The impact of group fissions on genetic structure in Native South America and implications for human evolution

Abstract

In a series of publications beginning in the 1960s, Neel and colleagues suggested that genetically nonrandom, or "lineal", population fissions contributed to genetic structure in ancient human groups. The authors reached this conclusion by studying the genetic consequences of village fissions among the Yanomamo, a Native South American group thought to have been relatively unaffected by European contact and, therefore, representative of the human past. On the basis of ethnographic accounts and pedigree data, they further concluded that patrilineal relationships were particularly important in shaping the genetic structure of villages following fissions. This study reexamines the genetic consequences of village fissions using autosomal STRs, Y-chromosome STRs, and mitochondrial DNA sequences collected from large samples of individuals from multiple Yanomamo villages. Our analyses of the autosomal STRs replicate the previous finding that village fissions have produced substantial genetic structure among the Yanomamo. However, our analyses of Y-chromosome STRs and mtDNA d-loop polymorphisms suggest that other population processes, including village movements, inter-village migration, and polygynous marriage, affect genetic structure in ways not predicted by a simple model of patrilineal fissions. We discuss the broader implications of population fissions for human evolution and the suitability of using the Yanomamo as a model for the human past.

Genetic structure in a dynamic baboon hybrid zone corroborates behavioural observations in a hybrid population

“…Behavioural observations that capture when an individual leaves its natal group, how far it goes and whether, when and with whom it mates, can therefore predict broader patterns of population genetic structure and provide insight into its underlying causes (see, for example, Holekamp et al 2011;Kerth & van Schaik 2011;Ribeiro et al 2011). For example, endogamous marriage patterns among humans in India partially explain high levels of population structure on the Indian subcontinent ), and practices of residency after marriage have been shown to yield contrasting patterns of structure in Y-chromosome and mitochondrial DNA in culturally diverse human populations (Oota et al 2001;Wilder et al 2004;Wilkins 2006;Hunley et al 2008;Crubezy et al 2010).…”

Exploring the mitochondrial DNA variability of the Amazonian Yanomami

“…This study also reveals that there is genetic differentiation among Yanomami populations, probably as consequence of different population processes that affected them (Hunley et al, 2008). This study also reveals that there is genetic differentiation among Yanomami populations, probably as consequence of different population processes that affected them (Hunley et al, 2008).…”

“…The sociocultural aspects of this population are widely described in the literature, and several groups have been genetically characterized (Early and Peters, 2000;Fagundes et al, 2002;Hunley et al, 2008;Melancon, 1982;Merriwether et al, 2000;Migliazza, 1972;Smole, 1976;Thomas, 2001;Torroni et al, 1993;Williams et al, 2002). The sociocultural aspects of this population are widely described in the literature, and several groups have been genetically characterized (Early and Peters, 2000;Fagundes et al, 2002;Hunley et al, 2008;Melancon, 1982;Merriwether et al, 2000;Migliazza, 1972;Smole, 1976;Thomas, 2001;Torroni et al, 1993;Williams et al, 2002).…”

New developments in the origins and evolution of Native American populations

“…Moreover, groups of related individuals form the units of diffusion among local groups. Kin-structured migration subsequently became a basic component of human genetic demography (Fix, 1978(Fix, , 2004Smouse et al, 1981;Rogers, 1987;Hunley et al, 2008). Another ground breaking conclusion from Dr. Salzano's studies on Native American genetic diversity was that the amount of genetic variability in a small inbred tribe comes close to that in contemporary urban populations (Neel and Salzano, 1967).…”