Ok: The Human Diasporas by Luigi Luca Cavalli-Sforza and Francesco Cavalli-Sforza:
This has a somewhat different and less specific account of the separation of people. Africa split with the rest of the world 100,000 years ago, Southeast Asia and Australia split 55-60,000 years ago, Asia and Europe split 35-40,000 years ago and Northeast Asia and America split 15-35,000 years ago. The closest genetically are the last two, because mutations over time cause genetic difference. (Africans are more genetically diverse than the rest of the world combined because they've been there much longer.) Mutations are an ongoing process, 3-4 letters in the DNA structure change during every cell division. Most of them don't have any effect, though.
This book also talks about an African "Eve". This isn't the woman from the Biblical account, but simply the term for an ambiguously common ancestor. This is based on the study of mitochondrial DNA (mitochondria is passed down from the mother's side), which shows that at some point in history there was a genetic bottleneck, when a small group of people (the first group of genetically modern humans homo sapiens sapiens), all with the same mitochondria as that one "Eve", become the direct ancestors of all people. This event is generally dated at about 190,000 years ago.
Also, the only geologic evidence of any type of great flood is the forming of the Black Sea by receding glacial ice. This happened about 7000 years ago and is clearly the source of the all of the flood stories. Baucis and Philemon is the Greek mythological flood story. This, though, has nothing to do with a genetic bottleneck because it only effected people in the area of the Black Sea (the Fertile Crescent), which just so happened to contain the most influential people in history, pillaging and passing on their stories to every other culture.
