Here is a Magazine Feature Story that Blaine Bettinger pointed out:
"The Ancestor Hunter" By: Michael Haederle August 31, 2009
"The University of Arizona's Michael Hammer is using advanced DNA techniques to figure out where we came from. Which, apparently, is not just one place, or even one species".http://www.miller-mccune.com/science_environment/the-ancestor-hunter-1372
Here is one of the scientific articles:
Genetics, Vol. 178, 427-437, January 2008, Copyright © 2008
"Testing for Archaic Hominin Admixture on the X Chromosome: Model Likelihoods for the Modern Human RRM2P4 Region From Summaries of Genealogical Topology Under the Structured Coalescent
Murray P. Cox, Fernando L. Mendez, Tatiana M. Karafet, Maya Metni Pilkington, Sarah B. Kingan, Giovanni Destro-Bisol, Beverly I. Strassmann and Michael F. Hammer http://www.genetics.org/cgi/reprint/178/1/427
This paper is worth a discussion here...