African Pygmies are often assumed to be the direct descendants of the
Middle Stone Age hunter-gatherer peoples of the central
African rainforest. Genetic evidence for the deep separation of Congo Pygmies from the lineage of
West Africans and
East Africans, as well as
admixture from archaic humans, was found in the 2010s. The lineage of African Pygmies is strongly associated with mitochondrial (maternal line)
haplogroup L1, with a divergence time between 170,000 and 100,000 years ago. They were partially absorbed or displaced by later immigration of agricultural peoples of the
Central Sudanic and
Ubangian phyla beginning after about
5,500 years ago, and, beginning about
3,500 years ago, by the
Bantu, adopting their languages.
Linguistic substrate Substantial non-
Bantu and non-
Ubangian substrates have been identified in Aka and in Baka, respectively, on the order of 30% of the lexicon. Much of this vocabulary is botanical, deals with
honey harvesting, or is otherwise specialized for the forest and is shared between the two western Pygmy groups. This substrate has been suggested as representing a remnant of an ancient "western Pygmy" linguistic phylum, dubbed "Mbenga" or "Baaka". However, as substrate vocabulary has been widely borrowed between Pygmies and neighboring peoples, no reconstruction of such a "Baaka" language is possible for times more remote than a few centuries ago. An ancestral Pygmy language has been postulated for at least some Pygmy groups, based on the observation of
linguistic substrates. According to
Merritt Ruhlen (1994), "African Pygmies speak languages belonging to either the
Nilo-Saharan or the
Niger–Kordofanian family. It is assumed that Pygmies once spoke their own language(s), but that, through living in symbiosis with other Africans, in prehistorical times, they adopted languages belonging to these two families."
Roger Blench (1997, 1999) criticized the hypothesis of an ancestral "Pygmy language", arguing that even if there is evidence for a common ancestral language rather than just borrowing, it will not be sufficient to establish a specifically "Pygmy" origin rather than any of the several potential
language isolates of (former) hunter-gatherer populations that ring the rainforest. He argued that the Pygmies do not form the residue of a single ancient stock of Central African hunter-gatherers, but that they are rather descended from several neighboring ethno-linguistic groups, independently adapting to forest subsistence strategies. Blench adduced the lack of clear linguistic and archaeological evidence for the antiquity of the African Pygmies, that the genetic evidence, at the time of his writing, was inconclusive, and that there is no evidence of the Pygmies having a hunting technology distinctive from that of their neighbors. He argued that the short stature of Pygmy populations can arise relatively quickly (in less than a few millennia) under strong selection pressures.
West African hunter-gatherers may have spoken a set of presently
extinct Sub-Saharan
West African languages. In the northeastern region of
Nigeria,
Jalaa, a language isolate, may have been a descending language from the original set(s) of languages spoken by West African hunter-gatherers.
Genetics Genetic studies have found evidence that African Pygmies are descended from the
Middle Stone Age people of Central Africa, with a separation time from West and East Africans of the order
130,000 years. African Pygmies in the historical period have been significantly displaced by, and assimilated to, several waves of
Niger–Congo and
Nilo-Saharan speakers, of the
Central Sudanic,
Ubangian, and
Bantu phyla. African pygmies'
uniparental markers display the most ancient divergence from other human groups among anatomically modern humans, second only to those displayed among some
Khoisan populations. Researchers identified an ancestral and autochthonous lineage of mtDNA shared by Pygmies and Bantus, suggesting that both populations were originally one, and that they started to diverge from common ancestors around 70,000 years ago. After a period of isolation, during which current phenotype differences between Pygmies and Bantu farmers accumulated, Pygmy women started marrying male Bantu farmers (but not the opposite). This trend started around 40,000 years ago, and continued until several thousand years ago. Subsequently, the Pygmy gene pool was not enriched by external gene influxes. Mitochondrial
haplogroup L1c is strongly associated with pygmies, especially with
Bambenga groups. L1c prevalence was variously reported as: 100% in
Ba-Kola, 97% in
Aka (Ba-Benzélé), and 77% in
Biaka, 100% of the
Bedzan (Tikar), 97% and 100% in the
Baka people of
Gabon and
Cameroon, respectively, 97% in
Bakoya (97%), and 82% in
Ba-Bongo. Patin, et al. (2009) suggest two unique, late
Pleistocene (before 60,000 years ago) divergences from other human populations, and a split between eastern and western pygmy groups about 20,000 years ago.
Ancient DNA Ancient DNA was able to be obtained from two
Shum Laka foragers from the early period of the Stone to Metal Age, in 8000 BP, and two Shum Laka foragers from the late period of the Stone to Metal Age, in 3000 BP. The mitochondrial DNA and Y-Chromosome haplogroups found in the ancient Shum Laka foragers were Sub-Saharan African haplogroups. Two earlier Shum Laka foragers were of
haplogroup L0a2a1 – broadly distributed throughout modern African populations – and two later Shum Laka foragers were of
haplogroup L1c2a1b – distributed among both modern West and Central African agriculturalists and hunter-gatherers. One earlier Shum Laka forager was of haplogroup B and one later Shum Laka forager haplogroup B2b, which, together, as
macrohaplogroup B, is distributed among modern Central African hunter-gatherers (e.g.,
Baka,
Bakola,
Biaka,
Bedzan). The autosomal admixture of the four ancient Shum Laka forager children was ~35% Western
Central African hunter-gatherer and ~65%
Basal West African – or, an admixture composed of a modern western Central African hunter-gatherer unit, a modern
West African unit, existing locally before 8000 BP, and a modern
East African/West African unit likely from further north in the regions of the
Sahel and
Sahara. The two earlier Shum Laka foragers from 8000 BP and two later Shum Laka foragers from 3000 BP show 5000 years of population continuity in region. Yet, modern peoples of Cameroon are more closely related to modern West Africans than to the ancient Shum Laka foragers. Modern Cameroonian hunter-gatherers, while partly descended, are not largely descended from the Shum Laka foragers, due to the apparent absence of descent from Basal West Africans. The
Bantu expansion is hypothesized to have originated in a homeland of Bantu-speaking peoples located around western Cameroon, a part of which Shum Laka is viewed as being of importance in the early period of this expansion. By 3000 BP, the Bantu expansion is hypothesized to have already begun. Yet, the sampled ancient Shum Laka foragers – two from 8000 BP and two from 3000 BP – show that most modern
Niger–Congo speakers are greatly distinct from the ancient Shum Laka foragers, thus, showing that the ancient Shum Laka people were not the ancestral source population of the modern
Bantu-speaking peoples. While
Southern African hunter-gatherers are generally recognized as being the earliest divergent modern human group, having diverged from other groups around 250,000–200,000 BP, as a result of the sampling of the ancient Shum Laka foragers,
Central African hunter-gatherers are shown to have likely diverged at a similar time, if not even earlier. == Short stature ==