A rapid loss of stripes: the evolutionary history of the extinct quagga

摘要

Twenty years ago, the field of ancient DNA was launched with the publication of two short mitochondrial (mt) DNA sequences from a single quagga (Equus quagga) museum skin, an extinct South African equid ( Nature >312, 282–284). This was the first extinct species from which genetic information was retrieved. The DNA sequences of the quagga showed that it was more closely related to zebras than to horses. However, quagga evolutionary history is far from clear. We have isolated DNA from eight quaggas and a plains zebra (subspecies or phenotype Equus burchelli burchelli). We show that the quagga displayed little genetic diversity and very recently diverged from the plains zebra, probably during the penultimate glacial maximum. This emphasizes the importance of Pleistocene climate changes for phylogeographic patterns in African as well as Holarctic fauna.