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Amerindians' Migrations, Ethnogenesis, and DNA
I thought it’d be fruitful to understand more about the peoples who inhabited the Americas before other groups and ended up mixing with Europeans from North to South of the continent. Due to the Amerindian ancestry of a big part of the population in the New World, including some predominantly white persons, I think it’s a pertinent subject even for a European Cultural CommunityTM.
According to the BBC article https://www.bbc.com/news/science-environment-18770963
The paper on which it was based ( Reconstructing Native American population history, https://www.nature.com/articles/nature11258) further explains:The biggest survey of Native American DNA has concluded that the New World was settled in three major waves.
But the majority of today's indigenous Americans descend from a single group of migrants that crossed from Asia to Alaska 15,000 years ago or more.
And it doesn’t end there:The pattern of dispersals within the Americas is also poorly understood. To address these questions at a higher resolution than was previously possible, we assembled data from 52 Native American and 17 Siberian groups genotyped at 364,470 single nucleotide polymorphisms. Here we show that Native Americans descend from at least three streams of Asian gene flow. Most descend entirely from a single ancestral population that we call ‘First American’. However, speakers of Eskimo–Aleut languages from the Arctic inherit almost half their ancestry from a second stream of Asian gene flow, and the Na-Dene-speaking Chipewyan from Canada inherit roughly one-tenth of their ancestry from a third stream. We show that the initial peopling followed a southward expansion facilitated by the coast, with sequential population splits and little gene flow after divergence, especially in South America. A major exception is in Chibchan speakers on both sides of the Panama isthmus, who have ancestry from both North and South America.
[…] An early split separates Asians from Native Americans and extreme northeastern Siberians (Chukchi, Naukan, Koryak), which is consistent with studies that have identified pan-American variants shared with some northeastern Siberians6,7,10,18. Eskimo–Aleut speakers and far-northeastern Siberians form a cluster that is separated from other Native American populations by a long internal branch.
It might be more complicated, though. Genetic evidence for two founding populations of the Americas (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4982469/) suggests some Amazonian groups are more related to present-day Australasians than to anyone else.[…] This supports the hypothesis of three deep lineages in Native Americans: the Asian lineage leading to First Americans is the most deeply diverged, whereas the Asian lineages leading to Eskimo–Aleut speakers and the Na-Dene-speaking Chipewyan are more closely related and descend from a putative Siberian ancestral population more closely related to Han (Fig. 2). We also arrive at the finding that Eskimo– Aleut populations and the Chipewyan derive large proportions of their genomes from First American ancestors: an estimated 57% for Eskimo–Aleut speakers, and 90% in the Chipewyan, probably reflecting major admixture events of the two later streams of Asian migration with the First Americans that they encountered after they arrived (Supplementary Notes). The high proportion of First American ancestry explains why Eskimo–Aleut and Chipewyan populations cluster with First Americans in trees like that in Fig. 1c despite having some of their ancestry from later streams of Asian migration, and explains the observation of some genetic variants that are shared by all Native Americans but are absent elsewhere6,7,10,18. We also infer back-migration of populations related to the Eskimo–Aleut from America into far-northeastern Siberia (we obtain an excellent fit to the data when we model the Naukan and coastal Chukchi as mixtures of groups related to the Greenland Inuit and Asians (Fig. 2 and Supplementary Notes)). This explains previous findings of panAmerican alleles also in far-northeastern Siberia6,7,10,18.
[…] Figure 3 presents an AG we built for 16 selected Native American populations and two outgroups, which is a good fit to the data in that the largest jZj-score for a difference between the observed and predicted f-statistics is 3.2 from among the 11,781 statistics we tested.
Other links between Polynesians and South America had already been proposed, such as the introduction of the chicken and of the bottle gourd to the continent by Polynesians via Chile and of the South American sweet potato to the South Pacific, though the first two have already been somewhat discredited to have a connection to Polynesians https://www.nationalgeographic.com/h...merica-science.All Native American groups studied to date can trace all or much of their ancestry to a single ancestral population that likely migrated across the Bering land bridge from Asia more than 15,000 years ago2, with some Northern American and Arctic groups also tracing other parts of their ancestry to more recent waves of migration2,9,10. Ancient genomic evidence has shown that this so-called ‘First American’ ancestry is present in an individual associated with Clovis technology from North America dating to ~12,600 years ago3, and mitochondrial DNA has suggested that it was also present by 13,000-14,500 years ago11,12. In contrast, some morphological analyses of early skeletons in the Americas have suggested that characteristics of some Pleistocene and early Holocene skeletons fall outside the variation of present-day Native Americans, and instead within the variation of present-day indigenous Australians, Melanesians, and so-called ‘Negrito’ groups from Southeast Asia (and some sub-Saharan African groups)
Finally, we generated new data from 9 populations from present-day Brazil using the Affymetrix Human Origins array, including previously untested individuals from the Amazonian Suruí and Karitiana for which DNA was extracted from blood. These new samples replicate the signal, and furthermore show that the signal is also strong in the Xavante (1.3 < Z < 3.25), a population of the Brazilian Central Plateau that speaks a language of the Ge group that is different from the Tupi language group to which the languages that the Karitiana and Suruí speak both belong. We do not detect any excess affinity to Australasians in the ~12,600 year old Clovis-associated Anzick individual from Western Montana (Z = −0.6) (SI 3).
[…] We have provided compelling evidence that a Population Y that has ancestry from a lineage more closely related to present-day Australasians than to present-day East Asians and Siberians, contributed a small fraction of the DNA of Native Americans from Amazonia and the Central Brazilian Plateau. This discovery is striking in light of interpretations of the morphology of some early Native American skeletons, which some authors have suggested have affinities to Australasian groups. The largest number of skeletons that have been described as having this craniofacial morphology and that date to younger than ten thousand years have been found in Brazil6, the home of the Suruí, Karitiana and Xavante who in genetic data show the strongest affinity to Australasians.
A more complex model than the three-waves theory, with contribution from Pacific Islanders, was also backed by other study: The Origin of Amerindians and the Peopling of the Americas According to HLA Genes: Admixture with Asian and Pacific People https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2874220/.
On the other hand, Native American gene flow into Polynesia predating Easter Island settlement (https://www.nature.com/articles/s415...m=article_link) found evidence for the contact to had been with Native Americans from Northern South America.The classical three-waves theory of American peopling through Beringia was based on a mixed anthropological and linguistic methodology. The use of mtDNA, Y chromosome and other DNA markers offers different results according to the different markers and methodologies chosen by different authors. At present, the peopling of Americas remains uncertain, regarding: time of population, number of peopling waves and place of peopling entrance among other related issues. In the present review, we have gathered most available HLA data already obtained about First Native American populations, which raise some doubts about the classical three waves of American peopling hypothesis. In summary, our conclusions are: 1) North West Canadian Athabaskans have had gene flow with: a) close neighboring populations, b) Amerindians, c) Pacific Islanders including East Australians and d) Siberians; 2) Beringia was probably not the only entrance of people to America: Pacific Ocean boat trips may have contributed to the HLA genetic American profile (or the opposite could also be true); 3) Amerindians entrance to America may have been different to that of Athabaskans and Eskimos and Amerindians may have been in their lands long before Athabaskans and Eskimos because they present and altogether different set of HLA-DRB1 allele frequencies; 4) Amerindians show very few “particular alleles”, almost all are shared with other Amerindians, Athabaskans and Pacific Islanders, including East Australians and Siberians; 5) Our results do not support the three waves model of American peopling, but another model where the people entrance is not only Beringia, but also Pacific Coast. Reverse migration (America to Asia) is not discarded and different movements of people in either direction in different times are supported by the Athabaskan population admixture with Asian-Pacific population and with Amerindians, 6) HLA haplotype variability is more common than allele veriability in Amerindians. Finally, it is shown that gene genealogy analises should be completed with allele frequency analyses in population relatednes and migrations studies.
Genetic flow between the South American Pacific Coast and the Amazon was proposed by Deep genetic affinity between coastal Pacific and Amazonian natives evidenced by Australasian ancestry https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8040822/Consistent with our ADMIXTURE analysis, which showed a central Native American component in Pacific islanders, in this analysis the Native American ancestries of the Pacific islanders all fall within, or beside, the Zenu people—an indigenous Colombian population. The localization of the Native American component to Colombia–Ecuador is shown clearly by our new, lower-noise, ancestry-specific MDS analysis, as well as by PCA, and is consistent with the less-sensitive traditional Procrustes analysis and outgroup-f3 statistic (Supplementary Figs. 16–22). The only exceptions are the Rapanui individuals with high European ancestry. As expected, their Native American component, which probably came together with their European component through immigration of admixed Chilean individuals to Rapa Nui, is located squarely within the Pehuenche and Mapuche native populations of central Chile (Fig. 4b and Supplementary Figs. 14, 16, 18–22). The Native American ancestry component in Rapanui individuals with no European ancestry, by contrast, clusters with the Colombian Zenu people, just as with the other eastern islands.
Apart from the Chilean annexation of Rapa Nui in AD 1888 and sporadic interactions with ships’ crews, the only recorded events potentially connecting Pacific islanders with Native American ancestry are the Peruvian slave raids of AD 1862–1863. During this year, thousands of Pacific islanders were kidnapped and taken to Peru as forced labourers, including 1,407 Rapanui individuals. Following an international outcry, a few repatriation voyages were organized, but smallpox outbreaks onboard meant that only a handful of passengers made it back to Polynesia alive. Only two of the islands in our data set received any recorded returnees: Rapa Nui (15 repatriated) and Rapa Iti (9 captive individuals from other islands resettled). With very few individuals, all self-identifying as islanders, returning to Polynesia, and with their captivity in Peru lasting only a few months, it is unlikely that this episode resulted in any introgression of Native American ancestry into Polynesia. However, such explanations have been advanced. In any case, the Native American component that we observe in the easternmost islanders, including on distant islands untouched by returnee voyages, derives from an indigenous American population lying to the north of both of our Peruvian Native American reference individuals, namely the southern Peruvian Aymara and the northern Peruvian Magdalena (Fig. 4b and Supplementary Figs. 16, 18).
Our localization of the Native American ancestry found in Polynesia is consistent with several linguistic, historical and geographical observations that support an origin in northern South America. Although superficial similarities between the monolithic statues of the Pacific islands (found only in the remote eastern Polynesian islands) and those of the pre-Columbian site of San Augustín, Colombia, have long been noted, stronger evidence has come from the Polynesian word for the sweet potato, ‘kumala’. This word has been linked to names for the food in northern South America, where it originated. The coastal languages that use these related names lie to the north of Peru—for example, ‘cumal’ is used by the Cañari people of Ecuador—whereas the Peruvian languages that use such names are Andean and located far from the coast. It is to the north of Peru that the Pacific coast changes from desert to forests suitable for boat construction, and it is from Pacific Ecuador and Colombia that Native American voyagers are believed to have embarked for trade with Mesoamerica in large ocean-going sailing rafts made of balsa wood during the period AD 600 to AD 1200. Wind and current simulations from the Pacific coast of the Americas have shown that drift voyages departing from Ecuador and Colombia are the most likely to reach Polynesia, and that they arrive with the highest probability in the South Marquesas islands, followed by the Tuamotu Archipelago. Both of these archipelagos lie at the heart of the region of islands where we have found a Colombian Native American component. The trade winds and the south equatorial current move east to west at these latitudes, funnelling boaters from northern South America to the archipelagos. (In Thor Heryerdahl’s famous drift voyage from Peru to Polynesia, his Kon-Tiki raft had to be towed 80 miles offshore from Peru, because the southern current along the Peruvian coast was so unfavourable; once in the trans-Pacific currents the Kon-Tiki raft landed in the Tuamotu Archipelago.) For the same reason, these archipelagos would be the most likely origin for Polynesian individuals discovering the Americas using their characteristic upwind exploration.
Do you have Amerindian ancestry? If yes, from which tribe? Which DNA tests are the best discerning Native populations?The controversial Australasian population genetic component (i.e., “Ypikuéra population” or “Y population” component) was identified exclusively in the present-day Amazonian populations, suggesting at least two different founding waves leading to the formation of the people of this region.
[…] However, data from ancient South American samples indicated a weak Y signal around 10,000 yBP. This evidence indicates that, rather than a second wave entering South America from southeast Asia, the Y ancestry might be traced back to common ancestors of Native Americans, who lived in northeast Asia. Furthermore, a new line of evidence indicates that the first American clades split in East Asia, not in Beringia, which makes the gene flow of the Y ancestry from the ancestral East Asian groups even more likely.
[…] Our results showed that the Australasian genetic signal, previously described as exclusive to Amazonian groups, was also identified in the Pacific coastal population, pointing to a more widespread signal distribution within South America, and possibly implicating an ancient contact between Pacific and Amazonian dwellers. In addition, a significant amount of interpopulation and intrapopulation variation of this genetic signal was detected.
[…] This provides strong evidence that a significant variability of this signal exists not only at an interpopulation level but also between individuals from the same populations. These results suggest that the intrapopulation variability of this signal is not rare (Fig. 2) and is observed in several groups (Apalai, Guaraní Nãndeva, Karitiana, Munduruku, Parakanã, and Xavánte). Most significant tests detected this excess signal in Tupí-speaking individuals, but the signal was also detected in individuals from every major linguistic group (Fig. 2 and Dataset S4) and, at the same time, presented a widespread geographic distribution within South America (Fig. 1). Conversely, a considerable number of samples were inferred to have a deficit of allele sharing with Australasians (Fig. 2 and Dataset S4D)
[…] Archeological and genetic data demonstrated that both routes, Pacific coastal and inland, were likely used by the first migrants. Our models point to an ancient genetic affinity between the Pacific coast and Amazonian populations that could be explained by the presence of Y ancestry in both geographic regions. In addition, this shared ancestry seems to precede the separation of the Pacific and Amazon branches, showing an entry through the west coast, followed by successive events of genetic drift in the Brazilian populations. This genetic evidence for the presence of Y ancestry on the South American Pacific coast indicates that this ancestry likely reached this region through the Pacific coastal route, and therefore could explain absence of this genetic component in the populations of North and Central America studied so far.
If I forgot to include anything or if you have any opinion about the subject, please share your thoughts.
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Originally Posted by Vjatych
How is this possible? The Russians fought fiercely with the Tlingit.....The Cree Amerindians (Algonquian family of languages) have 25% of Western European DNA. This is logical.
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