一項發(fā)表在最新一期PNAS雜志上的研究"Cultural diversification promotes rapid phenotypic evolution in Xavánte Indians"發(fā)現(xiàn)，社會結(jié)構(gòu)和文化實踐的變化可能幫助驅(qū)動了人類的進化,。
Tábita Hünemeier及其同事比較了生活在巴西亞馬遜地區(qū)和中央高原的6個南美印地安人群的1203人的遺傳模式、地理,、氣候和身體特性,，這6個人群包括Xavánte、Kayapó, Baniwa,,、Ticuna,、Kaingang、Yanomama和Otomí人群 ,。后3個人群形成了近來分化出來的說Jê語言的單一群體,。對各個人群的頭部測量的詳細分析確定了Xavánte 是最分化的人群，比其他人群有更大的頭部,、更高更窄的臉,，以及更寬的鼻子。這些分析顯示這些分歧與氣候差異或者Xavánte人群與其他5個人群的地理分離無關,，但是可能反映了文化調(diào)控的隔離以及性選擇的組合,。
這組科研人員指出，此前的一項研究發(fā)現(xiàn)一個Xavánte村莊的1/4的人口是擁有5位妻子的同一個酋長的子孫,，這提示性選擇可能偏愛富有而且有地位的男性,，因此可能影響了Xavánte社會的進化。這組作者提出,，基因和文化可能共同進化,，而這種耦合可能在人類進化當中起到了支配作用。（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.
