Environmental change, genetics and speciation

Environmental change is among the key factors that is thought to have highly affected the evolutionary course of many lineages by causing speciation, extinction and species turnover. A recent publication on PLOSone about Chacma baboons from South Africa shows that the geographic structure and demography inferred from mtDNA matches what’s expected from phylogentic and climatic studies indicating that changing climatic condition in the Pleistocene had indeed affected the demography and distribution of the species. The study reports that two marker regions in the mtDNA derived from fecal samples show the Chacma baboons diverged into two distinct mitochondrial clades around 1.9-1.6Ma, a time period, which coincides with a major shift to aridity.