Y-chromosomal Aaron - Wikipedia, the free encyclopedia
Y-chromosomal Aaron is the name given to the hypothesised most recent common ancestor of many of the patrilineal Jewish priestly caste known as Kohanim (singular "Kohen", "Cohen", or Kohane). In the Torah, this ancestor is identified as Aaron, the brother of Moses. The hypothetical most recent common ancestor was therefore jocularly dubbed "Y-chromosomal Aaron", in analogy to Y-chromosomal Adam.
The original scientific research was based on the discovery that a majority of present-day Jewish Kohanim either share, or are only one step removed from, a pattern of values for 6 Y-STR markers, which researchers named the Cohen Modal Haplotype (CMH). However it subsequently became clear that this six marker pattern was widespread in many communities where men had Y chromosomes which fell into Haplogroup J; the six-marker CMH was not specific just to Cohens, nor even just to Jews, but was a survival from the origins of Haplogroup J, about 30,000 years ago.[citation needed]
More recent research, using a larger number of Y-STR markers to gain higher resolution more specific genetic signatures, has indicated that about half of contemporary Jewish Kohanim, who share Y-chromosomal haplogroup J1c3 (also called J-P58), do indeed appear to be very closely related. A further approximately 15% of Kohanim fall into a second distinct group, sharing a different but similarly tightly related ancestry. This second group fall under haplogroup J2a (J-M410). A number of other smaller lineage groups are also observed. Only one of these haplogroups could indicate ancestry from Y-chromosomal Aaron.
Further study published in 2009 found new markers and better defined variant J1e* (now J1c3, also called J-P58*). This research demonstrates that 46.1% of Kohanim carry Y chromosomes belonging to a single paternal lineage (J-P58*) that likely originated in the Near East well before the dispersal of Jewish groups in the Diaspora. Support for a Near Eastern origin of this lineage comes from its high frequency in our sample of Bedouins, Yemenis (67%), and Jordanians (55%) and its precipitous drop in frequency as one moves away from Saudi Arabia and the Near East (Fig. 4). Moreover, there is a striking contrast between the relatively high frequency of J-58* in Jewish populations (»20%) and Kohanim (»46%) and its vanishingly low frequency in our sample of non- Jewish populations that hosted Jewish diaspora communities outside of the Near East.[6]
Thomas, et al. dated the origin of the shared DNA to approximately 3,000 years ago (with variance arising from different generation lengths). The techniques used to find Y-chromosomal Aaron were first popularized in relation to the search for the patrilineal ancestor of all contemporary living humans, Y-chromosomal Adam.
Responses
The finding led to excitement in religious circles, with some seeing it as providing some "proof" of the historical veracity of part of the Bible[7] or other religious convictions.[8] There was also criticism that the paper's evidence was being overstated.[9]
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