Some linguists’ proposals for grouping within Afroasiatic
What follows is a collection of factual observations about the population genetics of Afro-Asiatic language family speakers and populations in some ways related to or distinct from them, and some analysis of those facts. It is a work in progress towards making sense of the hard to fit together puzzle pieces of a complex linguistic family’s origins:
Afroasiatic (Afro-Asiatic), also known as Afrasian and traditionally Hamito-Semitic (Chamito-Semitic), is a large language family, of several hundred related languages and dialects. There are about 300 or so living languages and dialects, according to the 2009 Ethnologue estimate.
It includes languages spoken predominantly in the Middle East, North Africa, the Horn of Africa, and parts of the Sahel. It is generally assumed that Proto-Afroasiatic was spoken in some region where Afroasiatic languages are still spoken today. However, there is no consensus as to which part of the contemporary Afroasiatic areal corresponds to the original homeland.
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 7500 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 proto-languages. Culturally this falls within the period of the Halfan culture which may have been Proto-Afroasiatic.
The Halfan industry is one of the earliest known backed-bladelet industry in Eastern Africa and is dated to 18,000 and 12,500 BC in Nubia and Egypt. Christopher Ehret proposes that the Proto-Afro-Asiatic languages may have begun to spread from this area at about this time period, leading to the speculation that Halfan people may have spoken a variant of the Afro-Asiatic languages.
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.
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 Horn of Africa. 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), formally 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. This was announced in 2010 by Cruciani et al. 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, 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.
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 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 Horn of Africa carrying the subclades M1a and U6a1.