Genomics of Extinction

Abstract

Many species went extinct during the Late Pleistocene, including a large proportion of the Earth’s megafauna. Recent research on Pleistocene extinctions has started to reveal that species responded individualistically to environmental fluctu- ations and human interference. Through paleogenomics, it is now possible to study the extinction process in more detail, which could help disentangle why some species went extinct while others did not. Several species seem to have gone through a sudden decline right before extinction, whereas others reached the point of extinction via a gradual decline. In addition, some species experienced an initial severe bottleneck but survived for thousands of years more at reduced numbers before their final extinction. The use of temporally spaced complete genomes allows for a more direct examination of changes in genomic parameters through time, such as declines in standing genetic variation and accumulation of deleterious mutations, as a consequence of these pre-extinction processes. Additionally, the increasing access to complete ancient genomes will in the future allow researchers to investi- gate whether species were capable of adapting to environmental changes as well as the small population size that they were subject to prior to the extinction.