Our A00 Cameroon Research Project is meant to discover the distribution of A00 and its diversity. Matthew Fomine Forka, a doctoral candidate at the U. of Yaounde 1, is traveling to a number of regions of Cameroon to gather DNA samples from a variety of ethnic groups. On his first field trip, to Mbo and Bangwa (Nweh) villages, he collected 204 samples. Astrid and Thomas Krahn's YSEQ lab has found that a total of 35 of them belong to A00! That means that of the 177 samples that have clear results, 19.77% are A00.
Matthew has just returned from his second field trip, sampling the Bamileke people, as well as some different Bangwa villages, to the north and south of their central Fontem area. This will give us evidence to see whether the A00 found among the Bangwa was shared with the Bamileke, and brought with the Bangwa founders to Lebialem, or was only present among the indigenous people, who in Bangwa legends are known as the Beketche, who were living in the hills of Lebialem when the Bangwa founders arrived.
We hope to discover greater diversity in the A00 from other parts of Cameroon. Our most ambitious trips are still to come. One will visit villages of the Banyangi and Ejagham peoples, in the western regions toward the Cross River Valley, closer to Nigeria. In the other trip, Matthew will seek out the communities of the Baka, Bakola (Gyele) and Bedzan forest peoples in the South and East of Cameroon.
In order to fulfill these dreams, we'll be needing your ongoing support. A new fundraiser will soon be launched, but until then, we will gratefully accept your contributions at the Ancient Roots Research PayPal page:
An African American Paternal Lineage Adds an Extremely Ancient Root to the Human Y Chromosome Phylogenetic Tree 2013
Fernando L. Mendez,1 Thomas Krahn,2 Bonnie Schrack,2 Astrid-Maria Krahn,2 Krishna R. Veeramah,1 August E. Woerner,1 Forka Leypey Mathew Fomine,3 Neil Bradman,4 Mark G. Thomas,5 Tatiana M. Karafet,1 and Michael F. Hammer1,*
We report the discovery of an African American Y chromosome that carries the ancestral state of all SNPs that defined the basal portion of the Y chromosome phylogenetic tree. We sequenced ~240 kb of this chromosome to identify private, derived mutations on this lineage, which we named A00. We then estimated the time to the most recent common ancestor (TMRCA) for the Y tree as 338 thousand years ago (kya) (95% confidence interval 1⁄4 237–581 kya). Remarkably, this exceeds current estimates of the mtDNA TMRCA, as well as those of the age of the oldest anatomically modern human fossils. The extremely ancient age combined with the rarity of the A00 lineage, which we also find at very low frequency in central Africa, point to the importance of considering more complex models for the origin of Y chromosome diversity. These models include ancient population structure and the possibility of archaic introgression of Y chromo- somes into anatomically modern humans. The A00 lineage was discovered in a large database of consumer samples of African Americans and has not been identified in traditional hunter-gatherer populations from sub-Saharan Africa. This underscores how the stochastic nature of the genealogical process can affect inference from a single locus and warrants caution during the interpretation of the geographic location of divergent branches of the Y chromosome phylogenetic tree for the elucidation of human origins.
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the lioness, Is it plausible that this YDNA sequence could have come from the ghost population which shows up in Baka & Bacola pygmies (West Africa) but not in eastern Pymies (Mbuti)?
Aside, in the photo, is the red flying thing a butterfly, a hang glider or a UFO?
quote:Originally posted by DD'eDeN: [QB] the lioness, Is it plausible that this YDNA sequence could have come from the ghost population which shows up in Baka & Bacola pygmies (West Africa) but not in eastern Pymies (Mbuti)?
I don't know about ghost population of them
quote:Originally posted by DD'eDeN: Aside, in the photo, is the red flying thing a butterfly, a hang glider or a UFO?
Hard to tell, I am going to guess a kite unless there's a Cameroon butterfly with those colors.
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"Some Pygmy women, after having sex with a Bantu man, have given birth to half-Bantu babies, a phenomenon that integrates Bantu genes into the Pygmy population." [False, the children stay with the Bantu villagers]
"These women and their offspring stay in the Pygmy village," [Pygmies had no villages, they had nomadic camps; Bantus always had agricultural villages] "and so don't mix with the Bantu."
It seems that EVERY article about Pygmies claims Pygmies shrank. Not a single exception. It is fiction, pretending to be science.
Pygmies, Okapi short-necked giraffes and forest elephants all live in the Ituri rainforest, and are genetically generalized ancestral to tall people, long-necked giraffes and non-forest elephants all of which then evolved in open space environments.
Razib Khan: In other words, the agriculturalists are the outgroup to the Pygmies, and Pygmies are a phylogenetically supported group, though one with two branches. This does not prove that Pygmy stature is necessarily a common derived feature inherited from the ancestral population, for that you would need to look closely at the genetic architecture of the trait in question and the phylogeny of the haplotypes on the implicated loci. In any case the second set of Structure results are filtered for individuals with less than 20% admixture, and so the between group differences are even starker. It seems likely then that whatever the origin of the Pygmy phenotype, they are the descendants of the pre-Bantu substrate which was extant across Central Africa before the great expansion, and these pre-Bantu populations had a common ancestry. http://blogs.discovermagazine.com/gnxp/2009/04/the-ancient-origins-of-african-pygmies/#.WYdl1JqFOJB
…finding that the ancestors of AGR and PYG populations diverged ca. 60 Kya is consistent with our recent single-locus estimation based on the mtDNA diversity of African farmers and Western Pygmies…Most of the large waves of population expansion and migration, both within and out of Africa, have been dated at ca. 50-80 Kya, based on several genetic markers…It has been suggested that these early population movements within and out of Africa may have been triggered by rapid environmental changes. During this period, sub-Saharan Africa witnessed a major episode of climatic change: a sharp oscillation towards a drier climate, with annual rainfall decreasing by up to 50%…In this context, our estimated date of the initial divergence between the ancestors of present-day farmers and Pygmies implies that this period was characterized not only by major human movements, but also by early episodes of population differentiation within the African continent. Our evidence for a separation of the ancestors of Western and Eastern Pygmy groups ca. 20 Kya is also consistent with a previous mtDNA study, dating the time of separation of these two Pygmy groups to at least 18 Kya…These estimates coincide with another period of major climatic change, the Last Glacial Maximum, which led to a massive retreat of tropical forests in Central Africa…Our genetic results thus support the anthropological hypothesis that the ancestors of present-day forest specialists — Western and Eastern Pygmies — began to diverge at the same time as the rainforest retreated into refugia, ~20 Kya…Finally, our estimates of gene flow between each group of Pygmies and agricultural populations yielded contrasting values, with levels of gene flow between WPYG and AGR populations three to seven times higher than those between EPYG and AGR populations… . These data suggest the intriguing possibility that concurrently with the Out of Africa event the seeds for the structure in modern African populations was already being laid. No doubt there were many populations between the ancestors of the Bantus and the Pygmies whom they enveloped, but as I suggest above it may be that the Pygmy groups we see are trivial remnants of the extant populations which were pushed aside by the agriculturalists as they expanded. The Western and Eastern Pygmies may have had the good luck to be in close proximity to ecological domains where their lifestyle was at a comparative advantage and so were able to maintain some sort of demographic and population genetic integrity in the face of the agricultural onslaught. Ergo, the genetic discontinuity might be an outcome of these details of history, as the groups which span the gap between the proto-Bantu and the Pygmies left very few descendants. I wonder therefore the need to appeal to refugia ~20,000 years ago, as opposed to the Western and Eastern Pygmy simply being the western and eastern edges of a continuous population of which they are the last fragments. I do know that there are data which suggest that the speciation of some African monkeys is a function of the fragmentation of the rainforest during the Last Glacial Maximum, but most monkeys are by nature forest animals, while humans are not. Therefore I am skeptical of the thesis that ecological fragmentation is the reason behind the genetic differences between the two Pygmy groups dating to ~20,000 before the present. Much more likely that the Pygmy populations retreated to regions where hunter-gathering was still viable, and their genetic distance is simply an echo of population structure since erased by the Bantu demographic expansion. On the other hand, if subsequent data showed that the Pygmy phenotype is of very ancient pedigree, then perhaps the concept of perpetually forest resident populations might seem more plausible.
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