Talk:Controversies in Science/Was there a mitochondrial Eve?/a critique of Human demographic history: refining the recent African origin model

There can only be a small amount of difference between two species in order for them to be able to produce fertile offspring. For example, a horse and a donkey can be bred to produce a mule, but mules are infertile. Therefore, limited human diversity is only proof that humans are able to reproduce, not that we cannot have descended from slightly different species thousands of years ago. PolkaDots576 (talk) 02:54, 28 March 2012 (UTC)