Aaron of the Y chromosome

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The Y-chromosome Aaron is believed to be the earliest ancestor of the Kohanim , a patrilineal priestly caste within Judaism and a subgroup of the Levites . In the Jewish Tanakh this ancestor is identified with Aaron , the brother of Moses .

The techniques used to find the Y-chromosome Aaron were initially popularized primarily in relation to finding the paternal ancestor of all humans , the Y-chromosome Adam .

background

Genetically , every healthy person has 46 chromosomes , 23 from each parent. Two chromosomes, the X chromosome and the Y chromosome , determine the gender. Women have two X chromosomes, one from the mother and one from the father. Males have one X chromosome from their mother and one Y chromosome from their father.

Men with a common paternal ancestor must therefore also have a common Y chromosome that only shows deviations with regard to certain mutations . Mutations of the Y chromosome occur at a relatively constant rate, which allows scientists to calculate up to which generation the carriers of the similar Y chromosomes had a common ancestor (see molecular clock ).

Another type of DNA, mitochondrial DNA (mtDNA), is not found on a chromosome, but is transferred from mother to child via the cytoplasm of the egg cell. The mtDNA comes almost completely from the mother and also remains unchanged - apart from accumulated mutations.

The hypothesis

Belonging to Judaism traditionally runs through the maternal line. Belonging to the specific group of Jewish priests ( Kohanim ) is defined patrilinearly . The Kohanim claim to be the direct descendants of Aaron, the Moses brother. Since male children always receive the Y chromosome from the father, it can be assumed that all Kohanim would have to have the same Y chromosome in common, apart from mutations since Aaron.

Test the hypothesis

This hypothesis was first tested by Karl Skorecki and co-workers in Haifa , Israel . In 1997 they discovered a conspicuously high proportion of certain Y chromosome markers among the Kohanim, which is considered to confirm the hypothesis. Other studies supported the discovery and dated the origin of the common DNA to around 3,000 years ago (with variations due to different generations). This led to the development of the Cohen Modal Haplotype (CMH), a set of Y-chromosome ( DNA Y-chromosome segment , DYS) markers that could be traced back to the biblical Aaron.

Cohen Modal Haplotype

The Cohen Modal Haplotype looks like this:

DYS 19 / DYS394 = 14 

DYS388 = 16
DYS390 = 23
DYS391 = 10
DYS392 = 11
DYS393 = 12

The Cohen Modal Haplotype belongs to haplogroup J (Y-DNA) .

Criticism and reply

The discovery caused great excitement in religious circles, where they were celebrating a kind of “proof” of the historical truth of the Bible; on the other hand, it also triggered criticism.

Other carriers of DNA

There are also non-Jewish populations in which the Cohen Modal Haplotype has been found in conspicuous numbers. For example with Italians. A conceivable connection is the historically documented deportation of Jewish slaves to Rome , or today's Italy , especially in connection with the construction of the Colosseum . The Lemba , native to South Africa and Zimbabwe, trace their origins back to Judaism. The genetic findings, especially in the Lemba clan, confirm this tradition. The CMH also occurs in some groups of Kurds .

Levi of the Y chromosome?

While the Kohanim are believed to be patrilineal descendants of the Moses brother Aaron (Aaronites), the Levites (the next level of the Jewish priesthood) are traditionally considered to be patrilineal descendants of Levi , the son of Jacob and great-grandfather of Aaron. Consequently, the Levites would also have to share a common Y chromosome DNA.

A study of men who counted themselves among the Levites found clear markers in large numbers as an indication that many non-Aaronites are to be ascribed to the Levitic origin. In contemporary Eastern European ( Ashkenazi ) Jews, a certain marker points to over 50 percent of the Levites, i.e. to a common male ancestor within the last 2000 years, and also to a high proportion of Levites within the Ashkenazim group. However, this marker belongs to the haplogroup R1a1-Z93, a special Oriental-Asian branch to which the Eastern European Jews (Ashkenazim), including the German Jews, also belong. In the Orient, the haplogroup R1a1-Z93 (among others) also occurs in Iranians, Persians, Pashtuns, Kurds, Arabs as well as in the Caucasus and Anatolia, roughly speaking in Orientals of Indo-Aryan origin. There is also an increased proportion of Indo-Aryan origin in the Indian Brahmin caste.

The haplogroup R1a is associated with the migratory movement of the Indo-Europeans to the east and is directly related to the spread of corded ceramics and the spherical amphora culture , in short from the Rhine to the Ural Mountains with an extension to Asia. The connection between the European and the Oriental-Asian haplogroup and their separation has not yet been clarified.

See also

literature

Web links

Individual evidence

  1. ^ MG Thomas, K. Skorecki u. a .: Origins of Old Testament priests. In: Nature. Volume 394, No. 6689, July 1998, ISSN  0028-0836 , doi: 10.1038 / 28083 , PMID 9671297 , pp. 138-140 (English).
  2. ↑ Rabbi Yaakov Kleiman: The Cohanim - DNA Connection. In: Aish.com: Your Life, Your Judaism. Israel, January 12, 2000, accessed February 10, 2014 .
  3. ^ Robert Rosenberg: Doctor finds fault in the contentions that the "Cohen modal haplotype" designates Israelites and that most Jewish priests have a common ancestor. In: Ariga. Own website, February 27, 2001, archived from the original on September 9, 2009 ; accessed on February 10, 2014 .
  4. ^ MG Thomas, T. Parfitt et al. a .: Y chromosomes traveling south: the cohen modal haplotype and the origins of the Lemba - the "Black Jews of Southern Africa". In: American Journal of Human Genetics . Volume 66, No. 2, February 2000, ISSN  0002-9297 , doi: 10.1086 / 302749 , PMID 10677325 , PMC 1288118 (free full text), pp. 674-686 (English).
  5. ^ DM Behar, MG Thomas u. a .: Multiple origins of Ashkenazi Levites: Y chromosome evidence for both Near Eastern and European ancestries. In: American Journal of Human Genetics . Volume 73, No. 4, October 2003, ISSN  0002-9297 , doi: 10.1086 / 378506 , PMID 13680527 , PMC 1180600 (free full text), pp. 768-779 (English).