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View Full Version : Divergence between archaic and modern humans may date to 260,000 years ago.



Angela
22-01-20, 17:07
See:
https://www.biorxiv.org/content/10.1101/145409v1

Ancient genomes from southern Africa pushes modern human divergence beyond 260,000 years ago View ORCID Profile (http://orcid.org/0000-0002-8160-9621)Carina M. Schlebusch, View ORCID Profile (http://orcid.org/0000-0002-6456-8055)Helena Malmström, View ORCID Profile (http://orcid.org/0000-0001-9460-390X)Torsten Günther, Per Sjödin, Alexandra Coutinho, View ORCID Profile (http://orcid.org/0000-0003-3784-4285)Hanna Edlund, Arielle R. Munters, Maryna Steyn, View ORCID Profile (http://orcid.org/0000-0003-2488-9185)Himla Soodyall, View ORCID Profile (http://orcid.org/0000-0002-0675-0414)Marlize Lombard, View ORCID Profile (http://orcid.org/0000-0001-7840-7853)Mattias Jakobsson

"Southern Africa is consistently placed as one of the potential regions for the evolution of Homo sapiens. To examine the region’s human prehistory prior to the arrival of migrants from East and West Africa or Eurasia in the last 1,700 years, we generated and analyzed genome sequence data from seven ancient individuals from KwaZulu-Natal, South Africa. Three Stone Age hunter-gatherers date to ~2,000 years ago, and we show that they were related to current-day southern San groups such as the Karretjie People. Four Iron Age farmers (300–500 years old) have genetic signatures similar to present day Bantu-speakers. The genome sequence (13x coverage) of a juvenile boy from Ballito Bay, who lived ~2,000 years ago, demonstrates that southern African Stone Age hunter-gatherers were not impacted by recent admixture; however, we estimate that all modern-day Khoekhoe and San groups have been influenced by 9–22% genetic admixture from East African/Eurasian pastoralist groups arriving >1,000 years ago, including the Ju|‘hoansi San, previously thought to have very low levels of admixture. Using traditional and new approaches, we estimate the population divergence time between the Ballito Bay boy and other groups to beyond 260,000 years ago. These estimates dramatically increases the deepest divergence amongst modern humans, coincide with the onset of the Middle Stone Age in sub-Saharan Africa, and coincide with anatomical developments of archaic humans into modern humans as represented in the local fossil record. Cumulatively, cross-disciplinary records increasingly point to southern Africa as a potential (not necessarily exclusive) ‘hot spot’ for the evolution of our species."

bicicleur
22-01-20, 18:02
Basal S African contributed 86 % to KS
but even older Basal human contributed 31 % to Bantu

jose luis
23-01-20, 17:33
https://www.nature.com/articles/s41586-020-1929-1


Our knowledge of ancient human population structure in sub-Saharan Africa, particularly prior to the advent of food production, remains limited. Here we report genome-wide DNA data from four children—two of whom were buried approximately 8,000 years ago and two 3,000 years ago—from Shum Laka (Cameroon), one of the earliest known archaeological sites within the probable homeland of the Bantu language group. One individual carried the deeply divergent Y chromosome haplogroup A00, which today is found almost exclusively in the same region12,13. However, the genome-wide ancestry profiles of all four individuals are most similar to those of present-day hunter-gatherers from western Central Africa, which implies that populations in western Cameroon today—as well as speakers of Bantu languages from across the continent—are not descended substantially from the population represented by these four people. We infer an Africa-wide phylogeny that features widespread admixture and three prominent radiations, including one that gave rise to at least four major lineages deep in the history of modern humans.

Angela
23-01-20, 18:14
Hey, Jose, we already had a thread on this so I'm going to merge the threads.

jose luis
23-01-20, 20:19
Cool.

Where is the lotus flower without the swamp rot?

Angela
26-01-20, 22:34
Some interesting thoughts from Chris Stringer on the findings in the paper.

https://twitter.com/ChrisStringer65/status/1220046258976567298/photo/1

jose luis
07-04-20, 10:20
Human origin and migration deciphered from mitochondrial sequences

https://www.biorxiv.org/content/10.1101/848341v3

Abstract
The origin of modern human and their migration across the world is one of the most debated topics for the decades. There exist two different hypotheses, recent African origin and multi-regional evolution, based on the genomic studies, haplogroups, archaeological records, cultural behaviors, palaeontology studies, etc. Various studies placed the modern humans in a phylogenetic tree to depict the relationships among them. The debate for determining those regions of Africa which witnessed the first origin of humans still exists. The conflicts between the results obtained from the molecular data and the archaeological and palaeontological reports still exist. We adopt a novel genomic feature derived from the whole mitochondrial sequence, and using a novel distance function the phylogenetic trees are constructed based on the feature which provide a new insight on human migration. We propose a new method to derive the bootstrap replica from the genome sequences by considering the genetic variance to demonstrate the robustness of the obtained trees. The results derived from the genomic feature are more consistent with the archaeological findings based on the time of origin of different communities. We find that west and central African communities are placed at the basal point with a very high bootstrap score. This study roughly estimates the existence of the archaic human at 800-900 kilo years ago and presence of human in Africa at 600-700 kilo years ago. This supports the presence of an ancestor in the west and central Africa much earlier than that of the fossils identified.