Determining the drivers of extinction across space and time

Extinction has occurred continuously over the history of life on Earth. This long record of species’ loss means the biodiversity existing on Earth today is only a small fraction of the biodiversity that has ever existed. To understand the dynamics of extinction and the mechanisms that ultimately generate biodiversity, we must look to the fossil record. Fossil data allow us to identify the factors that have been associated with extinction risk over the history of life on Earth and quantify their relative importance. Despite foundational research in this area, there is still little understanding of the drivers of extinction across timescales. This fundamental knowledge gap limits our understanding of evolutionary mechanisms and hinders efforts to conserve biodiversity.In EXTINCT, I will close this gap by developing novel methods to determine controls on extinction for marine invertebrates across spatial and temporal scales. On long timescales, I will test the importance of environmental stressors in driving species-level extinction, using new paleoenvironmental reconstructions. On shorter timescales, I will examine population, rather than species-level, dynamics to test whether local extinction is prompted by similar environmental stressors across a species’ geographic range and through time. On human timescales, I will determine the species most vulnerable to extinction today and under future anthropogenic climate change scenarios. Risk estimates will be based on the paleontological models, which will be fed into IUCN Red List assessments of extinction vulnerability, providing conservation insight. The breakthroughs enabled by this research will lead to a step change in our understanding of the controls on extinction, which will directly impact modern biodiversity. The proposed research cuts across disciplines to address one of the most fundamental questions in the biological and Earth sciences: what regulates patterns of biodiversity?