The African Pygmies (or Congo Pygmies, variously also “Central African foragers”, “African rainforest hunter-gatherers” (RHG) or “Forest People of Central Africa”) are a group of tribal ethnicities, traditionally subsisting in a forager and hunter-gatherer lifestyle, native to Central Africa, mostly the Congo Basin.
The African Pygmies are divided into three roughly geographic groups:
- the western Bambenga or Mbenga (Cameroon, Gabon, Republic of the Congo, Central African Republic),
- the eastern Bambuti or Mbuti of the Congo basin (DRC)
- the central and southern Batwa or Twa (Rwanda, Burundi, DRC, Tanzania, Uganda, Zambia, Angola and Namibia). The more widely scattered (and more variable in physiology and lifestyle) Southern Twa are also grouped under the term Pygmoid.
They are notable for, and named for, their short stature (described as “pygmyism” in anthropological literature). They are assumed to be descended from the original Middle Stone Age expansion of anatomically modern humans to Central Africa, albeit substantially affected by later migrations from West Africa, from their first appearance in the historical record in the 19th century limited to a comparative small area within Central Africa, greatly decimated by the prehistoric Bantu expansion, and to the present time widely affected by enslavement and cannibalism at the hand of neighboring Bantu groups.
Most contemporary Pygmy groups are only partially foragers and partially trade with neighboring farmers to acquire cultivated foods and other material items; no group lives deep in the forest without access to agricultural products. A total number of about 900,000 Pygmies were estimated at living in the Central African Forests in 2016, about 60% of this number in the Democratic Republic of Congo. The number does not including Southern Twa populations, who live outside of Central Africa forest environment, partly in open swamp or desert environments.
The term Pygmy, as used to refer to diminutive people, derives from Greek πυγμαίος pugmaios (via Latin Pygmaeus, plural Pygmaei), a term for “dwarf” from Greek mythology. The word is derived from πυγμή, a term for “cubit”, suggesting a diminutive height.
The use of “Pygmy” in reference to the small-framed African hunter-gatherers dates to the early 19th century, in English first by John Barrow, Travels Into the Interior of Southern Africa (1806). However, the term was used diffusely, and treated as unsubstantiated claims of “dwarf tribes” among the Bushmen of the interior of Africa, until the exploration of the Congo basin of the 1870s. A commentator writing in 1892 claimed that, thirty years ago (viz., in the 1860s), “nobody believed in the existence of African dwarf tribes” and that “it needed an authority like Dr. Schweinfurth to prove that pygmies actually exist in Africa” (referencing Georg August Schweinfurth’s The Heart of Africa, published 1873). “African Pygmy” is used for disambiguation from “Asiatic Pygmy”, a name applied to the Negrito populations of Southeast Asia.
Dembner (1996) reported a universal “disdain for the term ‘pygmy'” among the Pygmy peoples of Central Africa: the term is considered a pejorative, and people prefer to be referred to by the name of their respective ethnic or tribal groups, such as Bayaka, Mbuti and Twa. There is no clear replacement for the term “Pygmy” in reference to the umbrella group. A descriptive term that has seen some use since the 2000s is “Central African foragers”.
Regional names used collectively of the western group of Pygmies are Bambenga (the plural form of Mbenga), used in the Kongo language and Bayaka (the plural form of Aka/Yaka), used in the Central African Republic.
The Congo Pygmy speak languages of the Niger–Congo and Central Sudanic language families. There has been significant intermixing between the Bantu and Pygmies.
There are at least a dozen Pygmy groups, sometimes unrelated to each other. They are grouped in three geographical categories:
- the western Bambenga (Mbenga) of Cameroon and Gabon, the Bayaka (Aka and Baka), the Bakola or Bakoya (Gyele and Kola), and the Bongo. These groups are speakers of Bantu and Ubangian languages
- The Bambuti (Mbuti) of the Ituri Rainforest, speakers of Bantu and Central Sudanic languages
- the widely scattered Batwa:
- the Great Lakes Twa of the Great Lakes, speakers of the Bantu Rundi and Kiga languages.
- the “Pygmoid” Southern Twa, not always included in the term “Pygmy”, as they tend to be somewhat taller (male average above 155 cm). Subgroups include the Echuya Twa, Mongo Twa, Lukanga Twa and Kafwe Twa.
African Pygmies are often assumed to be the direct descendants of the Middle Stone Age hunter-gatherer peoples of the central African rain forest. 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 2010’s. 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.
Genetic studies have found evidence for the African Pygmies being descended from the Middle Stone Age peopling 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-Congospeakers, of the Central Sudanic, Ubangian, and Bantu phyla.
Genetically, African pygmies has some key difference between them and Bantu peoples. 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. Mitochondrial haplogroups L2a and L0a are prevalent among the Bambuti
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.
Various hypotheses have been proposed to explain the short stature of African pygmies. Blecker, et al., suggest African pygmyism may have evolved as an adaptation to the significantly lower average levels of ultraviolet light available beneath the canopy of rainforest environments. In similar hypothetical scenarios, because of reduced access to sunlight, a comparatively smaller amount of anatomically formulated vitamin D is produced, resulting in restricted dietary calcium uptake, and subsequently restricted bone growth and maintenance, resulting in an overall population average skeletal mass near the lowest periphery of the spectrum among anatomically modern humans.
Other proposed explanations include the potentially lesser availability of protein-rich food sources in rainforest environments, the often reduced soil-calcium levels in rainforest environments, the caloric expenditure required to traverse rainforest terrain, insular dwarfism as an adaptation to equatorial and tropical heat and humidity, and pygmyism as an adaptation associated with rapid reproductive maturation under conditions of early mortality.
Additional evidence suggests that, when compared to other Sub-Saharan African populations, African pygmy populations display unusually low levels of expression of the genes encoding for human growth hormone and its receptor associated with low serum levels of insulin-like growth factor-1 and short stature.
A study by Prince, et al., provides insight into the role genetics plays in the reduced stature of African pygmies:
The short stature of Pygmy groups around the world has long intrigued anthropologists. It is generally accepted that their small body size is a result of genetic adaptation; however, which genes were selected, and the nature of the underlying selective force(s), remain unknown. The various hypotheses proposed include adaptations to food limitation, thermoregulation, mobility in the forest, and/or short lifespan. A recent study of the HGDP-CEPH populations identified a signal of selection in the insulin growth factor signalling pathway in Biaka Pygmies, which might be associated with short stature, but this signal was not shared with Mbuti Pygmies. By contrast, we found strong signals for selection in both African Pygmy groups at two genes involved in the iodide-dependent thyroid hormone pathway: TRIP4 in Mbuti Pygmies; and IYD in Biaka Pygmies . Intriguingly, a previous study found a significantly lower frequency of goiter in Efe Pygmies (9.4%) than in Lese Bantu farmers (42.9%). The Efe and Lese live in close proximity to one another in the iodine-deficient Ituri Forest and share similar diets. Moreover, the frequency of goiter in Efe women living in Bantu villages was similar to that of Efe women living in the forest, and the frequency of goiter in offspring with an Efe mother and a Lese father was intermediate between that of Efe and Lese. These observations suggest that the Efe have adapted genetically to an iodine-deficient diet; we suggest that the signals of recent positive selection that we observe at TRIP4 in Mbuti Pygmies and IYD in Biaka Pygmies may reflect such genetic adaptations to an iodine-deficient diet. Furthermore, alterations in the thyroid hormone pathway can cause short stature. We therefore suggest that short stature in these Pygmy groups may have arisen as a consequence of genetic alterations in the thyroid hormone pathway. If this scenario is true, then there are two important implications. First, this would suggest that short stature was not selected for directly in the ancestors of Pygmy groups, but rather arose as an indirect consequence of selection in response to an iodine-deficient diet. Second, since different genes in the thyroid hormone pathway show signals of selection in Mbuti vs. Biaka Pygmies, this would suggest that short stature arose independently in the ancestors of Mbuti and Biaka Pygmies, and not in a common ancestral population. Moreover, most Pygmy-like groups around the world dwell in tropical forests, and hence are likely to have iodine-deficient diets. The possibility that independent adaptations to an iodine-deficient diet might therefore have contributed to the convergent evolution of the short stature phenotype in Pygmy-like groups around the world deserves further investigation.
Source: Wikipedia contributors. “African Pygmies.” Wikipedia, The Free Encyclopedia. Wikipedia, The Free Encyclopedia, 22 Nov. 2018. Web. 26 Dec. 2018.