A Cape Coloured family
I’ve mentioned the Cape Coloureds of South Africa on this weblog before. Culturally they’re Afrikaans in language and Dutch Reformed in religion (the possibly related Cape Malay group is Muslim, though also Afrikaans speaking traditionally). But racially they’re a very diverse lot. In this way they can be analogized to black Americans, who are about ~75% West African and ~25% Northern European, with the variance in ancestral proportions being such that ~10% are ~50% or more European in ancestry. The Cape Coloureds though are much more complex. Some of their ancestry is almost certainly Bantu African. This element is related to the West African affinities of black Americans. And, they have a Northern European element, which likely came in via the Dutch, German, and Huguenot settlers (mostly males). But the Cape Coloureds also have other contributions to their genetic heritage. Firstly, they have Khoisan ancestry, whether from Bushmen or Khoi. This is well known in their oral memory. The the hinterlands of the Cape of Good Hope are beyond the ecological range of the Bantu agricultural toolkit, so the region was still dominated by the Khoisan when the Europeans arrived. But there are also other suggestions of ancestry from Asia. The existence of the Cape Malays, whose adherence to Islam derives from the Muslims slaves brought by the Dutch, hints at likely relationships to the populations of maritime Southeast Asia. Finally, there are the Indians. This element is not too well recalled in cultural memory. But the Dutch brought many slaves from India as well as Southeast Asia. The Dutch first governor of the Cape Colony had a maternal grandmother who was an Indian slave, by various accounts Goan or Bengali (the town of Stellensbosch is named for him). No doubt it was far more likely that the usual lot of the descendants of Indian slaves during the Dutch era would be to be absorbed into the melange of the Coloured population than assimilated into what later became the Afrikaners.
Why is this aspect of Cape Coloured ancestry forgotten? I think part of the reason is that there is a large South African Indian community present today, but that community post-dates the Dutch period, and arrived with the British. When South Africans think of Indians they think of these people. Interestingly when the new genetic studies confirming Indian ancestry came on the scene I was “corrected” several times by Indians themselves when reporting this part of the Coloured heritage. They were under the impression I must be mistaken, as no one was familiar with the Cape Coloureds having Indian ancestry. Unfortunately pointing to PCA and STRUCTURE plots did not clear up the confusion.
In any case, thanks to the African Ancestry Project I now have three unrelated Coloured samples (I have more, but they are related). Since AAP is Afrocentric I thought it would be appropriate to run the Coloured samples separate first. So that’s what I did.
A few weeks ago I reviewed a paper on the the genetics of the Cape Coloured population. Within it there was a refrence to another paper, Deconstructing Jaco: genetic heritage of an Afrikaner. The title refers to the author himself. It was an analysis of his own pedigree going back to the 17th century, along with his mtDNA, his father’s mtDNA, and his Y lineage. The genetics is a bit thin, but the pedigree information is of Scandinavian quality from what I can tell. Praised the records of the Reformed Church!
The author’s utilizes an inversion of the typical method whereby a survey of a population may give some insight into individuals within that population. Rather, he leverages the thorough church records of his Afrikaner community, and his local roots, to paint a picture of his own ancestry. Then he compares the results to those of the community as a whole. Though an N of 1 certainly has limits it seems that the author concludes that he is relatively representative because some of the statistics that emerge out of pedigree analysis seem to fall in line with what genealogists working with the whole community have found. Additionally, it is clearly that he has deep roots within the historic Afrikaner nation, so assuming random mating and little population substructure, inferences from his pedigree may have some general utility.
Afrikaners apparently have some peculiarities genetically which has made them of some interest to scientists. It turns out that they seem to exhibit high frequencies of classical Mendelian diseases, a hallmark of inbreeding or population bottlenecks. This aligns well with the thesis that Afrikaners are the descendants of a small group of founders who arrived in the 17th century and entered into a long phase of demographic expansion, which culminated with their long Trek into the veld to escape English domination as well as perpetuate their practice of slavery (James Michner’s The Covenant is a fictionalization of this). As I have observed before the primacy of the “first settler” seems to loom large in the minds of demographers.
J. M. Greef, the author of the above paper, seems to refute this simple story in his own genealogy, though not the core aspect of the importance of the first founders. First the abstract:
Several months ago I put up a post which reviewed the geographical connections within the total genome content of the Cape Coloureds of South Africa. These peoples (plural because distinctive ethnic groups such as the Griqua were subsumed into this category in the 20th century) are of diverse origin, though generally their African and European ancestry has been highlighted. To the left I’ve reedited a plot which illustrates the inferred proportion of ancestry from various groups in modern Cape Coloured populations. Note that there is a substantial proportion of Asian ancestry, both South and East Asian. This makes historical sense as during the period of the founding of the Cape Colony a substantial number of Southeast and South Asian slaves were transferred from the Dutch East Indies, as well as from Madagascar, which itself has a Southeast Asian component in its population. Additionally, observe that the Bushmen & Khoikhoi element has been separated from the Bantu element. Archaeologists assume that the former are indigenous to South Africa, while the latter arrived within the last 2,000 years as the edge of the Bantu expansion which swept out of Nigeria east and south. These two populations are obviously both African, but their common ancestry is very deep. In some phylogenies Bushmen may be represented as the outgroup to all other human lineages, implying that one has to go very far back indeed for a common ancestor. In other words, the Bushmen are not the “oldest” human population, but have the oldest point of common ancestry with other human populations (e.g., the last common ancestor between a European and an East Asian may be ~30,000 years ago, but that between a Bushmen and a European may be ~80,000 years ago).
But these studies do not tell us everything about the demographic history behind the ethnogenesis of the Cape Coloureds. In this case uniparental lineages, mtDNA which traces the matriline and and nonrecombinant Y chromosomes (NRY) which trace the patriline may offer some value. Unfortunately too often because of methodological considerations we have looked at the uniparental lineages first, and then the total genome content, which I think inverts the optimal order in terms of putting genetic findings in context. A new study focuses on the Cape Coloured mtDNA and NRY lineages, with the previous findings in mind, Strong maternal Khoisan contribution to the South African coloured population: a case of gender-biased admixture: