Saturday, July 10, 2010

REALLY ANCIENT ANCESTORS: THE " X" CHROMOSOME

So why do separate analyses for the "Y" and the "X" chromosome?  The analysis is a bit different because it looks at mitochondrial DNA (mtDNA) instead of markers along the an entire chromosome.  mtDNA does not combine at conception so it shows up in pretty much the identical form throughout the maternal line, exactly the same signature for siblings and all those tracing back mother-to-mother through many many generations.  Once again, the mtDNA analysis is useful for tracing ancient migration patterns.  In the near term, it is most useful for eliminating possible genetic relationships because, in the absence of a perfect match, no relationship exists.

The description of the maternal haplogroup is very general.  In this case, the K group also called by the catchy moniker of The Ice Immigrants, derives from a population that migrated from the Middlel East about 50,000 years ago to Europe. Naturally enough, the K haplogroup shows up in "notable rates" among the Druze, "a small and distinct religious community mainly in Lebanon and Israel."  But 10% of Kurds, Palestinians and Yeminites also belong to the K group.  Current Basques do not belong to K, but Basque remains froma few thousand years ago have large numbers.  Notable rates of K show up among Ashkenazi Jews with 20% of current day Ashkenazis in the subgroup K1a1b1a.  No, you did not read kabala.  Those are number one's, not lower case L's.  Hmmm.  Maybe some numerologist made up the subgroup label.

Finally, a 5,300-year-old man (not Sid Ceasar) whose remains were found frozen and well preserved in the Alps near the Austrian-Italian border.  You guessed it -- K.

The generality of the information makes this more like astrology than the connect-the-dot specificity of old fashioned genealogy.  One tends to identify with the part of the group that fits with a current perception of self, a club that would be worth joining. 







No comments: