This is an explanation of the latest findings on how and when people colonized the world. It's interesting stuff, and a lot was new to me.
However, the author doesn't really do it justice. The book has more detail on various genetic markers than I think necessary for a lay audience. Certainly I found that the level of detail detracted from the central findings rather than illustrating them. He also uses the terms 'son' and 'daughter', as well as names (Cain, Abel, Seth, Krishna), when discussing these genetic markers. I am pretty sure that what he means here is that these 'sons' and 'daughters' are descendant lineages from common ancestors. However, the metaphor is pushed pretty hard and sometimes it appears that he might be talking about literal parent-child relationships.
So, interesting but a bit difficult in places. Worth reading if the topic is of interest.