Abe - Thanks for the references, as I was unaware of the more northern glyphs. Unfortunately, I have not had the time to pull up photos. Studying the construction elements could be most insightful. As to the Paabo site, well, I can't really put a great deal of faith in a "Fine Artist" of natural subject matter. If time allows, I will attempt to evaluate his material.
As to the genetic mapping, I would be inclined to consider the second of the two to be the most consistent with other supporting data. The most current information that I have available would tend to indicate at least three immigrations amongst the A,B,C/D haplogroups. The X haplogroup, particularly X2a1b is a relatively new element in the puzzle. While I may have my own personal thoughts, the truth is that the jury is still out on this one. Also, as I have noted under other headings, there is evidence for at least one other gene pool that appears to have suffered extinction.
Cormac - As always, I personally appreciate you taking the time to present this data. May others take note. What many of the individuals in the field are presently attempting to reconcile is the genetic/linguistic/archaeological/forensic/climatological evidence. As you have noted, there is a bit of leeway in regards to the fine-line definition of genetic divergence.
All factors taken into account, a time frame of circa 20,000 to 25,000 (in regards to human habitation of the Americas) may not be too out of line.
Much appreciated Swede. As the knowledge garnered through genetics is accumulating by leaps and bounds, it pays to use the most recent information one can.
I'm hesitant to go as far as your 20,000 to 25,000 BP dating, just yet, for anything other than Alaska and Northern Canada. That may change in time, but currently I don't believe it's applicable to the lower 48 States, Central or South America.