal resolution of paleontological data sets, as well as deepening our understanding of Earth system evolution and the physiological and ecological traits that modulated organismal responses to environmental change.

Automated summary

Research indicates that marine animals underwent three distinct intervals of diversification over the past 541 million years, influenced by diversity-dependent dynamics with the equilibrium diversity shifting through time. The directional increases in diversity are attributed to evolutionary innovations in marine animals and primary producers, along with stepwise increases in food and oxygen availability. Additionally, increasing intensity of biotic interactions such as predation and disturbance may have led to positive feedbacks on diversification as ecosystems became more complex. Further research is needed to improve geographic coverage and temporal resolution of paleontological data sets, as well as deepen understanding of Earth system evolution and organismal responses to environmental change.