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Methusalem
06-28-2013, 08:42 AM
By Razib Khan | January 10, 2011 2:04 pm


http://blogs.discovermagazine.com/gnxp/files/2011/01/LocationEthiopia-copy.png

In the open thread someone asked: ďAny recent stuff on the genetics of Ethiopians.Ē That prompted me to look around, because Iím curious too. Poking around Wikipedia I couldnít find anything recent. A lot of the studies are older uniparental lineage based works (NRY and mtDNA). Ethiopia is interesting because unlike almost all other Sub-Saharan African nations it has a long written history. Culturally and linguistically it has both Sub-Saharan African, and non-Sub-Saharan African, affinities. The languages of highland Ethiopia are clearly Semitic. Those of lowland Ethiopia are Cushitic, a branch of the broader Afro-Asiatic language family concentrated around the Horn of Africa (Somali is a Cushitic language, though most Ethiopian nationals who speak a Cushitic dialect are of the Oromo group).

From a human evolutionary genetic perspective, Ethiopia also has specific interest. It is likely that the main recent pulse of humans Out of Africa traversed this region. Additionally, there is some evidence of deep time connections between the groups ancestral to Ethiopians and the Khoisan of southern Africa. It may be that Ethiopians and Khoisan are reservoirs of ancient genetic variation in Sub-Saharan Africa which as been overlain by Bantu in most other regions outside of West Africa. Finally, Ethiopians are known to have high altitude adaptations. This could be due to long term residence in the region, or, assimilation of favorable alleles from the long term residents by later populations.

Fortunately we can get a sense of the genetic affinities of Ethiopians thanks to a paper published last spring, The genome-wide structure of the Jewish people. The focus was clearly on Jews, but they surveyed Amhara & Tigray (Semitic speaking highlanders), Ethiopian Jews (similar ethnically to the Amhara & Tigray, but religiously non-Christian), and Oromo. In the PCA the Oromo and Semitic speaking populations are pretty obviously distinct clusters.

http://blogs.discovermagazine.com/gnxp/files/2011/01/ethipca.png


This just means that when you take worldwide genetic variation, and pull out the biggest independent dimensions, and then visualize individuals on the two largest dimensions in terms of how they explain variance, the Oromo and other Ethiopians donít really intersect. Interestingly the Amhara and Tigray are almost indistinguishable, but the Ethiopian Jews are in their own cluster. There are, for the record, 7 Oromo, 7 Amhara, 5 Tigray, and 13 Ethiopian Jews in the sample.

Now letís look at the genetic variation in ADMIXTURE. Remember this assigns the genomes of individuals in proportions to K ancestral units. As an example, if you had African Americans, Yoruba, and White Americans, in a total pool, and did K = 2, you might have a tendency where Yoruba and White Americans are in two totally different ancestral populations of K, while African Americans are 80% in one ancestry and 20% in another. The interpretation of this is straightforward, but when it comes to populations whose backgrounds we donít know as well, one should be careful. The selection of a particular value for K is going to be really important, and we shouldnít confuse the method from the reality which the method is trying to plumb.

First, K = 8 from Behar et al. Iíve reedited to highlight populations which might inform the variation of Ethiopians.

http://blogs.discovermagazine.com/gnxp/files/2011/01/ethio1.png

Now letís look at a series of Kís. Note the changes.

http://blogs.discovermagazine.com/gnxp/files/2011/01/ethio2.png

Luckily for us, we donít need to stop here. Dienekes included Beharís Ethiopians (non-Jews) for Dodecad. Additionally, he included the Masai population from the HapMap. This turns out to be important because he found that Ethiopian Sub-Saharan ancestry is similar to that of the Masai, not the other African groups.

http://blogs.discovermagazine.com/gnxp/files/2011/01/ethioDOD.png

Dienekes also provided individual outputs. Iíve stitched together Ethiopians with Egyptians and Saudis. The color coding is the same as above.

http://blogs.discovermagazine.com/gnxp/files/2011/01/ethioDOD2.png

You should be able to tell where the three groups start and stop pretty easily. Iím 99% sure that the six individuals with more East African and less Southwest Asian ancestry are all Oromo. Ethiopians, in particular highland Ethiopians, seem to me likely an ancient stabilized hybrid population between a population from Arabia, and a local Sub-Saharan population. This population seems unlikely to have been related to the peoples of West-Central Africa, who are associated with the Bantus across eastern and southern Africa. The Bantu agricultural toolkit runs into ecological constraints in various regions, and it is in those regions that non-Bantu populations have persisted. Ethiopia, with its unique climate and topography, naturally remains non-Bantu (as well as the Horn of Africa as a whole). The possible connections between Khoisan and Ethiopia may be a function of the fact that these areas harbor genetic variants which have disappeared in the intervening regions because of the Bantu expansion. I have a hard time accepting that the Bantu expansion was particular eliminationist, but I am starting to suspect that outside of Ethiopia population densities were very, very, low.

The antiquity of this ancient hybridization event to me is attested by the fact that Ethiopians lack any of the other Middle Eastern components besides the one modal in Saudi Arabia. There is a great deal of intra-population variance in the Saudi data set. Why? Part of this must be the slave trade, as well as pilgrims who remained in places like Mecca. But, I think part of the untold story here is that there may have been a larger genetic impact on Arabia after the rise of Islam from the Levant than vice versa! Probably the gene flow precedes Islam, as Arabia was hooked into worldwide trade and population movements, which Ethiopia was relatively insulated from. The Saudi data set has several people who are ďpureĒ Southwest Asian, but also several who have a great deal of West Asian + South European. These seem likely to be people who have some background in the Fertile Crescent.

Source:

http://blogs.discovermagazine.com/gnxp/2011/01/the-genetic-affinities-of-ethiopians/#.Uc1Ldvm-2So

Anglojew
06-28-2013, 08:48 AM
Interesting.

I've read most Ethiopians were jewish before converting to other religions.

Methusalem
06-28-2013, 08:54 AM
Interesting.

I've read most Ethiopians were jewish before converting to other religions.

There is an Ethiopian Jewish minority called Beta Israel. But they are probably converts:


DNA evidence
A 1999 study by Lucotte and Smets studied the DNA of 38 unrelated Beta Israel males living in Israel and 104 Ethiopians living in regions located north of Addis Ababa. It concluded that "the distinctiveness of the Y-chromosome haplotype distribution of the Beta-Israel from conventional Jewish populations and their relatively greater similarity in haplotype profile to non-Jewish Ethiopians are consistent with the view that the Beta Israel people descended from ancient inhabitants of Ethiopia and not the Levant."[53][54] This study confirmed the findings of a 1991 study by Zoossmann-Disken et al.[55] Similarly, a 2000 study by Hammer et al. of Y-chromosome biallelic haplotypes of Jewish and non-Jewish groups suggested that "paternal gene pools of Jewish communities from Europe, North Africa, and the Middle East descended from a common Middle Eastern ancestral population", with the exception of the Beta Israel, who were "affiliated more closely with non–Beta Israel Ethiopians and other East Africans".[56] A 2004 study by Shen et al. reached similar conclusions, that the Beta Israel were likely descended from local Ethiopian populations.[57]
A 2001 study by the Department of Biological Sciences at Stanford University found a possible genetic similarity between 11 Ethiopian Jews and four Yemenite Jews who took part in the testing. The differentiation statistic and genetic distances for the 11 Ethiopian Jews and four Yemenite Jews tested were quite low, among the smallest of comparisons involving either of these populations. The four Yemenite Jews from this study may be descendants of reverse migrants of African origin who crossed Ethiopia to Yemen. The study result suggests gene flow between Ethiopia and Yemen as a possible explanation for the closeness. The study also suggests that the gene flow between Ethiopian and Yemenite Jewish populations may not have been direct, but instead could have been between Jewish and non-Jewish populations of both regions.[58]
A 2002 study of mitochondrial DNA (which is passed through only maternal lineage to both men and women) by Thomas et al. showed that the most common mtDNA type found among the Ethiopian Jews sample was present only in Somalia. This further supported the view that all Ethiopian Beta Israel were of local or Ethiopian origin.[59]
A 2009 study of autosomal DNA (which is inherited from both parents) by Tishkoff et al. observed that the Beta Israel were predominantly of the Cushitic genetic cluster, typically found in populations from East Africa. The Beta Israel had elevated levels of the European genetic cluster compared to the other examined Ethiopian and East African populations in the Global Structure Run.[60]
A 2010 study by Behar et al. on the genome-wide structure of Jews observed that the Beta Israel had levels of the Middle Eastern genetic clusters similar to the Semitic-speaking Tigreans and Amharas. Compared to the Cushitic-speaking Oromos, who are the largest ethnic group in Ethiopia, the Beta Israel had higher levels of Middle Eastern admixture.[61]
A number of other DNA studies have been done on the Beta Israel.[62][63][64][65][66][67]
A 2012 study showed that although they more closely resemble the indigenous populations of Ethiopia, the Beta Israel have some distant Jewish ancestry, going back 2,000 years. This has resulted in speculation that the community was founded by a few Jewish itinerants who moved to Ethiopia, converted locals to Judaism, and married into the local population. This evidence has been used as an explanation as to why the Beta Israel had no idea about the holiday of Hanukkah until being airlifted to Israel—the holiday commemorates events in the 2nd century BC, long after their ancestors had already left Israel.

http://en.wikipedia.org/wiki/Beta_Israel#DNA_evidence

Anglojew
06-28-2013, 09:04 AM
They are partially defended from Judeans

http://failedmessiah.typepad.com/failed_messiahcom/2012/08/report-new-genetic-study-shows-that-ethiopian-jewish-community-is-ancient-pre-dating-the-destruction-234.html

Judeans took the Ark of the Covenant to Ethiopia which was when the community was founded. After the re-establishment of Israel the Ark could once again be taken to Israel so the Ethiopean Jews could return.

Methusalem
06-28-2013, 09:13 AM
They are partially defended from Judeans

http://failedmessiah.typepad.com/failed_messiahcom/2012/08/report-new-genetic-study-shows-that-ethiopian-jewish-community-is-ancient-pre-dating-the-destruction-234.html

Judeans took the Ark of the Covenant to Ethiopia which was when the community was founded. After the re-establishment of Israel the Ark could once again be taken to Israel so the Ethiopean Jews could return.

That's also mentioned in the wikiarticle:

A 2012 study showed that although they more closely resemble the indigenous populations of Ethiopia, the Beta Israel have some distant Jewish ancestry, going back 2,000 years. This has resulted in speculation that the community was founded by a few Jewish itinerants who moved to Ethiopia, converted locals to Judaism, and married into the local population. This evidence has been used as an explanation as to why the Beta Israel had no idea about the holiday of Hanukkah until being airlifted to Israel—the holiday commemorates events in the 2nd century BC, long after their ancestors had already left Israel.

The original study: http://failedmessiah.typepad.com/files/north-african-jewish-and-non-jewish-populations-form-distinctive-orthogonal-clusters.pdf

Deidara
06-28-2013, 06:47 PM
Interesting.

(s)AINT
06-28-2013, 07:17 PM
Ethiopians are the founders of European culture.

Deidara
06-28-2013, 07:19 PM
Ethiopians are the founders of European culture.

:biggrin:

Methusalem
06-28-2013, 07:19 PM
Ethiopians are the founders of European culture.

lol
troll