I was recently checking my favorite website, topdocumentaryfilms.com, and I came across Spencer Wells' new documentary titled Tree of Life, where just as Journey of Man, he (in combination with National Geographic & IBM) traces the genetic code of diverse populations.
This time, he goes to Queens N.Y. where you find the most diverse population. Through DNA analysis, they are able to trace the genetic history of the origins of various people. As fascinating as this sounds, it raises a lot of questions to me. What assumptions are being made and what do they leave behind?
Check out the video http://topdocumentaryfilms.com/human-family-tree/
The San Diego Museum of Man has an exhibit about this and also the American Anthro Assoc. recent (amazing!!) Race exhibit. You should take some time to go visit these.