Version of 2007-06-16
Wersja polska • Wersja dwujęzyczna • Bilanguage version
By all appearances it seems that the history of the settling of Africa does not hide any secrets. The widely known and accepted model, called “Out of Africa”, assumes that the species Homo sapiens developed just in that continent, and that the current inhabitants of Africa are all descendants of those people who never left that land.
In respect of the language, the native population of Africa may be divided into 4 large groups, also termed phyla:
Several less known languages, such as Shabo (Ethiopia), Laal (Chad), Mpre (Ghana) or Bangi-me (Mali), may stay outside these 4 groups. The language classification does not fit strictly to the anthropological classification, at least because of the Pygmies who are distinct in many respects. They have not preserved their original language and now use languages of their Niger-Congo neighbours. Niger-Congo and Nilo-Saharan peoples seem to be distantly related, and that is why they all are termed Niger-Saharan. The shorter equivalent term Zinj is in use as well.
Linguistic (and partially also anthropological) researches allowed to formulate the assumption that the people of New Guinea (as well as of the Andamanes – all these people are termed Indo-Pacific) is closer in some respects to a part of the Africans, namely to the Zinj peoples, than other groups which inhabit continents colonized as the result of the out of Africa movement. This assumption is known as the Afro-Pacific hypothesis.
In the short paper “Implications of African Language Family Histories for Human History” Christopher Ehret has stated on the Afro-Pacific hypothesis:
“This hypothesis requires two initial streams of human movement out of Africa, one following the southern margins of Asia, eventually as far as New Guinea and nearby island chains. The second stream would have passed into western Asia and from there into Europe and across central and northern Asia and eventually into the Americas.”
According to this author, there were 4 main episodes in the history of the settling of Africa.
So, at first sight, things look fully explained. But from logical point of view, the explanation of known facts does not require those two postulated streams in the episodes 2 and 3 at all. Namely, it is also possible that the observed similarities are the result of a reverse migration of Indo-Pacific peoples in the past, 15–20 kya, i.e. a migration from New Guinea back to Africa.
Despite appearences, this statement sounds plausible. There is no reason to assume initially that a reverse movement is impossible some tens of thousands of years after colonizing a certain terrain even if we took a sea travel into consideration as the way of the movement. But probably as long as 60,000 years ago people were able to cross the sea somehow to reach Australia (this date seems to be more reliable now than 40,000, as given in older sources). So why not to suppose that 40–45 thousand years after the date of the first colonization of Australia other people were ready to cross the Indian Ocean and to reach the shores of Africa?
As it was stated above, there is some linguistic evidence for the postulated Afro-Pacific macrophylum (e.g. the presence of nominal classes in most languages that belong there). On the other hand, there exists no evidence for supposing that all the other out-of-African languages are related at the same level as Zinj (aka Niger-Saharan aka Niger-Congo + Nilo-Saharan) and Indo-Pacific.
And so, especially, contrary to some popular ideas, most real specialists doubt the Greenberg’s idea of “Amerindians” and criticize it strongly. Also the Australian Aborigenes completely do not fit to the two stream picture as they are not closer related to the Papuans and their languages are not considered a part of the Indo-Pacific macrophyllum.
But who give more serious evidence against the two initial stream assumption are geneticists. They state that the main out-of-Africa migration took place 80,000 BP, and no traces of two initial streams are recoverable. There is also a huge gap between the date of the leaving of Africa by the first humans and the date of the existence of the Proto-Zinj language community which is dated to 15–20 kya by Ehret. In addition, the date of colonization of New Guinea by Indo-Pacific peoples also seem to be much deeper in time.
All these all above mentioned facts imply the following conclusions on the settling of Africa:
1. There was only one initial stream of the out-of-Africa migration, some 80 thousand years ago, in full accordance to what geneticists say.
2. One of the first waves of that movement reached New Guinea (and probably also Tasmania and Andamanes): that was the wave of the Indo-Pacific language community. It may have taken place as long as 60,000 years ago, hence so much diversity of modern Indo-Pacific languages.
3. The Ainu people and so called Paleoindians may also be chips of the wave (and the first colonization of the Americas may have been much older than those 13,500 “Clovis” years – such a statement is in accordance to the linguistic picture of the New World but is unimportant for the problem discussed here).
4. Some 20,000–15,000 BP a back-to-Africa migration took place: a group of Indo-Pacific peoples came to Africa from New Guinea, possibly (but not necessarily) by sea.
5. The newcomers (the Zinj people) knew different technology and had different culture, and that is why they began to grow and to assimilate the pre-Niger-Saharan (NS) autochtons. We have an immediate proof for that process really happened: the Pygmies which are “physical” remnants of the pre-NS Africa. Both “physical” and language remnants of the African aborigines are the Khoisan. Those several African language isolates like Mpre, Bangi Me, maybe also Shabo, may be linguistic remnants of the pre-NS Africa at the same time.
In contrast, the two-stream view suggests that the proto-Afro-Pacific people lived in Africa together with the Khoisan and others for many thousands of years – then why we can observe the differences in their physical features now and in their genes? It would be expected that the physical and genetic differences in the continent would be less and less with time due to interbreeding (a common feature of our species) while the differences between African and non-African people would grow due to isolation. It is quite differently: the Zinj peoples are more similar to the New Guineans than to the Khoisan.
And when the split of the proto-AP into African and Indo-Pacific took place? Already 80,000 BP? If yes, why the Zinj remained similar to the Papuans for so long while the other peoples formed what we call races? What did the proto-Zinj do in Africa between 80 and 15 kya? Why did not they spread all over the continent then? But the climate was not dry during that whole period. Why did they stand calm until 15,000 BP and only then started to spread? What happened with them 15,000 years ago that namely then they attained superiority over the rest of the African population and became able to dominate over them? But they all must have been living side by side for some tens of thousands of years! So, why the Zinj people started to spread only 15,000 BP, and they were not able to have spread before?
Or maybe the Zinj – Indo-Pacific split took place only short time before the period of the Niger-Saharan language community, some 20,000 BP? But in this case the Papuans must have come to New Guinea only 15,000 BP which is doubtful from linguistic point of view. Who inhabited New Guinea before? Who colonized the Solomon Islands as early as 27,000 BP and remained traces, interpreted as primitive agriculture there. What was the history of the Tasmanians then (their extinct languages are counted as Indo-Pacific as well) who were probable ousted from Australia to Tasmania by the Australian Aborigines? Who lived in Australia already 40,000 and probably even 60,000 BP?
These questions and doubts concerning either scenarios made us believe in the back-to-Africa migration rather than in two initial streams of human movement out of Africa.
Here is the most interesting fragment from Roger Blench’s article “Genetics and linguistics in sub-Saharan Africa”:
“However, this did not satisfactorily explain why the best candidates for the descendants of the original Homo sapiens, the Khoesanoids of southern Africa, had a distinctly different phenotype. Strangely, there seems to be little trace of their physical type outside Africa. One possible explanation for this situation is that most present-day Africans resemble Papuans because their ancestors migrated from the eastern side of the Indian Ocean back westwards, re-entering Africa, with skills, technology and perhaps social/ritual systems, spread out across Africa, and gradually displaced or assimilated many of the resident populations. This argument seems to have been first put forward in its modern form by Kingdon (1993) although in the absence of modern genetic evidence it was little more than speculation. If this argument is accepted, these early immigrants would be at the origin of Nilo-Saharan, as this is the oldest of the resident phyla apart from Khoesan.”
[Blench believes that Niger-Congo is just one of the branches of Nilo-Saharan, see his other articles.]
Now let’s consider Afro-Asians who form the fourth language phyla of Africa. From the biological point of view, evolution of a population needs three things in order to happen: a pressure of the environment, an isolation, and sufficient time. A scenario in which human races (whatever it really means) originates just because of the fact that people inhabit various climatic zones seems to be a complete nonsense. Thus it must have been a period in the human history when relatively isolated and rather small populations existed in various climatic zones, practically without any contacts to other populations. This period must have lasted at least 20–40 thousand years. The time interval 80,000–40,000 BP is the best candidate: it was the period when people spread all over the world. It is also the period when the Afro-Pacific peoples must have lived in New Guinea and must have evolved there, in separation from other human beings.
As the methods of finding food at that period were primitive, people must have lived in great dispersal. Large distance migrations there and back were rare because of no known transport meanings and because of the adaptation only to the local environment. All those circumstances enabled originating of the human diversity which can be observed as what we call human races today. Of course, the language was strictly binded to the physical features of the body then – only quite not long ago languages began to spread through the boundaries of biological features.
Afro-Asians seem to be physically different from both Niger-Saharans and the Khoisan and closer to Indo-Europeans, even if the African parts of the family have been “Zinjized” for centuries (nota bene, their languages also have received some local features, esp. in Omotic, Cushitic and Chadic branches). The newest approaches exclude the Afro-Asiatic branch from the Nostratic macrofamily (which still includes Indo-European, Uralic, Altaic, Dravidian, possible also Eskimo-Aleut), nevertheless a relation between Afro-Asiatic and Nostratic at a little deeper degree is still maintained. Nostratic people were surely not those who were the first immigrants from Africa as they must have lived only 15,000 BP or so, and not 80,000 BP. So, the common language ancestor of both Afro-Asiatic and Nostratic must have existed some 25,000 BP. Those proto-Afro-Asiatic-Nostratic (“proto-Afro-Caucasians”) must have belonged to the “white race” and they must have lived outside Africa (possible somewhere in the Middle East).
In other words, both Afro-Asians and Niger-Saharans do not seem to be parts of the original population of the Africa, and those both huge groups are parts of the back-to-Africa movement. So, if it is correct, the ancestors of modern Amharas must have made two voyages there and back, four altogether:
1. from Africa to the Arabian Peninsula, 80,000 BP (the initial out-of-Africa stream),
2. from the Middle East back to the Corner of Africa, 20,000 BP (the Elamites may have been the closest relatives of the Afro-Asians which did not take part in this movement),
3. from Africa to the Middle East (maybe ca. 10,000 BP) – the migration of the proto-Semitic peoples,
4. from South Arabia to Ethiopia, so to Africa again.
There is nothing strange in such a scenario, taking under consideration the length of the period we are talking about. And if to believe the Bible, the Hebrew people (and their ancestors) made up even 5 journeys: 1–3 as above, 4 from the Middle East (Abraham was born in Ur in Mesopotamia) to Egypt and 5 from Egypt to Kanaan (Moses).
Thus we receive a simple and plausible picture of human migrations, simpler than that of Ehret, and more concordant with genetic data. Namely, 80,000 BP some people left Africa. From those who stayed there, only Khoisan (and maybe Pygmies) live today. Indeed, according to geneticists, the largest genetic gap is between the Bushmen and the rest of the humanity. This gap may be the result of the famous out-of-Africa migration 80,000 BP.