Basal Eurasian
Basal-Eurasian is a hypothetical lineage of anatomically modern humans in the Middle East, linked to early West-Eurasians, without or less archaic admixture,[1][2] than compared to "eastern non-Africans", and which appear to have contributed to various West-Eurasian groups, explaining their relative lower archaic alleles, when compared with East-Eurasians.[2] This hypothetical population was proposed to explain the lower archaic admixture among West-Eurasians, although alternatives without the need of such Basal lineage exist as well.[1]
Basal-Eurasians represent a Eurasian lineage which split from East-Eurasians before the Mesolithic European Hunter-Gatherers diverged from them, and therefore form a more basal lineage of "Middle Eastern hunter-gatherers".[3] The areas of the Near East where the hypothetical Basal Eurasians resided may have been areas where contact with Neanderthals, who were known to have lived in Eurasia, were not made or were very rare. Consequently, Basal Eurasians likely did not become admixed with Neanderthals.[4][5][6][7] prior to their divergence from East-Eurasians.[5] The admixture of the main lineage of all other non-Africans with Neanderthals likely occurred 50,000-60,000 years ago, before early European hunter-gatherers (pre-Neolithic), diverged from East Asians and Oceanians).[1]
Ancestry associated with Basal Eurasians seems also to have spread together with contemporary West-Eurasian ancestry into Northern Africa and South Asia during the Paleolithic or the Holocene.[4]
The scenario of a non-Neanderthal-admixed modern human population, which is basal to other Eurasians, and resided within Africa or in close proximity, is plausible.[1] In particular, North Africa and Western Asia are strong candidates as a location for the emergence of Basal-Eurasians as it shares notable connection with Eurasian associated ancestry.[8]
An estimation for Holocene-era Near Easterners (e.g., Mesolithic Caucasian Hunter Gatherers, Mesolithic Iranians, Neolithic Iranians, Natufians) suggests that they formed from up to 50% Basal Eurasian ancestry, with the remainder being closer to Ancient North Eurasians.[8]
The Ancient North African Taforalt individuals were found to have harbored ~65% West-Eurasian-like ancestry and considered likely direct descendants of such "Basal Eurasian" population. However they were shown to be genetically closer Holocene-era Iranians and Levantine populations, which can already harbored increased archaic (Neanderthal) admixture.[8]
Early European Farmers (EEFs), who had some Western European Hunter-Gatherer-related ancestry and originated in the Near East, also derive approximately 44% of their ancestry from this hypothetical Basal Eurasian lineage.[2]
The existence of the Basal-Eurasians and own population lineage is questioned by more recent genetic and archaeogenetic data, supporting a repeated population hub expansion, in which West-Eurasians expanded after East-Eurasians, and received less archaic admixture, with the least archaic admixture among Middle Eastern populations. The most basal lineage could be associated with the "Zlatý Kůň" sample, which may form a deep sister clade to early West-Eurasian, however had a distinct position in a worldwide genomic comparison, and did not contribute to any modern humans. The 2022 study concluded that the ancestors of all non-African populations lived somewhere in southwestern Eurasia, persisted as a single population for at least 15 thousand years after the putative "OoA bottleneck", than split between West-and East-Eurasian populations, marking the beginning of a broader expansion) and later diffused from this “population Hub” ultimately colonizing all of Eurasia and further, with varying degrees of archaic admixture.[9]
We used an approach that integrates genetic with archaeological evidence to model the peopling of Eurasia by Homo sapiens after the Out of Africa (OoA); we infer the presence of an OoA population Hub from which multiple waves of expansion (chronologically, genetically, and technologically distinct) emanated to populate the new continent. We explain the East/West Eurasian population split as a longer permanence of the latter in the OoA Hub, and provide an explanation for the mixed East–West ancestry reported for paleolithic Siberians and, to a minor extent, GoyetQ116-1 in Belgium. We propose a parsimonious placement of Oase1 as an individual related to Bacho Kiro who experienced additional Neanderthal introgression and confirm Zlatý Kůň genetically as the most basal OoA human lineage sequenced to date, also in comparison to Oceanians and putatively link it with non-Mousterian material cultures documented in Europe 48–43 ka.
— Vallini et al. 2022
Hypothetical Basal-Eurasian ancestry peaks among Eastern Arabs (Qataris) and Iranian populations, and is also found in significant amounts among Ancient Iberomarusian samples and modern Northern Africans, in accordance with the Arabian branch of West-Eurasian diversity, which expanded into Northern and Northeastern Africa between 30-15 thousand years ago.[3]
References
- ^ a b c d Lazaridis, I (2016). "Genomic insights into the origin of farming in the ancient Near East" (PDF). Nature. 536 (7617): 419–424. Bibcode:2016Natur.536..419L. doi:10.1038/nature19310. PMC 5003663. PMID 27459054.
- ^ a b c Lazaridis, Iosif (2014). "Ancient human genomes suggest three ancestral populations for present-day Europeans". Nature. 513 (7518): 409–413. arXiv:1312.6639. Bibcode:2014Natur.513..409L. doi:10.1038/nature13673. PMC 4170574. PMID 25230663.
- ^ a b Ferreira, Joana C.; Alshamali, Farida; Montinaro, Francesco; Cavadas, Bruno; Torroni, Antonio; Pereira, Luisa; Raveane, Alessandro; Fernandes, Veronica (2021-09-01). "Projecting Ancient Ancestry in Modern-Day Arabians and Iranians: A Key Role of the Past Exposed Arabo-Persian Gulf on Human Migrations". Genome Biology and Evolution. 13 (9): evab194. doi:10.1093/gbe/evab194. ISSN 1759-6653. PMC 8435661. PMID 34480555.
- ^ a b Bergström, Anders; et al. "Origins of modern human ancestry" (PDF). Nature.
- ^ a b Lazaridis, Iosif (2018). "The evolutionary history of human populations in Europe". Current Opinion in Genetics & Development. 53: 21–27. arXiv:1805.01579. doi:10.1016/j.gde.2018.06.007. PMID 29960127.
- ^ Lazaridis, Iosif (2016). "Genomic insights into the origin of farming in the ancient Near East". Nature. 536 (7617): 419–424. Bibcode:2016Natur.536..419L. doi:10.1038/nature19310. PMC 5003663. PMID 27459054.
- ^ Fu, Qiaomei (2016). "The genetic history of Ice Age Europe". Nature. 534 (7606): 200–205. Bibcode:2016Natur.534..200F. doi:10.1038/nature17993. hdl:10211.3/198594. PMC 4943878. PMID 27135931.
- ^ a b c Van de Loosdrecht, Marieke. "Supplementary Materials for Pleistocene North African genomes link Near Eastern and sub-Saharan African human populations". Science. Science.
- ^ Vallini, Leonardo; Marciani, Giulia; Aneli, Serena; Bortolini, Eugenio; Benazzi, Stefano; Pievani, Telmo; Pagani, Luca (7 April 2022). "Genetics and Material Culture Support Repeated Expansions into Paleolithic Eurasia from a Population Hub Out of Africa". academic.oup.com. doi:10.1093/gbe/evac045. PMC 9021735. PMID 35445261. Retrieved 2022-08-27.