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41d3NIUbD8L._SY344_BO1,204,203,200_ Southern Africa is kind of a big deal. Not because it is the seat of human origins; I am beginning to think that question is “not even wrong.” Nor because it contains the “oldest human population” in the world; we are all the oldest human population in the world. Rather, the genetic variation one can find across a small region in southern Africa is incredible, and, it is one of the few regions of the world where hunter-gatherers have persisted in a culturally pristine fashion. By this, I mean that there is no evidence that the hunter-gatherers of southern Africa practiced another way of life (i.e., that they are marginalized agriculturalists or nomads), or, that their language was adopted from agriculturalists (as is the case with the Pygmies of central Africa). In other words, the continuity of the peoples of southern Africa is more notable not for their genetics, but their culture. That being said, the cultural conditions under which the KhoeSan peoples existed are of genetic interest, because their high degree of variation may reflect aspects of population dynamics common to hunter-gatherers as a whole.

In light of all this a new preprint on bioarxiv is quite interesting, Fine-scale human population structure in southern Africa reflects ecological boundaries. The title rather says it all, but I’ll admit that it’s hard to keep track of all the populations. It certainly strikes me as plausible, as the genetics suggests that there’s a lot of structure that built up over the years. Of note: “To contrast this with Europeans, the ≠Khomani and the Ju/’hoansi may have diverged over 30,000 ya but live only 1,000 km apart, roughly the equivalent distance between Switzerland and Denmark whose populations have little genetic divergence.” They report trans-Kalahari F st values on the order of 0.05, which is quite high, on an order of magnitude or so greater than what can be found in Northern Europe. But the latter is more comprehensible when you consider the genetic character of the North European plain only arrived at its current state ~4,000 years ago.

Adam Kok III, last of the Griqua captains

Adam Kok III, last of the Griqua captains

Since the above is a preprint, some critiques are in order. The authors use ancestry tract lengths to assess admixture of Bantu, Asian, and European, elements into the KhoeSan. The implication is that these were separate admixture events. Some of them certainly were. But I’m a little skeptical of the power of these methods to distinguish admixture between the last two non-African components (also, I think it is probably advised for a population genetics paper to dispense with the cultural construct of Asian and make the clear distinction between South and East Asians, since the former are often genetically closer to Europeans, and this previously inflated the European proportion among Cape Coloureds). It’s been many years since I read A History of South Africa, but one of the more interesting aspects that I recall from this book was the cultural distinctiveness of what has now come to be called the Cape Coloured people, and their role as mediators along a fluid cultural frontier with the KhoeSan people. The history of the Griqua in particular shed light on how one might imagine European and Asian (South and East) ancestry arrived into the KhoeSan. Though racially mixed, the Griqua resembled the Dutch in formal and institutional aspects of their culture by the 19th century. But, as a semi-nomadic and pastoralist group they also had affinities with their African neighbors (and often, they played the role of predators with the Africans and their herds), with whom they clearly shared ancestry. It was not an unknown phenomenon to have Griqua scouts “go home to their mother’s people.” Even if their literal mother was also a Griqua, they seem to have had a sense that their maternal ancestors were invariably non-European, and often derived from the KhoeSan (many Griqua still spoke the now extinct Cape Khoi language, though they were shifting toward a Dutch Creole). The probability of assimilation of unadmixed Europeans, South Asians, and East Asians, into KhoeSan groups is not zero, but it strikes me as quite low. On the other hand, Griqua, who were mixed between all the populations of southern Africa, and culturally quite at home in the semi-desert wilderness, seem ideal candidates for the population which could serve as the vectors for transmission of these ancestral elements into the KhoeSan.

A second issue with this preprint is that I’d like to see more methods. E.g., three and four-population tests and TreeMix in particular, since with 320,000 SNPs these should be totally feasible with genotype data. These are not groups that most people have much familiar with, so PCA and ADMIXTURE tend to overwhelm. To develop a decent intuition about what’s going on trees and tables are often helpful (I don’t like tables usually, but often when you are focusing on a finite number of populations per row they can allow for greater focus). Also, there are now interesting ways to analyze spatial genetics beyond Mantel tests.

Ultimately these results confirm what I already held as a prior. It strikes me that the relationship we see between language and genes today is largely a function of the reality that much of the population genetic structure we see around us is a recent phenomenon. That is, massive migrations due to cultural changes (e.g., agriculture) were accompanied by both language and genes, and only a few thousand years are simply not enough time to allow for linguistic differentiation to obscure common origins. In contrast, if, as seems plausible, many of the KhoeSan people were resident in southern Africa for tens of thousands of years, then correlations between language and genes should slowly decouple (in part because deep linguistic affinities may not be discernible). That being said, I would not be surprised if ancient DNA from southern Africa at some point overturns conventional wisdom that these peoples are truly primal….

 
• Category: Science • Tags: Genetics, South Africa 
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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.

First, the methodology. I took the Gujaratis, Utah whites, Chinese from Denver, and Luhya (Bantu) from Kenya, and merged them with the Bushmen from the Henn et al. thick-marker data set. I also decided to add in the Yemeni Jews from Behar et al., mostly to check that the West Eurasian ancestry of the Cape Coloureds was in fact Northern European. I limited the Gujarati sample to those from “Gujarati_B”, which is the “more South Asian” cluster within the HapMap data set. I also reduced the numbers for a lot of HapMap populations. I’m looking at inter-continental differences, so I assumed that N of ~20 would suffice. After merging these data sets with the Cape Coloured samples I pruned all the missing SNPs. This left me with ~230,000 markers. In my experience this is kind of overkill for ADMIXTURE at this level of genetic distance between the hypothetical parent populations, but better safe than sorry. I also ran the samples through EIGENSOFT to generate PCAs. Also know that I performed a few “trials” with Sandawe and Hadza from Henn et. al., as well as with larger samples from the HapMap. That either added nothing on the margin, or just got confusing (there’s not really too much Sandawe and Hadza in the Cape Coloureds beyond what the Bantu must have picked up).

After I ran ADMIXTURE up to K = 7 it was clear that the optimal point in terms of informativeness was K = 6. You can see that the Cape Coloured samples have Northern European, Khoisan, Bantu African, Indian, and East Asian ancestry. There is a Yemeni component in two of the Coloured individuals which begs to be explained. This component is too high to be explained by Northern European ancestry alone. It could be explained by slaves from the Muslim Arab world. Also, the Indian reference sample used here was pruned to be very homogeneous. The slaves from South Asia were almost certainly much more diverse than the Gujarati_B population, which is mostly a group of Patels. Finally, sometimes when you run ADMIXTURE you see that combinations of atypical genetic backgrounds (e.g., Khoisan + Chinese) can general components which are likely artifacts. This tends to be an issue when you have two components which aren’t normally found together, and one is at a far lower level than the other. I’ve noticed this in particular with people with low amounts of Sub-Saharan African ancestry and Eurasian genetic backgrounds. They often come out to be East African or Pygmy or Bushmen when the probability of this is likely to be very low a priori. Notice that a few of the Bushmen have the Yemeni component but nothing else besides what you’d expect. This to me increases the likely that the light green in the Coloureds is also an artifact of the Khoisan genetic background against one of the other components.

So below is the K = 6 ADMIXTURE plot, along with the informative PCA’s. Observe that the three Coloureds have IDs.

Image Credit: Wikimedia Commons.

(Republished from Discover/GNXP by permission of author or representative)
 
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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:

It is often assumed that Afrikaners stem from a small number of Dutch immigrants. As a result they should be genetically homogeneous, show founder effects and be rather inbred. By disentangling my own South African pedigree, that is on average 12 generations deep, I try to quantify the genetic heritage of an Afrikaner. As much as 6% of my genes have been contributed by slaves from Africa, Madagascar and India, and a woman from China. This figure compares well to other genetic and genealogical estimates. Seventy three percent of my lineages coalesce into common founders, and I am related in excess of 10 times to 20 founder ancestors (30 times to Willem Schalk van der Merwe). Significant founder effects are thus possible. The overrepresentation of certain founder ancestors is in part explained by the fact that they had more children. This is remarkable given that they lived more than 300 years (or 12 generations) ago. DECONSTRUCT, a new program for pedigree analysis, identified 125 common ancestors in my pedigree. However, these common ancestors are so distant from myself, paths of between 16 and 25 steps in length, that my inbreeding coefficient is not unusually high (f approximately 0.0019).

Inbreeding coefficient is the probability that one’s two alleles are identical by descent. That is, they come from the same individual. For example, in the case of Elisabeth Fritzl her children have many genes where the alleles are identical by descent because half of her own genes are from her father, some many of his alleles will come back to reside within the same individual as part of a diploid pair. J. M. Greef notes that his inbreeding coefficient is about twice as high as is the norm for the typical European. Europe is a region of relatively low consanguinity, so this is a stringent reference. In some populations the inbreeding coefficient can be as high as 0.01. In short, he’s not too inbred.

That being said, the data within his pedigree do seem to show disproportionate contribution by some ancestors. This makes sense for two primary reasons. First, some component of reproductive variance is random (often modeled as a poisson distribution). Second, some component of reproductive variance is due to innate fitness (e.g., the Genghis Khan Y haplotype may be a case of this). Equality of contribution just isn’t in the cards.

Figure 2 shows the distribution of relationships within the pedigree:
nf2

Panel a illustrates that one individual is an ancestor of the author 30 times over! Many individuals are ancestors only once. Panel b shows relatedness, and again, some individuals are much closer to the author than others, with a skewed distribution. Panel c shows the number of generations between the ancestor and the author. The median number is well above ten generations, so the author has deep roots in South Africa. Finally, panel d shows the number of steps between his parents for any given ancestor. Because the author’s parents are both Afrikaners they share many common ancestors, but the steps between seem relatively large, and confirms that the author is not particularly inbred (if the parents were first cousins naturally there would be much shorter steps to common ancestors). It is clear disproportionate amount of J. M. Greef’s genes come from early settlers. This makes sense insofar as demographic expansion was likely front loaded, with later settlers having less of a chance to make an impact on an already large population.

The following table shows the contribution by various European and non-European groups to the author’s ancestry, as well as estimates for the total Afrikaner population in earlier studies on the right.

afrikgen

Note one point: only a minority of the ancestry of the author and Afrikaners are ethnically Dutch. This is important, because it shows how culture can spread and overwhelm ancestry. The Dutch imposed their language upon the French Huguenots, and their religion upon the Germans (who I presume were mostly Lutheran if they were from northern Germany, though a minority were Reformed or Catholic surely). Obviously the Reformed Calvinist religion and Afrikaans language both have a unique stamp in South Africa, but the connection of the Afrikaners to the Netherlands remained profound rather late in history. The Prime Minister of South Africa from 1958-1966 was born in the Netherlands. And yet another fact hard to deny is that the Huguenot French component seems to have persevered to a greater extent culturally than the German. The last Afrikaner President was named F. W. de Klerk, his surname being a form of Le Clerc. Another prominent South African head of state was Daniel Francois Malan. The author observes:

It is not clear if my higher estimate of French contribution is because of a systematic mistake in Heese’s (1970) estimate, or if it is because of a quirkiness in my own ancestry. It seemed to be the case that when a lineage hit the French Huguenots it stayed in this group. It will be interesting to compare the degree of inbreeding of the early generations of Huguenots to the other early immigrants. In the light of the calculations of Heyer et al. (2005) there is an interesting possibility that the cultural inheritance of fitness may have led to a systematic bias in Afrikaners, since Huguenots tended to be more educated and trained than German emigrants who tended to be soldiers. We are currently investigating this hypothesis.

There is a joke that the Baltic possessions of the Swedish monarchy were conquered with Finnish soldiers. Similarly, the Dutch overseas colonial possessions were staffed, especially at a lower level, by the rural male population surplus of northern Germany. A great many of these, likely the vast majority, never returned home and died abroad. These men contributed greatly to the census size of the Afrikaner population during much of its history, but it seems plausible that their fitness was far lower than the established Dutch and Huguenot groups because they lacked the resources and capital to flourish in a world which was much closer to the Malthusian edge than today. Many people don’t leave descendants, and it seems plausible that these Germans were fated not to do so to a far greater extent than the Dutch and Huguenots whom they were employed to protect and serve. Because of the genetic closeness of the north German and Dutch populations (in reality, Dutch are really simply another group of north Germans who transformed their regional identity into a national one for various reasons) I doubt that more thorough genetic testing will resolve this, rather, more pedigree analysis needs to be done on other individuals. But it’s an insight into the fact that social parameters have often been crucial to fitness in the human past.

As for the non-white component, the author’s results match those of previous researchers. He confirmed the likely probability of these results by the fact that his father carries mtDNA group M, which is most diverse in India. And in fact his father’s maternal lineage does trace back to a woman who was likely an Indian slave (slave women had particular surnames indicating their origin). My previous posts on the Coloureds highlighted the large Asiatic component to their ancestry, and it looks like previous researchers ignored this and focused on the Khoisan and Bantu. They also attempted to calculate ancestry based on classical markers which were found in African populations, and are present in low frequencies in Afrikaners, but that might ignore Asian signature markers (additionally, I assume that there was some natural selection for G6PD alleles). A survey of the total genomes of Afrikaners should be able to resolve the details of their ancestry, but it seems that the Afrikaners are far more colored than white Americans, by a factor of 5, but far less than white Latin Americans like Argentineans, probably by a factor of 5.

Finally, the author was also able to assess whether his ancestors exhibited a trade between quantity and quality in terms of their optimal number of offspring. In other words, did those who favored an extreme r or K selected strategy suffer vis-a-vis those who produced a more moderate number of offspring, not too low, and not too high? The author did not find any evidence of a tradeoff, and an optimal fitness. He was careful not to generalize too much, especially in light of the fact that Dutch colonial South Africa was an atypical society in many ways. I assume that living on the frontier means not having to say you’re sorry if you breed too much or too little.

Citation: Greeff, J. (2007). Deconstructing Jaco: Genetic Heritage of an Afrikaner Annals of Human Genetics, 71 (5), 674-688 DOI: 10.1111/j.1469-1809.2007.00363.x

(Republished from Discover/GNXP by permission of author or representative)
 
• Category: Science • Tags: Afrikaner, Anthropology, Genetics, South Africa 
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cape1Several 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:

The study of recently admixed populations provides unique tools for understanding recent population dynamics, socio-cultural factors associated with the founding of emerging populations, and the genetic basis of disease by means of admixture mapping. Historical records and recent autosomal data indicate that the South African Coloured population forms a unique highly admixed population, resulting from the encounter of different peoples from Africa, Europe, and Asia. However, little is known about the mode by which this admixed population was recently founded. Here we show, through detailed phylogeographic analyses of mitochondrial DNA and Y-chromosome variation in a large sample of South African Coloured individuals, that this population derives from at least five different parental populations (Khoisan, Bantus, Europeans, Indians, and Southeast Asians), who have differently contributed to the foundation of the South African Coloured. In addition, our analyses reveal extraordinarily unbalanced gender-specific contributions of the various population genetic components, the most striking being the massive maternal contribution of Khoisan peoples (more than 60%) and the almost negligible maternal contribution of Europeans with respect to their paternal counterparts. The overall picture of gender-biased admixture depicted in this study indicates that the modern South African Coloured population results mainly from the early encounter of European and African males with autochthonous Khoisan females of the Cape of Good Hope around 350 years ago.

The main results are in figure 2 & 3. The top left panel shows the mtDNA variation on an MDS chart in relation to other populations, “SAC” = South African Coloureds. The bottom left panel shows NRY variation. And the right panel shows the estimated admixture for mtDNA and NRY by population.

cape4

The results are rather clear, excepting the difference between the MDS and admixture estimates which seem to place less weight on the Bantu component in the second than the former. The authors chalk this up to difficulties distinguishing the Khoisan from the “pan-African” component. Contemporary Khoisan show substantial overlap with Bantu groups (just as some Bantu groups in South Africa such as the Xhosa show a great deal of Khoisan ancestry), so there are some ambiguities in assigning a haplogroup to one population or the other (the overlap seems a product of recent admixture).

But be as that may be, it is clear that a major dynamic in the founding of the Cape Coloureds had to be the pairing of Khoisan females with non-Khoisan males. The disjunction between European ancestry on the male and female lineages is stark, but should not be surprising in light of what we know from colonial history. And perhaps not just the colonial history of South Africa. The same pattern is evident in Latin America. Even societies which have transitioned from Mestizo to white, such as Argentina, seem to have done so through generations of male biased migration so that the indigenous mtDNA remains. And the same pattern can be found in some cases where we have no historical documentation because ethnogenesis occurred during the prehistorical period. In particular this seems the case in India, where male lineages show a strong West Eurasian bias, while female lineages do not (they are more closely related to East Eurasian lineages, though that connection is much more distant than Indian West Eurasia lineages have with other West Eurasian lineages).

A little over 10 years ago L. L. Cavalli-Sforza was coauthor on a paper titled Genetic evidence for a higher female migration rate in humans. The logic behind the results are simple, most human societies are patrilocal, so one presumes that gene flow would be mediated by the movement of women between local groups. Cavalli-Sforza found that female lineages seemed to be less localized than male lineages, implying greater gene flow. The literature since then seems rather muddled, and has not confirmed this original finding in a solid manner. I suspect that this is because one general dynamic can not capture the varied events which have characterized human genetic history. That is, there were periodic “shocks” to the basic patterns of worldwide genetic variation, but after those shocks passed then the dynamics which Cavalli-Sforza saw would come to the fore. Exploring the details of the balance between these varied forces is going to be where the future avenues of research lay. I predict that it is going to be in regions and populations which have gone through great cultural ferment since the last Ice Age that you will see this palimpsest whereby variation emerged as a synthesis of shocks interleaved between long periods of stasis and more conventional deme-to-deme gene flow. By contrast, isolated hunter-gatherer populations such as the Andaman Islanders may have missed out on the shocks, the period of “genetic revolutions” (though as I imply above, most hunter-gatherer populations show a great deal of admixture with the far more numerous agricultures who marginalize them and push up against their range, as is in the case among the Bushmen).

Finally, going back to South Africa one major issue is going to be the nature of the Afrikaners. Tentative earlier genetic and genealogical work suggests that ~5% of their ancestry is non-European, probably reflecting the movement of Cape Coloureds who could pass as white into the Afrikaner population (Cape Coloureds usually share language and religion with Afrikaners, so the cultural move would not have been insurmountable). Yet I have seen very few papers such as this, Deconstructing Jaco: genetic heritage of an Afrikaner. The author concludes that ~6% of his ancestry is from non-white slaves, in line with prior expectations. Though white Americans often take pride in their Native American ancestry (often genealogically attested, as with the descendants of Pocahontas) the total proportions are actually rather small, probably on the order of ~1% at most. In contrast the Afrikaners likely have more non-white ancestry because their founding population did not receive as much migration from Europe to dilute the original non-European element.

Addendum: The Cape Coloureds seem a real interesting population in light of admixture mapping, no?

Citation: Quintana-Murci, L., Harmant, C., Quach, H., Balanovsky, O., Zaporozhchenko, V., Bormans, C., van Helden, P., Hoal, E., & Behar, D. (2010). Strong Maternal Khoisan Contribution to the South African Coloured Population: A Case of Gender-Biased Admixture The American Journal of Human Genetics, 86 (4), 611-620 DOI: 10.1016/j.ajhg.2010.02.014

(Republished from Discover/GNXP by permission of author or representative)
 
• Category: Science • Tags: Cape Coloureds, Culture, Genetics, South Africa 
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Razib Khan
About Razib Khan

"I have degrees in biology and biochemistry, a passion for genetics, history, and philosophy, and shrimp is my favorite food. If you want to know more, see the links at http://www.razib.com"