More Neandertal mtDNA stuff…

Has anyone read Hawk’s latest blog about Neandertal mtDNA? He answers some emailer’s questions and goes on a long explanation.

His “Drift” section has me confused. If someone could read what Hawks wrote, and then maybe explain the concept to me like I’m a college freshman who barely understands this stuff, that would be excellent. Basically, I don’t understand how his explanation shows that drift probably didn’t happen. Instead it seems like a lot of mathematical mumbo-jumbo, ending with Hawks stating that “contamination” might just be proof that neandertals and humans shared DNA. I’m concerned because I’m not even sure which part of it I find confusing: the concept of drift, the population genetics involved, what mtDNA tells us, or all three!

His other explanations make sense, if I assume his Drift-stuff is true. Please help!