Beyond the genome : did Adam meet Eve?.

What do our genes reveal about early history? By examining the Y chromosome, a family tree of males can be established. It can be good evidence of illegitimacy. An examination of the descendants of President Thomas Jefferson, from his possible affair with black slave Sally Hemmings, shows which men really did have Jefferson genes. Mark Thomas is mapping out the distribution of the y chromosome in English/Welsh/Irish populations, and has found a significant difference at the Welsh border, indicating the extent of Anglo-Saxon invasion. Peter Underhill and David Goldstein consider the common male ancestor in Africa. Women tend to move longer distances over time, so their chromosomes are more variable.