The Geological Consequences of Evolution

Abstract

Geobiologists seek to understand the role of organisms in the Earth system. By extension, one can ask how evolutionary innovations and, more generally, the population genetic processes that mediate evolution have influenced the Earth’s surface through time. The example of oxygenic photosynthesis and the redox history of atmospheres and oceans illustrates the complex relationship between evolution and environmental change. Biological innovations determine the dimensions of biological participation in the Earth system, but by themselves they seldom generate lasting environmental change. More commonly, environments change when physical drivers exceed the limited environmental buffering capacity conferred by population genetics and nutritional codependence. Environmental change, in turn, feeds back on biology, creating new opportunities for evolutionary innovation.