Neanderthal 起源新认识

[yolanda]

Letter

Nature advance online publication 30 September 2007 | doi:10.1038/nature06193; Received 15 March 2007; Accepted 23 August 2007; Published online 30 September 2007

Neanderthals in central Asia and Siberia

Johannes Krause1, Ludovic Orlando2, David Serre3, Bence Viola4, Kay Prüfer1, Michael P. Richards1, Jean-Jacques Hublin1, Catherine Hänni2, Anatoly P. Derevianko5 & Svante Pääbo1

1. Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, D-04103 Leipzig, Germany
2. Paléogénétique et Évolution Moléculaire, Institut de Génomique Fonctionnelle de Lyon, Université de Lyon, Institut Fédératif Biosciences Gerland Lyon Sud, Université Lyon 1, CNRS, INRA, École Normale Supérieure de Lyon, 46 Allée d'Italie, 69364 Lyon, Cedex 07, France
3. McGill University and Genome Quebec Innovation Center, Montreal, Quebec H3A 1A4, Canada
4. Department of Anthropology, Faculty of Life Sciences, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
5. Paleolithic Department, Institute of Archaeology and Ethnography, Russian Academy of Sciences, Siberian Branch. Lavrentieva Prospekt, 17 Novosibirsk, 630090 Russia

Correspondence to: Svante Pääbo1 Correspondence and requests for materials should be addressed to S.P. (Email: mailto:paabo@eva.mpg.de).
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Abstract

Morphological traits typical of Neanderthals began to appear in European hominids at least 400,000 years ago1 and about 150,000 years ago2 in western Asia. After their initial appearance, such traits increased in frequency and the extent to which they are expressed until they disappeared shortly after 30,000 years ago. However, because most fossil hominid remains are fragmentary, it can be difficult or impossible to determine unambiguously whether a fossil is of Neanderthal origin. This limits the ability to determine when and where Neanderthals lived. To determine how far to the east Neanderthals ranged, we determined mitochondrial DNA (mtDNA) sequences from hominid remains found in Uzbekistan and in the Altai region of southern Siberia. Here we show that the DNA sequences from these fossils fall within the European Neanderthal mtDNA variation. Thus, the geographic range of Neanderthals is likely to have extended at least 2,000 km further to the east than commonly assumed.

last paragraph:

When the relationship of the Teshik Tash and Okladnikov mtDNA sequences to other Neanderthal mtDNA sequences is estimated (Supplementary Fig. 3), the Teshik Tash mtDNA sequence seems to be more closely related to the mtDNA sequence from Scladina in western Europe than to the sequence from Okladnikov. Further Neanderthal mtDNA sequences from across their range and from different time horizons will obviously be necessary to permit insights into how Neanderthals colonized both western and central parts of the Old World. However, the fact that no deep mtDNA divergence is seen between the central Asian Neanderthals and European and Caucasian Neanderthals shows that they were not separated for a long time. This supports the view that central Asia was colonized relatively recently by Neanderthals26. In fact, it has been suggested that Neanderthals did not colonize most of the Russian plains before an exceptionally warm episode 125,000 years ago27, during which the Caspian Sea was drastically reduced in size. This may have facilitated the expansion of Neanderthals into central Asia and Southern Siberia26. Intriguingly, their presence in southern Siberia raises the possibility that they may have been present even farther to the east, in Mongolia and China. Further work will be necessary to address this possibility.

[yijun]

化石遗存物上找mtDNA，不了解这方面的工作，太容易受到污染了。。。mtDNA的特征性如何？

[yolanda]

mtDNA 母系遗传， 个体之间变化较大， 故适合用来溯种族群体的来源； 人类mtDNA 环形， 只编码37个基因， 大部分与能量运用有关； 至于污染问题， mtDNA 也许拷贝数较多， 而且与现代人类区别很大， 相对容易鉴别吧。

[yijun]

哦，我是联想到恐龙蛋那桩轶事。

不过还是好奇，骨骼化石化了，还能够取到核酸。。。什么时候找PAABO S. Molecular genetic investigations of ancient human remains[J ] . Cold Spring Harbor Symp. Quant . Biol . , 1986 51 : 441 - 446.这个看看。

搜了下：

目前,很多古DNA 的研究以mtDNA 为对象. mtDNA 比核DNA 拥有更多的拷贝数(每个细胞有100
～1000 线粒体拷贝) ,因此对mtDNA 的检测比核DNA 具有更高的灵敏度,这使mtDNA 更适用于古DNA
的研究. 此外,mtDNA 具有若干与核DNA 不同特征,使其在进化研究上具有特殊的意义: (1) mtDNA 很少
会发生重组[4 ] ; (2)mtDNA 存在着个体之间的差异,大多数变异主要集中于mtDNA 非编码区D2环的两个
高变片段HVSI、HVSII ; (3)mtDNA 存在着种族群体特征,所具有的母系单倍体遗传特点[5 ] ,能完整地记
录母系遗传史; (4) 有效群体大小(Effective Population Size) 仅为核DNA 的四分之一,突变率在核DNA 的
10 倍以上(常染色体及Y染色体1.9 ×10^-9～5.4 ×10^-9/位点/年,mtDNA 3.5 ×10^-8/位点/年) ,这两个特点,一方面使mtDNA 能在较短时间内积累比较多的突变;另一方面,在随机遗传漂变的作用下,产生了
高度的地区性群体差异,提高了mtDNA 在进化研究中的信息量和分辨率. 因此,古代mtDNA 的分析对人
类的起源和进化的研究有着重要的意义. 例如1987 年,Cann 等人在Nature 上发表的文章对来自世界各
地的147 例个体的mtDNA 进行高分辨率RFLP 分析,提出了人类起源与进化这一重大的生命科学命题
研究中著名的“非洲夏娃”学说[6 ] ;1997 年,对尼安德特人遗骸中线粒体DNA 的分析,则为这个学说提供
了有力的直接证据[7 ] ,因而被Science 评为1997 年“十大科学成就”之一.

[yolanda]

看来我总结概括能力照实有待提高！