Y chromosome study sheds light on Athapaskan migration to so...( A lot of the Y chromosomes have been...)

"A lot of the Y chromosomes have been replaced by European males," he said.

Malhi and his colleagues looked at specific regions on the Y chromosome that can vary from person to person. Tiny differences in the sequence of nucleotides that spell out the genetic code can be used to determine whether and how closely individuals are related to one another. Those who share many of these genetic signatures are more likely to share a recent common ancestor than those who don't.

The researchers analyzed 724 Y chromosomes from 26 native populations in North America. By including groups from across the continent (they studied tribes from Alaska to the Yucatan Peninsula and eastward to Hudson Bay and southeast U.S.), the researchers were able to analyze genetic differences among many native groups and to get an idea of the degree of European male infiltration into the native gene pool.

Consistent with a previous study of native North American mitochondrial DNA (also led by Malhi), the new analysis found a pattern that indicates that a small group of subarctic Athapaskans miYgrated to the Southwest. This pattern is reflected in the fact that many Apacheans carry the genetic signature of a small subset of subarctic Athapaskans.

These findings also affirm an earlier study of variants of a particular protein, albumin, in different native groups. That study showed that while many Apacheans carried an albumin variant common among natives in the Southwest and Mesoamerica, some Apacheans were the only ones to carry a variant that also occurs in subarctic populations.

Other patterns emerged from the Y chromosome analysis. One genetic signature associated with European males was detected in native males throughout North America, but was found at the highest frequency in groups living nearest to Hudson Bay, where trade between Europeans and the region's indigenous peoples was established in the early 17th century.

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