 For example, the broad geographic range of haplogroup X has been interpreted as allowing the possibility of a western Eurasian, or even a European source population for Native Americans, as in the Solutrean hypothesis, or suggesting a pre-Last Glacial Maximum migration into the Americas.The analysis of an ancient variant of haplogroup X among aboriginals of the Altai region indicates common ancestry with the European strain rather than descent from the European strain.Further division of X subclades has allowed identification of subhaplogroup X2a, which is regarded as specific to Native Americans.