Who am I? Genes and the problem of historical identity

Afundamental conundrum at the heart of the new genetics is the question "Who am I?" Despite what we may believe about ourselves-based on our family lore, our photographs, our documented past, or the recollections and memorabilia of our ancestors-genetics makes possible bold claims about self and family that may be at odds with these long-relied-upon artifacts of identity. When seeking historical guidance as to who we are, we can look backward in multiple ways-the matrilineal line, the patrilineal line (along which names are often, but not always, transferred), some combination of family lines (the mother's father's family line, for example), or in ways totally outside the biological family. Genetic science has emerged from the laboratory and clinic in recent years to add new complexity to this already complex process, and to revise our self knowledge.