Hello the Dude,
You are aware, I presume, that David Stewart MD claims that a close examination "demonstrates that modern DNA evidence in no way disproves the traditional LDS belief that Book of Mormon peoples represent the principal ancestors of the American Indians."
I assumed that Dr. Stewart suggested something along those lines. Unlike you, however, I’m not qualified to offer any sort of critique—I had a hard time just putting up with my Brother-in-Law over the holidays who is pursuing a PhD at Oxford in Stem Cell Research—actually, come to think of it, that may have been a bit more interesting.
For years, I’ve believed that the Book of Mormon story involved a very small family group that interacted with a much more dominate early American culture, so I have no vestment either way in the DNA issue.
Given my respect for your knowledge, I’ll simply take your word on it that DNA analysis stomps out any chance for the Hemispheric model.
Truth be told, I would just as soon that it did.