Archaic human genomics
Archaic human genomics
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DOI：
10.1002/ajpa.22159
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发表时间：
2012-01-01
影响因子：
2.8
通讯作者：
Disotell, Todd R.
中科院分区：
文献类型：
--
作者：
Disotell, Todd R.
在20世纪的大部分时间里，人类进化史的主流观点来自化石记录。直立人起源于非洲，起源于该属的早期成员，然后在整个旧大陆传播到大洋洲。从H.直立人通过各种中间古代物种进入现代人类，在每个地区居住的H。直立人被称为人类进化的多区域模型（MRE）。一个对比模型假设解剖学上现代的H.智人与一些人口后来迁移出非洲，并取代当地的古代人口在世界各地的完全取代成为众所周知的最近非洲起源（RAO）模式。几十年来，这两种模型的支持者对化石记录的不同解释支持了他们的观点。在20世纪80年代，分子遗传学技术开始提供现代人类变异的证据，不仅可以测试现代人类起源的不同模型，还可以探索人口统计学历史和基因组不同区域甚至特定性状所经历的选择类型。大多数研究人员将这些数据解释为强烈支持RAO模型，特别是线粒体DNA（mtDNA）的分析。从现代的变异模式向后推断，并使用各种校准点和替代率，出现了一种共识，即现代人类是从大约20万年前的非洲人口进化而来的。很久以后，大约5万年前，这一人口的一个子集迁移出非洲，取代了欧洲和西亚的尼安德特人以及东亚和大洋洲的古人类。来自二十多个尼安德特人和早期现代人的mtDNA序列加强了这一共识。然而，在2010年，尼安德特人和西伯利亚迄今未知的人类（称为丹尼索瓦人）的完整基因组草图证明了这些古老的人类物种和现代欧亚人之间的基因流动，而不是撒哈拉以南的非洲人。虽然基因流动的水平可能非常有限，但这一意外发现与RAO模型或MRE模型都不吻合。对现代人类多样性进行更彻底的采样，发现更多的化石，并对更多的人类化石进行测序，这对我们的起源和历史是必要的。《美国物理人类学杂志》，2012年。(C)2012 Wiley Periodicals，Inc.
For much of the 20th century, the predominant view of human evolutionary history was derived from the fossil record. Homo erectus was seen arising in Africa from an earlier member of the genus and then spreading throughout the Old World and into the Oceania. A regional continuity model of anagenetic change from H. erectus via various intermediate archaic species into the modern humans in each of the regions inhabited by H. erectus was labeled the multiregional model of human evolution (MRE). A contrasting model positing a single origin, in Africa, of anatomically modern H. sapiens with some populations later migrating out of Africa and replacing the local archaic populations throughout the world with complete replacement became known as the recent African origin (RAO) model. Proponents of both models used different interpretations of the fossil record to bolster their views for decades. In the 1980s, molecular genetic techniques began providing evidence from modern human variation that allowed not only the different models of modern human origins to be tested but also the exploration demographic history and the types of selection that different regions of the genome and even specific traits had undergone. The majority of researchers interpreted these data as strongly supporting the RAO model, especially analyses of mitochondrial DNA (mtDNA). Extrapolating backward from modern patterns of variation and using various calibration points and substitution rates, a consensus arose that saw modern humans evolving from an African population around 200,000 years ago. Much later, around 50,000 years ago, a subset of this population migrated out of Africa replacing Neanderthals in Europe and western Asia as well as archaics in eastern Asia and Oceania. mtDNA sequences from more than two-dozen Neanderthals and early modern humans re-enforced this consensus. In 2010, however, the complete draft genomes of Neanderthals and of heretofore unknown hominins from Siberia, called Denisovans, demonstrated gene flow between these archaic human species and modern Eurasians but not sub-Saharan Africans. Although the levels of gene flow may be very limited, this unexpected finding does not fit well with either the RAO model or MRE model. More thorough sampling of modern human diversity, additional fossil discoveries, and the sequencing of additional hominin fossils are necessary to throw light onto our origins and our history. Am J Phys Anthropol, 2012. (C) 2012 Wiley Periodicals, Inc.