Afroasiatic Urheimat

The Afroasiatic "Urheimat" is the hypothetical place where speakers of the proto-Afroasiatic language lived in a single linguistic community, or complex of communities, before this original language dispersed geographically and divided into separate distinct languages. This speech area is known as the "Urheimat" ("original homeland" in German). Afroasiatic languages are today distributed in parts of Africa and Western Asia.
The contemporary Afroasiatic languages are spoken in the Near East, North Africa, the Horn of Africa, and parts of the Sahara/Sahel. The various hypotheses for the Afroasiatic "Urheimat" are distributed throughout this territory; that is, it is generally assumed that proto-Afroasiatic was spoken in some region where Afroasiatic languages are still spoken today. However, there is argument as to which part of the contemporary Afroasiatic speech area corresponds with the original homeland.
Date of Afroasiatic.
The earliest written evidence of an Afroasiatic language is an Ancient Egyptian inscription dated c. 3400 BC (5,400 years ago). Symbols on Gerzean pottery resembling Egyptian hieroglyphs date back to c. 4000 BC, suggesting a still earlier possible date. This gives us a minimum date for the age of Afroasiatic. However, Ancient Egyptian is highly divergent from proto-Afroasiatic (Trombetti 1905: 1–2), and considerable time must have elapsed in between them. Estimates of the date at which the proto-Afroasiatic language was spoken vary widely. They fall within a range between approximately 7,500 BC (9,500 years ago) and approximately 16,000 BC (18,000 years ago). According to Igor M. Diakonoff (1988: 33n), proto-Afroasiatic was spoken c. 10,000 BC. According to Christopher Ehret (2002: 35–36), proto-Afroasiatic was spoken c. 11,000 BC at the latest, and possibly as early as c. 16,000 BC. These dates are older than dates associated with most other protolanguages. Culturally this falls within the period of the Halfan culture which may have been proto-Afroasiatic.
Urheimat hypotheses.
Levant theory.
Supporters of a non-North or north East African origin for Afroasiatic are particularly common among those with a background in Semitic or Egyptological studies, or amongst archaeological proponents of the "farming/language dispersal hypothesis" according to which major language groups dispersed with early farming technology in the Neolithic. The leading linguistic proponent of this idea in recent times is Alexander Militarev. Arguments for and against this position depend upon the contested proposal that farming-related words can be reconstructed in Proto-Afroasiatic, with farming technology being widely thought to have spread from the Levant into North Africa and then the Horn of Africa.
Militarev, who linked proto-Afroasiatic to the Levantine Natufian culture, that preceded the spread of farming technology, believes the language family to be about 10,000 years old. He wrote (Militarev 2002, p. 135) that the "Proto-Afrasian language, on the verge of a split into daughter languages", meaning, in his scenario, into "Cushitic, Omotic, Egyptian, Semitic and Chadic-Berber", "should be roughly dated to the ninth millennium BC". But an Asiatic origin need not be associated exclusively with the migration of agricultural populations: according to linguists, words for dog (an Asian domesticate) reconstruct to Proto-Afroasiatic as well as words for bow and arrow, which according to some archaeologists spread rapidly across North Africa once they were introduced to North Africa from the Near East i.e. Ounan points.
Red Sea/Horn of Africa theory.
The Horn of Africa, particularly the area of Ethiopia and Eritrea, has been proposed by some linguists as the origin of the language group because it includes the majority of the diversity of the Afroasiatic language family and has very diverse groups in close geographic proximity, sometimes considered a telltale sign for a linguistic geographic origin. Within this hypothesis there are competing variants.
Red Sea coast.
Christopher Ehret has proposed the western Red Sea coast from Eritrea to southeastern Egypt. While Ehret disputes Militarev's proposal that Proto-Afroasiatic shows signs of a common farming lexicon, he suggests that early Afroasiatic languages were involved in the even earlier development of intensive food collection in the areas of Ethiopia and Sudan. In other words, he proposes an even older age for Afroasiatic than Militarev, at least 15,000 years old and possibly older, and believes farming lexicon can only be reconstructed for branches of Afroasiatic. But, it is argued, the appearance of linguistic terms such as dog, bow, and arrow in Proto-Afroasiatic makes a date earlier than 9,500 BC (coinciding with the end of the Younger Dryas) highly unlikely since dogs only appear at the earliest in the archaeological record after 12,000 BC in the Near East, and arrowheads only appear after 9,500 BC in North Africa and the Horn of Africa as a result of introduction from the Near East. However, microlithic arrowheads appear in southern Africa (71,000 BP) and possibly the Aterian culture (ca. 100,000-25,000 BP) suggesting that arrowheads "may" have been an invention originating in Africa and taken into the Near East by a pre-Afroasiatic late glacial migration. At the site of Nataruk in Turkana County, Kenya, obsidian bladelets found embedded in a skull and within the thoracic cavity of another skeleton dated to ca. 10,000 BP, may suggest the use of stone-tipped arrows as weapons. After the end of the last glacial period, use of the bow seems to have spread to every inhabited continent, including the New World, except for Australia. However, these finds predate by far any proposed date for the evolution of Afroasiatic.
In the next phase, unlike many other authors Ehret proposed an initial split between northern, southern and Omotic. The northern group includes Semitic, Egyptian and Berber (agreeing with others such as Diakonoff). He proposed that Chadic stems from Berber (some other authors group it with southern Afroasiatic languages such as Cushitic ones).
Ethiopia.
Roger Blench has proposed Southwestern Ethiopia, in or around the Omo Valley. Compared to Militarev and Ehret he proposed a relatively young time-depth of approximately 7,500 years. Like Ehret he accepts that Omotic is Afroasiatic and sees the split of northern languages from Omotic as an important early development, but he did not group Egyptian or Chadic with any of these.
North Africa theory.
Another proposal is that Semitic is an offshoot of a northern family of Afroasiatic languages, including Berber, and possibly Egyptian. It then entered the Levant and was possibly spread by what Juris Zarins calls the Syro-Arabian nomadic pastoralism complex, spreading south along the shores of the Red Sea and northeast around the edge of the "Fertile Crescent". 
It is thought that Semitic speakers then crossed from South Arabia back into Eritrea.
In contrast, Bender proposed on linguistic grounds that Cushitic (found in the Horn of Africa) shares important innovations with Semitic and Berber, and that these three split off early from the others, while still near an original homeland of all Afroasiatic.
Sahel/Sahara theory.
Igor Diakonoff proposed the Eastern Sahara region, specifically the southern fringe of the Sahara.
Lionel Bender proposed the area near Khartoum, Sudan, at the confluence of the Blue Nile and White Nile. The details of his theory are widely cited but controversial, as it involves the proposal that Semitic originated in Ethiopia and crossed to Asia directly from there over the Red Sea. This could also potentially solidify Bender's argument, in that scholars today believe that there is a relationship between the Cushitic branch and the Chadic Branch; arguing that perhaps Chadic descends from Cushitic.
Evidence from population genetics.
The most commonly cited genetic marker in recent decades has been the Y chromosome, which is passed from father to son along paternal lines in un-mixed form, and therefore gives a relatively clear definition of one human line of descent from common ancestors. There is a high frequency of haplogroup E1b1b in select Afro-Asiatic speakers.
Several branches of humanity's Y-DNA family tree have been proposed as having an association with the spread of Afroasiatic languages.
1. Haplogroup E1b1b is thought to have originated in the Horn of Africa and to have migrated out of Africa between 47,000 and 28,500 years ago. In general, Afroasiatic speaking populations have relatively high frequencies of this haplogroup, with the notable exception of Chadic speaking populations. Christopher Ehret and Shomarka Keita have suggested that the geography of the E1b1b lineage coincides with the distribution of Afroasiatic languages.
2. Haplogroup J1c3 (Y-DNA), previously known as "J1e", is actually a more common paternal lineage than E1b1b in most Semitic speaking populations, but this is associated with Middle Eastern origins and has apparently been spread from there after the original dispersion of Afroasiatic.
3. Haplogroup R1b1a (R-V88), and specifically its sub-clade R-V69, has a very strong relationship with Chadic speaking populations, who unlike other Afroasiatic speakers have low frequencies of Haplogroup E1b1b. The majority of R-V88 was found in northern and central Africa, in Chadic-speaking populations. It is less common in neighbouring populations. The authors also found evidence of high concentration in Western Egypt and evidence that the closest related types of R1b are found in the Middle East in the Levant, and to a lesser extent southern Europe. They proposed that an Eastern Saharan origin for Chadic R1b would agree with linguistic theories such as those of Christopher Ehret, that Chadic and Berber form a related group within Afroasiatic, which originated in the area of the Sahara. R1b-V88 had probably entered Africa from Western Asia, via Egypt, and moved south along the Nile river and eventually crossing over to West Africa between 9,200 and 5,600 years ago.
In contrast to the evidence from paternally inherited Y-DNA, a recent study has shown that a branch of mitochondrial haplogroup L3 links the maternal ancestry of Chadic-speakers from the Sahel with Cushitic-speakers from the Horn of Africa.
Other mitochondrial lineages that are associated with Afroasiatic include mitochondrial haplogroups M1 and haplogroup U6. Gonzalez et al. 2007 suggest that Afroasiatic speakers may have dispersed from the Horn of Africa carrying the subclades M1a and U6a1.
According to an autosomal DNA study by Hodgson et al. (2014), the Afroasiatic languages were likely spread across Africa and the Near East by an ancestral population(s) carrying a newly identified non-African genetic component, which the researchers dub the "Ethio-Somali". This Ethio-Somali component is today most common among Afroasiatic-speaking populations in the Horn of Africa. It is most closely related to the Maghrebi non-African genetic component, and is believed to have diverged from all other non-African ancestries at least 23,000 years ago. On this basis, the researchers suggest that the original Ethio-Somali carrying population(s) probably arrived in the pre-agricultural period from the Near East, having crossed over into northeastern Africa via the Sinai peninsula. The population then likely split into two branches, with one group heading westward toward the Maghreb and the other moving south into the Horn. A related hypothesis that associates the origin of the ancestors of Afroasiatic speakers as the result of a reflux population from Southwest Asia during the Late Palaeolithic was previously put forward by Daniel McCall.
Nostratic hypothesis.
The Nostratic language family is a proposed macrofamily grouping together a number of language families including Indo-European, Uralic, Altaic, and even more controversially Afroasiatic. Following Pedersen, Illich-Svitych, and Dolgopolsky, most advocates of the theory have included Afroasiatic in Nostratic, though criticisms by Joseph Greenberg and others from the late 1980s onward suggested a reassessment of this position.
Ilya Yabonovich and other linguists, in examining the differences between the various members of the Afroasiatic family have realised that all of the old etymologies for this group were inherently semitocentric. The differences between Chadic, Omotic, Cushitic and Semitic, were wider than those seen between any members of the Indo-European family and as wide as some of the differences seen within and between separate language families, for example, Indo-European and Altaic. Certainly the exclusion of Afroasiatic from the controversial Nostratic family has simplified matters of phonemics, not having to include the complex patterns seen in Afroasiatic languages.
Allan Bomhard (1994) retains Afroasiatic within Nostratic, despite his admission that Proto–Afroasiatic is very different from the other members of the proposed linguistic Nostratic superfamily. As a result, he suggests it was probably the first language to have split from the Nostratic linguistic superfamily.
Recently, however, a consensus has been emerging among proponents of the Nostratic hypothesis. Greenberg in fact basically agreed with the Nostratic concept, though he stressed a deep internal division between its northern 'tier' (his Eurasiatic) and a southern 'tier' (principally Afroasiatic and Dravidian). The American Nostraticist Bomhard considers Eurasiatic a branch of Nostratic alongside other branches: Afroasiatic, Elamo-Dravidian, and Kartvelian. Similarly, Georgiy Starostin (2002) arrives at a tripartite overall grouping: he considers Afroasiatic, Nostratic and Elamite to be roughly equidistant and more closely related to each other than to anything else. Sergei Starostin's school has now re-included Afroasiatic in a broadly defined Nostratic, while reserving the term Eurasiatic to designate the narrower subgrouping which comprises the rest of the macrofamily. Recent proposals thus differ mainly on the precise placement of Dravidian and Kartvelian.