Monday, January 7, 2013

Genetic Data Disfavor Levant Origin For Afro-Asiatic

A new study on East African population genetics argues that it supports the finding that the Afro-Asiatic languages (e.g. ancient Egyptian, Hebrew, Arabic, many Ethiopian languages (from multiple Afro-Asiatic language families), Hasua, Berber), have a Northeast African rather than an Levantine origin.

The Essence of the Afro-Asiatic Urheimat Debate

The analysis that goes into resolving this ancient question of historical lingustics is quite involved.

The biggest argument for a Levatine origin for these languages is that language families have tended to expand with the migrations of the first farmers.  Farming undeniably arose in Jericho in the Levant, a thousand years or so before it spread to Africa, most notably in the civilization of ancient Egypt.  The Egyptian Neolithic revolution involved domesticated species of plants and animals that mostly derived from the Fertile Crescent Neolithic (the donkey is an Egyptian domestic exception that proves the rule).  Historically, although far less so these days, the Levantine hypothesis carried with it notion of Eurasian racial superiority relative to Africans.

The biggest arguments for an African origin of the Afro-Asiatic languages are that all but one of the six major sub-families of the Afro-Asiatic language family were exclusively African in geographic extent at historically known points in time (the six families are Semitic, Coptic, Berber, Chadic, Cushitic and Omotic).  The expansion of Hebrew and Arabic beyond Southwest Asia are historically documented phenomena. 

African has greater historic linguistic diversity within the language family than Southwest Asia.  Also, the Levatine branch (Semitic) does not appear to harbor any genetic component shared by all Afro-Asiatic language family speakers, while Semitic language speaking populations do have some African genetic component.  This last point is underscored by the latest study.  Many supporters of African origins for Afro-Asiatic languages are motivated more by an ideological commitment to Afrocentric perspectives than by the strong but not unequivocal linguistic, genetic and archaeological evidence that supports this perspective.

It doesn't help that there is no linguistic consensus on the relationship of the six major Afro-Asiatic linguistic families to each other.  Genetic arguments are complicated by differing patterns of paternal and matrilineal descent in the relevant populations. 

The only real point of consensus in this pitched debate on matters that aren't historicallly documented is that the Ethio-Semitic languages have a common Levantine origin in a single Semitic proto-language sometime near the boundary between when ancient history and prehistory meet, and that the local ancestors of the Ethiosemites spoke some manner of Cushitic language. 

But, the Ethio-Semitic layer genetically may have been thinner that early estimates looking merely at Eurasian and African contributions to Ethio-Semitic population genetics would have suggested, because many Cushitic populations also have substantial Eurasian genetic components.

More Complex Scenarios

The trouble with all of the simple arguments is that they may oversimplify a complex process. 

For example, it could be the case that Egypt received agriculture from the Levant substantially via technology transfer that included a mass language shift, rather than by demographic replacement, and that other Afro-Asiatic languages derive from an ethnically Egyptian Neolithic expansion.  In this scenario, for example, Semitic languages might be Egyptian derived even though Egyptian itself could have a Levantine origin; in this scenario Chadic and Cushitic respectively might be Blue Nile and White Nile offshoots of ancient Egyptian (a.k.a. the Coptic language) speaking pioneers.  A Levatine pro-Afro-Asiatic language might be lost entirely, replaced by a backmigrating wave of Afro-Asiatic language speakers who transmitted the Semitic languages.

Populations that are linguistically Berber are a quite pausible case, given their genetic makeup, for genetic continuity despite language shift to an Afro-Asiatic family language. 

Linguistically Chadic populations, in contrast, are quite genetically distinctive, for example, having high frequencies of Y-DNA haplogroup R1b-V88, relative to neighboring non-Afro-Asiatic populations and relative to other Afro-Asiatic populations.  Their relative lack of admixture with neighboring populations until the 20th century suggests a fairly recent origin for this language family relative to other Afro-Asiatic language families.

Linguistically Omotic populations (the smallest of the major Afro-Asiatic language families) could conceivably have arisen from areal influences and creolization between Cushitic speakers who border them on the East, and Nilotic language speakers who border them on the West.  


andrew said...

Ethio Helix comments here. He finds little new in the paper, but a discussion between Maju and he in the comments, in which he suggests a Mesolithic expansion of Afro-Asiatic into Palestine bears noting:

Maju January 8, 2013 12:03 AM

I think that this can be reasonably explained as pre-Neolithic Egyptian influences into Palestine, where the PPNA and very especially the Harifian (desert pastoralists) may have adopted it. These pre-Neolithic influences also explain E1b in the Levant and as far as Greece, where it arrived via West Asia almost for sure, causing a founder effect which may well be Mesolithic rather than Neolithic.

After the expansion of PPNB from Kurdistan/Turkey (languages related to Caucasus surely), the so-called Circum-Arabian Pastoralist Complex (CAPC) probably inherited the language and traditions from Harifian (even if generically absorbed into PPNB, it retains Harifian roots as far as I know).

Then in the 4th millennium BCE, at the edge of History, they expanded quite suddenly into the agricultural regions around their semi-desertic econiche (the mythical "flood", which is probably a wordplay in Sumerian between amaru=flood and a-maru=semites, also known as amurru). I can only imagine that climatic conditions were at play but whatever the case this is pretty much documented archaeologically and, in the case of Sumer, also in text (only "after the flood" Semitic names begin to appear).

. . . it'd be nice if we'd also have good archaeological information from Arabia, very especially the Hedjaz, which may well have played a role in the formation of the CAPC or in the backflow of early Semitic branches into Africa (Ethiopia). . . . [discussed the usefulness of better Y-DNA J1 data]

Replies Ethio HelixJanuary 8, 2013 12:27 PM

. . . the internal classification of Afroasiatic has not reached consensus, for instance the '[C]oreAfrasan' group which includes Chadic, berber, ancient egyptian and semtic, and that is championed by Ehret is contrasted with Lionel Bender's 'Macro-Cushitic' which groups berber, cushitic and semitic together, incidentally, if you take some of the E-M35 lineage frequency distributions at face value, and make the following rough oeverlaps: E-M81 - Berber, E-M78 -Ancient Egyptian, E-M123 -Semitic, E-V42/M293 -Cushitic/Southern cushitic then the SNP E-Z827 that unites M123, M81, V42 and M293 but excludes M78 would better mirror Bender's classification than Ehret's . . . [but notes that new developments couuld override these observations].

Asar Imhotep said...

It's interesting that you speak on the "Afrocentric" perspective on this matter, as if the African centered linguistic analysis was somehow based on intuition rather than sound linguistics. Not only do we reject a Leventine hypothesis for Afro-Asiatic, we reject the very notion of Afro-Asiatic as a language phylum. This is the residue of Greensberg's mass comparison. This was not a theory based on quantitative studies. Africanists are good for "come up with language family first, find evidence for it later." No Afro-Asiatic phylum has been proved using the comparative method. The piss poor jobs of Ehret and Stolbova demonstrate this fact. It is a sham and now we have folks trying make genealogical comparisons on a language hypothesis that hasn't even been proved. This is the sloppy scholarship of Africanists and the Eurocentric camp. Prove phylum using the comparative method, then attempt to ask other questions. Africanists are the creationists of linguistics.