Another thing of great interest to me is the genetic make up of various populations around the world and also how the story of the migrations of early humans can be discovered from modern DNA. The book that got me started thinking about all this was Spencer Wells’ book the Journey of Man and then many of the Bryan Sykes books starting with The Seven Daughters of Eve: The Science That Reveals Our Genetic Ancestry and most recently Saxons, Vikings, and Celts: The Genetic Roots of Britain and Ireland and DNA USA: A Genetic Portrait of America

I have put links to family tree DNA pages on various populations’ genetics in the menu dropdown from this item above. There is also a good article at wikepedia about the genetic composition of Europeans.