一项发表在最新一期PNAS杂志上的研究"Cultural diversification promotes rapid phenotypic evolution in Xavánte Indians"发现，社会结构和文化实践的变化可能帮助驱动了人类的进化。
Tábita Hünemeier及其同事比较了生活在巴西亚马逊地区和中央高原的6个南美印地安人群的1203人的遗传模式、地理、气候和身体特性，这6个人群包括Xavánte、Kayapó, Baniwa,、Ticuna、Kaingang、Yanomama和Otomí人群 。后3个人群形成了近来分化出来的说Jê语言的单一群体。对各个人群的头部测量的详细分析确定了Xavánte 是最分化的人群，比其他人群有更大的头部、更高更窄的脸，以及更宽的鼻子。这些分析显示这些分歧与气候差异或者Xavánte人群与其他5个人群的地理分离无关，但是可能反映了文化调控的隔离以及性选择的组合。
这组科研人员指出，此前的一项研究发现一个Xavánte村庄的1/4的人口是拥有5位妻子的同一个酋长的子孙，这提示性选择可能偏爱富有而且有地位的男性，因此可能影响了Xavánte社会的进化。这组作者提出，基因和文化可能共同进化，而这种耦合可能在人类进化当中起到了支配作用。（生物谷Bioon.com）
doi:10.1073/pnas.1118967109
PMC:
PMID:
Cultural diversification promotes rapid phenotypic evolution in Xavánte Indians
Tábita Hünemeiera, Jorge Gómez-Valdésb, Mónica Ballesteros-Romeroc, Soledad de Azevedod, Neus Martínez-Abadíase, Mireia Esparzaf, Torstein Sj?voldg, Sandro L. Bonattoh,
et al.
Shifts in social structure and cultural practices can potentially promote unusual combinations of allele frequencies that drive the evolution of genetic and phenotypic novelties during human evolution. These cultural practices act in combination with geographical and linguistic barriers and can promote faster evolutionary changes shaped by gene–culture interactions. However, specific cases indicative of this interaction are scarce. Here we show that quantitative genetic parameters obtained from cephalometric data taken on 1,203 individuals analyzed in combination with genetic, climatic, social, and life-history data belonging to six South Amerindian populations are compatible with a scenario of rapid genetic and phenotypic evolution, probably mediated by cultural shifts. We found that the Xavánte experienced a remarkable pace of evolution: the rate of morphological change is far greater than expected for its time of split from their sister group, the Kayapó, which occurred around 1,500 y ago. We also suggest that this rapid differentiation was possible because of strong social-organization differences. Our results demonstrate how human groups deriving from a recent common ancestor can experience variable paces of phenotypic divergence, probably as a response to different cultural or social determinants. We suggest that assembling composite databases involving cultural and biological data will be of key importance to unravel cases of evolution modulated by the cultural environment.
