Diversity and age of the four major mtDNA haplogroups, and their implications for the peopling of the new world
Diversity and age of the four major mtDNA haplogroups, and their implications for the peopling of the new world
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DOI：
10.1086/301629
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发表时间：
1997-12-01
影响因子：
9.8
通讯作者：
Salzano, FM
中科院分区：
文献类型：
--
作者：
Bonatto, SL;Salzano, FM
尽管进行了大量的调查，但关于美洲原住民起源的两个主要问题仍然是激烈辩论的主题，即移民到美洲的数量和时间。使用720个可用的美洲印第安人mtDNA控制区序列，我们重新分析了四个主要mtDNA单倍型群（A-D）中发现的核苷酸多样性，这些单倍型群被认为存在于新大陆的殖民化中。我们首先验证了单倍群内序列多样性是否可以作为单倍群年龄的衡量标准。共享多态性的模式，错配分布，系统发育树，Tajima的D值，和计算机模拟都表明，这四个单倍型群经历了一个瓶颈，然后是一个大的人口扩张。这四个单倍型群的多样性非常相似，为它们的单一起源提供了有力的支持。他们认为，美洲原住民祖先群体分化的开始时间与距今3万至4万年（ybp）相似，95%置信区间的下限与25，000 ybp相似。这些值与我们在其他地方提出的新大陆定居模型非常一致，将最初在单倍群A中发现的结果扩展到美洲发现的其他三个主要mtDNA序列组。这些结果将美洲的人口清楚地置于克洛维斯之前的早期时间框架内。
Despite considerable investigation, two main questions on the origin of Native Americans remain the topic of intense debate-namely, the number and time of the migration(s) into the Americas. Using the 720 available Amerindian mtDNA control-region sequences, we reanalyzed the nucleotide diversity found within each of the four major mtDNA haplogroups (A-D) thought to have been present in the colonization of the New World. We first verified whether the within-haplogroup sequence diversity could be used as a measure of the haplogroup's age. The pattern of shared polymorphism, the mismatch distribution, the phylogenetic trees, the value of Tajima's D, and the computer simulations all suggested that the four haplogroups underwent a bottleneck followed by a large population expansion. The four haplogroup diversities were very similar to each other, offering a strong support for their single origin. They suggested that the beginning of the Native Americans' ancestral-population differentiation occurred similar to 30,000-40,000 years before the present (ybp), with a 95%-cofidence-interval lower bound of similar to 25,000 ybp. These values are in good agreement with the New World-settlement model that we have presented elsewhere, extending the results initially found for haplogroup A to the three other major groups of mtDNA sequences found in the Americas. These results put the peopling of the Americas clearly in an early, pre-Clovis time frame.