7 - 2 million years ago: each species adapting to local ecological conditions.
3 - 2 million years ago: large brain/body ratio
1.5 million years ago: several species of the Homo genus (e.g. Homo erectus)
130,000-100,000 years ago: early race of modern humans (Homo sapiens)
100,000-40,000 years ago: the contemporary "race" of modern
humans first appear, probably in southern Africa.
In the brief space of 40,000 years -- far too fast for biological evolution -- humans spread to every corner of the planet. What was the consequence for our genetics?