|
|
本帖最后由 baiyueren 于 2018-1-24 17:20 编辑
原文找到了是这一篇：Genetic evidence for two founding populations of the Americas
Genetic studies have consistently indicated a single common origin of Native American groups from Central and South America1,2,3,4. However, some morphological studies have suggested a more complex picture, whereby the northeast Asian affinities of present-day Native Americans contrast with a distinctive morphology seen in some of the earliest American skeletons, which share traits with present-day Australasians (indigenous groups in Australia, Melanesia, and island Southeast Asia)5,6,7,8. Here we analyse genome-wide data to show that some Amazonian Native Americans descend partly from a Native American founding population that carried ancestry more closely related to indigenous Australians, New Guineans and Andaman Islanders than to any present-day Eurasians or Native Americans. This signature is not present to the same extent, or at all, in present-day Northern and Central Americans or in a ∼12,600-year-old Clovis-associated genome, suggesting a more diverse set of founding populations of the Americas than previously accepted.
显示亚马逊几个部落Paiter-Surui、Karitiana和Xavante有与澳洲、巴布亚、安达曼人接近的常染成分（Onge人发生频率最高）。既然与安达曼人也接近，那就不可能是现代成分，而只能是古老成分遗存。
Figure 2.
A model of population history that can explain the excess affinity to Oceanians observed in
Amazonian populations. We fit an admixture graph model illustrated in a) where a
population related to the Andamanese Onge contributed a fraction α of the ancestry of
‘Population Y’, which later contributed a fraction γ to the ancestry of Amazonian groups
today (the remainder of which is related to Mesoamerican Mixe). B) two-dimensional grid
of combinations of the admixture proportions α and γ which are compatible with the data in
the sense of how many predicted f4-statistics deviate by Z ≥3.0 from empirical values. The
cross represents the parameter combination fitted heuristically using ADMIXTUREGRAPH. |
|
发表于 2018-1-24 15:03
发表于 2018-1-24 15:34
发表于 2018-1-27 10:20
