Basal Yammacin Afirka

Basal Yammacin Afirka shine hasashe na zuriya   wanda ba ya wanzu. 

 Tarihi 
Yin amfani da Yammacin Afirka (misali, Esan na Najeriya, Mende na Saliyo, Gambian yamma ), bambance-bambancen sa na farko na zamani ko na zamani mutane, ƙidaya a kusa da 25,000 ko tsakanin 23,000 da 27,000, daga ko dai na karshe na kowa kakannin San mutane da duk sauran zamani mutane, ko kuma mutane sun faru a tsakanin mutane da Neander. 1,020,000 BP da 360,000 BP.  Basal Yammacin Afirka ba su rabu ba kafin Neanderthals ya rabu da mutanen zamani.  Tun kafin 300,000 BP zuwa 200,000 BP, lokacin da kakannin San na zamani suka rabu da sauran mutane na zamani, ƙungiyar da za ta rabu da farko daga mutanen zamani na iya zama Basal West Africa. 

Tsakanin 124,000 BP da 0 BP, 2% - 19% na kwayoyin halitta na iya shiga cikin kakannin mutanen yammacin Afirka na zamani a sakamakon hadewa da wannan yawan ɗan adam . Durvasula, Arun; Sankararaman, Sriram (2020). "Recovering signals of ghost archaic introgression in African populations". Science Advances. 6 (7): eaax5097. Bibcode:2020SciA....6.5097D. doi:10.1126/sciadv.aax5097. ISSN 2375-2548. OCLC 8538353312. PMC 7015685. PMID 32095519. S2CID 211472946. Mutanen yammacin Afirka na zamani (misali, Yarbawan Ibadan, Najeriya, Mende na Saliyo) na iya samun zuriya daga wannan zuriyar sakamakon zuriyarsu daga Basal West Africa.   Hakanan wannan binciken ya nuna cewa aƙalla ɓangare na wannan admixture na archaic shima yana cikin Eurasians / waɗanda ba 'yan Afirka ba, da kuma cewa taron admixture ko abubuwan da suka faru ya fito daga 0 zuwa 124 ka BP, wanda ya haɗa da lokacin kafin ƙaura daga Afirka da kuma kafin rarrabuwar Afirka / Eurasian (don haka ya shafi wani ɓangare na kakannin kakannin Afirka da Euras / Afirka).  "Non-African populations (Han Chinese in Beijing and Utah residents with northern and western European ancestry) also show analogous patterns in the CSFS, suggesting that a component of archaic ancestry was shared before the split of African and non-African populations...One interpretation of the recent time of introgression that we document is that archaic forms persisted in Africa until fairly recently. Alternately, the archaic population could have introgressed earlier into a modern human population, which then subsequently interbred with the ancestors of the populations that we have analyzed here. The models that we have explored here are not mutually exclusive, and it is plausible that the history of African populations includes genetic contributions from multiple divergent populations, as evidenced by the large effective population size associated with the introgressing archaic population...Given the uncertainty in our estimates of the time of introgression, we wondered whether jointly analyzing the CSFS from both the CEU (Utah residents with Northern and Western European ancestry) and YRI genomes could provide additional resolution. Under model C, we simulated introgression before and after the split between African and non-African populations and observed qualitative differences between the two models in the high-frequency–derived allele bins of the CSFS in African and non-African populations (fig. S40). Using ABC to jointly fit the high-frequency–derived allele bins of the CSFS in CEU and YRI (defined as greater than 50% frequency), we find that the lower limit on the 95% credible interval of the introgression time is older than the simulated split between CEU and YRI (2800 versus 2155 generations B.P.), indicating that at least part of the archaic lineages seen in the YRI are also shared with the CEU..."   Supplementary Materials for Recovering signals of ghost archaic introgression in African populations", section "S8.2" "We simulated data using the same priors in Section S5.2, but computed the spectrum for both YRI [West African Yoruba] and CEU [a population of European origin] . We found that the best fitting parameters were an archaic split time of 27,000 generations ago (95% HPD: 26,000-28,000), admixture fraction of 0.09 (95% HPD: 0.04-0.17), admixture time of 3,000 generations ago (95% HPD: 2,800-3,400), and an effective population size of 19,700 individuals (95% HPD: 19,300-20,200). We find that the lower bound of the admixture time is further back than the simulated split between CEU and YRI (2155 generations ago), providing some evidence in favor of a pre-Out-of-Africa event. This model suggests that many populations outside of Africa should also contain haplotypes from this introgression event, though detection is difficult because many methods use unadmixed outgroups to detect introgressed haplotypes [Browning et al., 2018, Skov et al., 2018, Durvasula and Sankararaman, 2019] (5, 53, 22). It is also possible that some of these haplotypes were lost during the Out-of-Africa bottleneck."  Chen et al. (2020) ya gano cewa mutanen Afirka suna da zuriyar Neanderthal fiye da yadda ake tsammani a baya. An tantance samfuran Afirka 2,504 daga ko'ina cikin Afirka kuma an gwada su akan zuriyar Neanderthal. Duk samfuran Afirka sun nuna shaida ga ƙananan zuriyar Neanderthal, amma koyaushe a ƙananan matakan fiye da yadda aka gani a cikin Eurasia. 

 Mafarauta na Yammacin Afirka, Khoisan, da Taforalts 
Yayin da mafi ƙarancin ƙirar ƙira (ba tare da Basal Yammacin Afirka ba) don zuriyar Shum Laka masu neman abinci ya ƙunshi tsoffin Taforalts daga al'adun Iberomaurusian da mutanen Yammacin Afirka na zamani, a tsakanin sauran nau'ikan ƙirar ƙira, ɗayan ya tsara zuriyar Shum Laka masu kiwon Shum Laka a matsayin 65% Basal West Africa da 35% na yammacin Afirka ta Tsakiya .  Duk da haka, akwai rashin zuriyar Basal na yammacin Afirka a cikin mafarauta na zamani na Kamaru. 

Mutanen kudancin Afirka (misali, Khoisan ), waɗanda suka fi kusanci ga zuriyar Afirka ta Gabas, sun fi nisa a zuriyar mutanen yammacin Afirka.  Montinaro, Francesco; Capelli, Cristian (2018). "The evolutionary history of Southern Africa". Current Opinion in Genetics & Development. 53: 160. doi:10.1016/j.gde.2018.11.003. PMID 30522870. S2CID 54483869. Yayin da ake gwagwarmaya da tsarin da ke tallafawa 'yan Afirka ta Kudu a matsayin rukuni na farko don rabuwa da mutane na zamani, Basal West Africans, a matsayin jinsin hasashe, sun goyi bayan nau'i biyu na daidaitattun daidaito - ƙungiyar basal na farko daga Gabashin Afirka, wanda ya kasance wani ɓangare na tsohuwar tsarin kwayoyin halitta a Afirka, wani ɓangare ne na kakannin zamani na zamani na yammacin Afirka na zamani (misali, Yoruba, Mende) ko Yarbawa na zamani (misali, Yarbanci, Mende) ko Yarbawa na zamani, Mened Admix na Yammacin Afirka. Sakamakon ƙungiyoyin basal masu ƙaura daga sassa daban-daban na Afirka (watau Kudu maso Gabashin Afirka, Yammacin Afirka ).  

Baya ga samun kamanceceniya da ragowar zuriyar Afirka ta Kudu da ke kudu da hamadar Sahara (misali, zuriyar Basal ta Yammacin Afirka da aka raba tsakanin mutanen Yarbawa da Mende), Skoglund, Pontus; et al. (2017). "Reconstructing Prehistoric African Population Structure". Cell. 171 (1): 59–71.e21. doi:10.1016/j.cell.2017.08.049. ISSN 0092-8674. OCLC 7144495602. PMC 5679310. PMID 28938123. S2CID 1257429.  DNA na Afirka ta Kudu a cikin Taforalts na al'adun Iberomaurusian na iya zama mafi wakilcin mutanen yammacin Afirka na zamani (misali, Yarbawa). 

 Zuriya 
Yarabawa da Mende sun fito ne daga Basal Afirka ta Yamma da kuma wasu kakanni na gabacin Afirka ta Gabas da waɗanda ba Afirka ba, wanda ke nuni da ƙaura daga Gabashin Afirka. Yarabawa suna da ƙarancin zuriya daga Basal Afirka ta Yamma fiye da mutanen Mende, waɗanda ke da yawan zuriya. Musamman ma, Yarbawa suna da kashi 9% na asalin Basal na Afirka ta Yamma kuma mutanen Mende suna da kashi 13% na Basal na yammacin Afirka.

 Magana