CULTURAL DIVERSIFICATION AND ACCELERATED PHENOTYPIC EVOLUTION: A CASE STUDY ON THE XAVÁNTE INDIANS

TÁBITA HUNEMEIER; JORGE GOMEZ-VALDÉS; MONICA BALLESTEROS-ROMERO; SOLEDAD DE AZEVEDO; NEUS MARTÍNEZ ABADÍAS; ESPARZA, MIREIA; SJOVOLD, TORSTEIN; SANDRO LUIS BONATTO; FRANCISCO MAURO SALZANO; MARIA-CATIRA BORTOLINI; ROLANDO GONZALEZ-JOSÉ

Burgos

Congreso; XVII World UISPP Congress; 2014

Union International de Sciences Préhistoriques e Protohistoriques

Changes 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 Xavante 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 Kayapo that occurred around 1,500 years ago. We also suggest that this rapid differentiation was possible due to strong social-organization differences that probably triggered reproductive isolation. 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 and/or social determinants. Assembling composite databases involving cultural and biological data will be of key importance to unravel cases of evolution modulated by the cultural environment.