Abstract
In a previous study, we proposed a model for genetic admixture
between African hunter-gatherers and food producers, in which we integrated
demographic and genetic aspects together with ethnographic knowledge
(Destro Bisol et al. 2004b). In that study it was possible to test the model only
using genetic information from widely dispersed and genetically heterogeneous
populations. Here we reevaluate the congruence between the model and patterns
of genetic variation using an anthropologically and geographically more
homogeneous data set that includes Pygmies and farmers from Cameroon,
Congo, and the Central African Republic. As implied by the model, the ratios
of mtDNA to Y chromosome Nm estimates (effective population size, N, times
the migration rate, m; 0.154 in Pygmies and 6.759 in farmers), support an
asymmetric gene flow, with a higher Pygmy-to-Pygmy gene flow for paternal
than for maternal lineages, and vice versa for farmers. Analyses of intra- and
interpopulation genetic variation further support the above observation, showing
a prevailing effect of genetic drift on maternal lineages and gene flow on
paternal lineages among Pygmies, and an opposite pattern among farmers. We
also detected differences between patterns for classical and molecular measures
of Y chromosome intrapopulation variation, which likely represent signatures
of the introgression of Bantu lineages into the gene pool of Pygmy populations.
On the whole, our results seem to reflect differences in the demographic history
and the degree of patrilocality and polygyny between the two population
groups, thus providing further support to our microevolutionary model in an
anthropologically coherent framework.
Lingua originale | English |
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pagine (da-a) | 581-591 |
Numero di pagine | 11 |
Rivista | Human Biology |
Stato di pubblicazione | Pubblicato - 2013 |
Keywords
- Y chromosome
- mtDNA