The distribution of the X haplogroup is very intriguing too. But as far as I know the X2 haplogroup spread into America between 18000 to 11000 YBP? Only in the Caucasus region the X haplogroup arrived during the appropriate time frame, all other regions, save the Altai area were settled during or shortly after the last gacial maximum. (Reidla et al. 2003)