Autosomal DNA Scholars, such as Hodgson et al., present archaeogenetic evidence in favor for a place of dispersion within Africa, but argue that the speakers of Proto-Afroasiatic can ultimately be linked to a Paleolithic and pre-agricultural
migration wave into Africa from Western Asia, and that the Semitic branch represents a later back-migration to the Levant.According to an autosomal DNA research in 2014 on ancient and modern populations, the
Afroasiatic languages likely spread across Africa and the Near East by an ancestral population(s) carrying a newly identified "non-African" (Western Eurasian) genetic component, which the researchers dub the "Ethio-Somali" component. This genetic component is most closely related to the "
Maghrebi" component and is believed to have diverged from other "non-African" (Western Eurasian) ancestries at least 23,000 years ago. The "Ethio-Somali" genetic component is prevalent among modern Afroasiatic-speaking populations, and found at its highest levels among
Cushitic peoples in the
Horn of Africa. On this basis, the researchers suggest that the original Ethio-Somali carrying population(s) probably arrived in the pre-agricultural period (12–23 ka) from the
Near East, having crossed over into northeast Africa via the Sinai Peninsula and then split into two, with one branch continuing west across
North Africa and the other heading south into the Horn of Africa. They suggest that a descendant population migrated back to the
Levant prior to 4000 BC and developed the
Semitic branch of Afroasiatic. Later migration from Arabia into the Horn of Africa beginning around 3 ka would explain the origin of the
Ethio-Semitic languages at this time. A similar view has already been proposed earlier, suggesting that the ancestors of Afroasiatic speakers could have been a population originating in the Near East that migrated to
Northeast Africa during the
Late Palaeolithic with a subset later moving back to the Near East. Subsequent archaeogenetic studies have corroborated the migrations of Western Eurasian ancestry during the Paleolithic into Africa, becoming the dominant component of Northern Africa since at least 15,000 BC. The "Maghrebi" component, which gave rise to the
Iberomaurusian culture, is described as autochthonous to Northern Africa, related to the Paleolithic Eurasian migration wave, and the characteristic ancestry components of modern Northern Africans along a West-to-East cline, with Northeastern Africans having an additionally higher frequency of a Neolithic Western Asian component associated with the Neolithic expansion. Genetic research on Afroasiatic-speaking populations revealed strong correlation between the distribution of Afroasiatic languages and the frequency of Northern African/
Natufian/Arabian-like ancestry. In contrast,
Omotic speakers display ancestry mostly distinct from other Afroasiatic-speakers, indicating
language shift, or support for the exclusion of Omotic from the Afroasiatic group. Genetic studies on a specimen of the
Savanna Pastoral Neolithic excavated at the
Luxmanda site in Tanzania, which has been associated with migrations of
Cushitic-speaking peoples and the spread of pastoralism, found that the specimen carried a large proportion of ancestry related to the Pre-Pottery Neolithic culture of the Levant (
Natufian), similar to that borne by modern Afroasiatic-speaking populations inhabiting the Horn of Africa. It is suggested that a population related to the Pre-Pottery Neolithic culture of the Levant contributed significantly to historical Eastern African populations represented by the c. 5,000 year old Luxmanda specimen, while modern Cushitic-speaking populations have additional contributions from
Dinka-related and "Neolithic Iranian-related" sources. This type of ancestry was later partially replaced by following migration events associated with the
Bantu expansion, with
Bantu-speaking Eastern Africans having only little ancestry associated with the Pre-Pottery Neolithic culture of the Levant.
Y-chromosome evidence Keita (2008) examined a published Y-chromosome dataset on Afro-Asiatic populations and found that a key lineage
E-M35/
E-M78, sub-clade of haplogroup E, was shared between the populations in the locale of Egyptian and Libyan speakers and modern Cushitic speakers from the Horn. These lineages are present in Egyptians, Berbers, Cushitic speakers from the Horn of Africa, and Semitic speakers in the Near-East. He noted that variants are also found in the Aegean and Balkans, but the origin of the M35 subclade was in
Egypt or
Libya, and its clades were dominant in a core portion of Afro-Asiatic speaking populations which included
Cushitic,
Egyptian and
Berber groups, in contrast Semitic speakers showed a decline in frequency going west to east in the Levantine-Syria region. Keita identified high frequencies of M35 (>50%) among
Omotic populations, but stated that this derived from a small, published sample of 12. Keita also wrote that the PN2 mutation was shared by M35 and M2 lineages and this paternal clade originated from East Africa. He concluded that "the genetic data give population profiles that clearly indicate males of African origin, as opposed to being of Asian or European descent" but acknowledged that the biodiversity does not indicate any specific set of skin colors or facial features as populations were subject to microevolutionary pressures. Fregel summarized that the Y-chromosome diversity of North Africans was compatible with a demic expansion from the Middle East, because the age of common lineages in North Africa (E-M78 and J-304) were relatively recent. The North African pattern of Y-chromosome variation was mostly shaped during the
Neolithic period. Ehret cited genetic evidence which had identified the Horn of Africa as a source of a genetic marker "
M35/
215" Y-chromosome lineage for a significant population component which moved north from that region into Egypt and the Levant. Ehret argued that this genetic distribution paralleled the spread of the Afrasian language family with the movement of people from the Horn of Africa into Egypt and added a new demic component to the existing population of Egypt 17,000 years ago. == See also ==