| 1. |
- Raghavan, Maanasa, et al.
(författare)
-
Genomic evidence for the Pleistocene and recent population history of Native Americans
- 2015
-
Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 349:6250
-
Tidskriftsartikel (refereegranskat)abstract
- Howand when the Americas were populated remains contentious. Using ancient and modern genome-wide data, we found that the ancestors of all present-day Native Americans, including Athabascans and Amerindians, entered the Americas as a single migration wave from Siberia no earlier than 23 thousand years ago (ka) and after no more than an 8000-year isolation period in Beringia. After their arrival to the Americas, ancestral Native Americans diversified into two basal genetic branches around 13 ka, one that is now dispersed across North and South America and the other restricted to North America. Subsequent gene flow resulted in some Native Americans sharing ancestry with present-day East Asians (including Siberians) and, more distantly, Australo-Melanesians. Putative "Paleoamerican" relict populations, including the historical Mexican Pericues and South American Fuego-Patagonians, are not directly related to modern Australo-Melanesians as suggested by the Paleoamerican Model.
|
|
| 2. |
- Perri, Angela R., et al.
(författare)
-
Dog domestication and the dual dispersal of people and dogs into the Americas
- 2021
-
Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 118:6
-
Tidskriftsartikel (refereegranskat)abstract
- Advances in the isolation and sequencing of ancient DNA have begun to reveal the population histories of both people and dogs. Over the last 10,000 y, the genetic signatures of ancient dog remains have been linked with known human dispersals in regions such as the Arctic and the remote Pacific. It is suspected, however, that this relationship has a much deeper antiquity, and that the tandem movement of people and dogs may have begun soon after the domestication of the dog from a gray wolf ancestor in the late Pleistocene. Here, by comparing population genetic results of humans and dogs from Siberia, Beringia, and North America, we show that there is a close correlation in the movement and divergences of their respective lineages. This evidence places constraints on when and where dog domestication took place. Most significantly, it suggests that dogs were domesticated in Siberia by similar to 23,000 y ago, possibly while both people and wolves were isolated during the harsh climate of the Last Glacial Maximum. Dogs then accompanied the first people into the Americas and traveled with them as humans rapidly dispersed into the continent beginning similar to 15,000 y ago.
|
|
| 3. |
- Schroeder, Kari B., et al.
(författare)
-
Haplotypic background of a private allele at high frequency in the Americas
- 2009
-
Ingår i: Molecular biology and evolution. - : Oxford University Press (OUP). - 0737-4038 .- 1537-1719. ; 26:5, s. 995-1016
-
Forskningsöversikt (refereegranskat)abstract
- Recently, the observation of a high-frequency private allele,the 9-repeat allele at microsatellite D9S1120, in all sampledNative American and Western Beringian populations has been interpretedas evidence that all modern Native Americans descend primarilyfrom a single founding population. However, this inference assumedthat all copies of the 9-repeat allele were identical by descentand that the geographic distribution of this allele had notbeen influenced by natural selection. To investigate whetherthese assumptions are satisfied, we genotyped 34 single nucleotidepolymorphisms across 500 kilobases (kb) around D9S1120 in 21Native American and Western Beringian populations and 54 otherworldwide populations. All chromosomes with the 9-repeat alleleshare the same haplotypic background in the vicinity of D9S1120,suggesting that all sampled copies of the 9-repeat allele areidentical by descent. Ninety-one percent of these chromosomesshare the same 76.26 kb haplotype, which we call the "AmericanModal Haplotype" (AMH). Three observations lead us to concludethat the high frequency and widespread distribution of the 9-repeatallele are unlikely to be the result of positive selection:1) aside from its association with the 9-repeat allele, theAMH does not have a high frequency in the Americas, 2) the AMHis not unusually long for its frequency compared with otherhaplotypes in the Americas, and 3) in Latin American mestizopopulations, the proportion of Native American ancestry at D9S1120is not unusual compared with that observed at other genomewidemicrosatellites. Using a new method for estimating the timeto the most recent common ancestor (MRCA) of all sampled copiesof an allele on the basis of an estimate of the length of thegenealogy descended from the MRCA, we calculate the mean timeto the MRCA of the 9-repeat allele to be between 7,325 and 39,900years, depending on the demographic model used. The resultssupport the hypothesis that all modern Native Americans andWestern Beringians trace a large portion of their ancestry toa single founding population that may have been isolated fromother Asian populations prior to expanding into the Americas.
|
|
