What they found surpassed their expectations: All the hunter-gatherer populations showed a strong signal of selection within a short stretch of DNA on chromosome 8, and all the agriculturalists lacked this signal. This genetic region helps regulate a gene called TRPS1, which plays an important role in skeletal development. That suggests natural selection specifically favored short stature in this group, the authors say.
citing https://pubmed.ncbi.nlm.nih.gov/31402299/
We find evidence for a strong, shared selective sweep among all hunter-gatherer groups in the regulatory region of TRPS1-primarily involved in morphological traits. We detect strong signals of polygenic adaptation for height
A Strong, Shared Selective Sweep at TRPS1 across All
Hunter-Gatherer Groups
This region lies upstream of the 50 UTR of TRPS1, which encodes
a transcription factor (TF) with multiple pleiotropic effects,
including skeletal development and inflammatory TH17 cell differentiation
[35–37].
These findings suggest
that the most robust signal of adaptation to the African rainforest
can be ascribed to TRPS1, possibly in relation with variation in
morphological and/or immunological traits.
In doing so, we found
evidence of a unique, strong sweep that is shared by all RHG
groups, targeting the regulatory region of TRPS1, mutations in
which can cause growth retardation, distinctive craniofacial features
[63], and hypertrichosis [64].
Interestingly, TRPS1 has been recently shown
to carry signals of archaic introgression in western Africans [68].
Functional studies should help determine the adaptive nature—
developmental and/or immune-related—of variation at this
locus, which possibly introgressed from extinct African hominins
[18, 68, 69].
So we know this gene is from the West African "archaic" ghost species....
yes Europeans had darker skin like the San Bushmen people - our original human culture - when the european diet was hunting and fishing - then the vitamin D was from the fatty organs of the fish and liver, etc. West Africans are taller due to an archaic homo sapien similar to neanderthals - they call it the "ghost" archaic homo lineages. Researchers suggest DNA from this group makes up between 2% and 19% of modern West Africans' genetic ancestry. They believe the interbreeding occurred ...
A mysterious but well-preserved hominid skull found nearly a century ago comes from a population that lived in Africa around 300,000 years ago, as the earliest Homo sapiens were evolving, a new study finds. The result suggests that later Middle Pleistocene Africa contained multiple contemporaneous hominin lineages (that is, Homo sapiens8,9, H. heidelbergensis/H. rhodesiensis and Homo naledi10,11), similar to Eurasia, where Homo neanderthalensis, the Denisovans, Homo floresiensis,Homo luzonensisand perhaps also Homo heidelbergensis and Homo erectus12 were found contemporaneously. the super-archaics were in the first wave of hominids who left Africa,” Rogers says. ...
genomes of 405 people from four subpopulations in West Africa that ... "Neanderthals are hominids in the genus Homo, humans, and generally classified as a distinct species, H. neanderthalensis, though sometimes as a subspecies of modern human as H. sapiens neanderthalensis" West Africans are 6% of this "ghost" Homo on average - more so than any other ethnicity. "although a pair of researchers recently reported in PLOS Genetics that humans in Africa interbred with another ancient hominin group both before and after the ancestors of European and Asian populations split off and migrated away. By the scientists’ estimates, DNA from that unknown group now makes up somewhere between 4% and 8% of modern human ancestry."
New research suggests that early humans in Africa interbred with a ghost population that likely split from the ancestors of humans and Neanderthals between 360,000 and 1.02 million years ago. this research suggests there were geographically diverse groups in Africa well before the main expansion out of the continent. And many of these groups will have contributed to the ancestry of people alive in Africa today. there may also have been gene-flow into the ancestors of West Africans directly from a mysterious archaic hominin. 6%-7% of the genomes of West Africans is archaic in origin. But this archaic ancestry wasn’t Neanderthal or Denisovan. Their model suggested the additional ancestry came from an archaic population for which we don’t currently have a genome. We examined the frequencies of archaic segments to investigate whether natural selection could have shaped the distribution of archaic alleles.... these populations derive 2 to 19% of their genetic ancestry from an archaic population that diverged before the split of Neanderthals and modern humans. TRPS1, a gene associated with trichorhinophalangeal syndrome (71% in YRI, 75% in MSL; Table 1). Pleiotropy (unusually tall height is from TRPS1) We find that, consistent with the recent finding of Meyer et al. (2012), Neanderthals contributed more DNA to modern East Asians than to modern Europeans. ...
the genomes of Yoruba people from Ibadan, Nigeria. They found more instances of genetic variation in the ancient segments than are seen in Neanderthal and Denisovan genes, suggesting that neither of these groups of ancient humans were the source of the genomic variance. Similar patterns were seen in the genomes of Mende people in Sierra Leone, Esan people in Nigeria and those in western areas of Gambia. The four populations are estimated to derive between 2 and 19 per cent of their ancestry from an archaic group of genes. They conclude that the ancestors of Neanderthals and Denisovans—whom they call Neandersovans—interbred with a “super-archaic” population that separated from other humans about 2 million years ago.
Likely candidates include early members of our genus, such as H. erectus or one of its contemporaries. The mixing likely happened outside of Africa, because that’s where both Neanderthals and Denisovans emerged, and it could have taken place at least 600,000 years ago. Mysterious ‘ghost’ populations had multiple trysts with human ancestors Whether the ghost hominin from West Africa and the superarchaic hominin that Rogers and his colleagues found are one and the same is unclear, but Rogers is keen to find out.
https://elixirfield.blogspot.com/2020/05/the-tyranny-of-genome-and-our-missing.html
Wow so I had it turned around - the Farmers are taller since they no longer live in the rainforest - but the San Bushmen are shorter from this rainforest adaptation.
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