Science2014-06-23 3:33 PM

具有混合特征的头颅阐释了人类的演化 Neandertal roots: Cranial and chronological evidence from Sima de los Huesos

论文摘要 

研究人员分析了从一个单一的挖掘遗址找到了迄今为止最大的一批古人类物种化石,它们可为尼安德特人的起源和演化提供线索。他们在这些化石中确认了源自尼安德特人的特征以及与更为原始的人类有关的特征。这一“镶嵌模式”支持了尼安德特人演化的一个理论——该理论提示,尼安德特人是在不同的时候分别发展出其用于定性的特征的,而不是一次性地发展出了所有的定性特征。有了这些新的来自西班牙的被称作Sima de los Huesos的洞穴遗址的数据能让科学家们更好地理解古人类在中更新世的演化;在该时期内,古人类的演化路程一直是有争议的。

大约在40万年至50万年之前——当时正处于更新世的中心,古人类与生活在非洲与东亚的其它种群分开,并最终在欧亚地区定居,它们正是在这里演化出了后来被定义为尼安德特人世系的特征。在此之后过了数十万年,现代人——他们是在非洲演化的——也在欧亚地区定居。他们与尼安德特人发生杂交,但却显示出了生殖不相容的迹象。正因为如此,现代人最终取代了尼安德特人。在如此短的时期内会在尼安德特人与现代人间有如此的差异程度令科学家们吃惊。为什么尼安德特人如此快地与其它早期人类分化?尼安德特人经历了什么变化模式?为了回答这些问题,他们需要对大约40万年前——这是尼安德特人世系的早期阶段——欧洲人群有一个准确的理解。然而,要获得这一理解一直是有挑战性的,因为欧洲的化石记录是孤立且分散的,它们是由全异的时间线组成的。然而,从Sima de los Huesos遗址得到的样本有所不同——它们代表了前所未有的来自某单一物种的古人类化石的积累,并包括有17个头颅,它们中有许多非常完整。它们中有些过去被研究过, Juan-Luis Arsuaga及其同事在此研究中再一次地对其中7个头颅进行了介绍。

在研究这些完整的样本时,研究人员观察到了一种模式:这些样本的脸和牙齿具有尼安德特人的特征,但其它地方则没有该特征。至关重要的是,许多源自尼安德特人的特征都与咀嚼有关。由Arsuaga等人所做的工作帮助解释了有关尼安德特人演化的假说,特别是累积模型假说,后者提出尼安德特人是在不同时间演化出其定性特征的,而不是在某单一线性时段内完成其演化的。这项研究提示,面部变更是尼安德特人演化的第一步。研究人员说,Sima de los Huesos人群看来是某包括尼安德特人在内的早期欧洲人世系的一部分,但它比后更新世的尼安德特人更为原始。此外,同一地质时期的其它化石与该Sima化石组中的化石不同,从而提示在中更新世时在不同人群之间存在着很大的差异。一篇《观点栏目》文章提出了更多的见解。

Abstract 

Seventeen Middle Pleistocene crania from the Sima de los Huesos site (Atapuerca, Spain) are analyzed, including seven new specimens. This sample makes it possible to thoroughly characterize a Middle Pleistocene hominin paleodeme and to address hypotheses about the origin and evolution of the Neandertals. Using a variety of techniques, the hominin-bearing layer could be reassigned to a period around 430,000 years ago. The sample shows a consistent morphological pattern with derived Neandertal features present in the face and anterior vault, many of which are related to the masticatory apparatus. This suggests that facial modification was the first step in the evolution of the Neandertal lineage, pointing to a mosaic pattern of evolution, with different anatomical and functional modules evolving at different rates.

Editor's Summary

Neandertal ancestors from Pleistocene Spain

The Sima de los Huesos site in Atapuerca, northern Spain, is a rich source of fossil hominin specimens. The site has now yielded further skull specimens that illuminate patterns of human evolution in Europe nearly half a million years ago. Arsuaga et al. studied 17 crania, including 7 that are new specimens and 6 that are more complete than before (see the Perspective by Hublin). This assemblage of specimens reveals the cranial, facial, and dental features of the Atapuerca hominins, which allows more precise evolutionary positioning of these Neandertal ancestors.

KEYWORDS

SHARE & LIKE

COMMENTS

ABOUT THE AUTHOR

Science

Science Magazine

0 Following 18 Fans 0 Projects 236 Articles

SIMILAR ARTICLES

AbstractThe conservation of sleep across all animal species suggests that sleep serves a vital function. We here report that sleep has a critical funct

Read More

Introduction Recent decades have seen a major international effort to inventory tree communities in the Amazon Basin and Guiana Shield (Amazonia), but

Read More

IntroductionInitiation of protein synthesis is a key step in the control of gene expression. In eukaryotes, initiation is a highly complex process that

Read More

Abstract For decades, social psychological theories have posited that the automatic processes captured by implicit measures have implications for soci

Read More

论文摘要动物界最复杂的眼睛可以在物种口足类甲壳动物(濑尿虾)中找到,其中一些有12种不同类型的光感受器,每种各取样较窄的一组波长,范围包含了深紫外光到远红光(300到720纳米)。在功能上,这种彩色复杂性被视作是谜。当3种或4种色彩通道对色彩辨认来说已经足够时,为何要使用12种色彩通道?对口足类动物行

Read More

论文摘要 首先,在一篇“评论”文章中,Thomas Piketty 和 Emmanuel Saez用“世界顶级收入数据库(WTID)”来比较这两个数值多年来是如何在欧洲和美国演变的;WTID包括了一个世纪之久的有关全球收入的数据以及2个世纪之久的有关个人财富的数据。据研究人员披露,在20世纪之交的时候

Read More

IntroductionCensorship has a long history in China, extending from the efforts of Emperor Qin to burn Confucian texts in the third century BCE to the c

Read More

Many animals, on air, water, or land, navigate in three-dimensional (3D) environments, yet it remains unclear how brain circuits encode the animal's 3D

Read More

Many animals, on air, water, or land, navigate in three-dimensional (3D) environments, yet it remains unclear how brain circuits encode the animal's 3D

Read More

Like mammalian neurons, Caenorhabditis elegans neurons lose axon regeneration ability as they age, but it is not known why. Here, we report that let-7

Read More