title: Detecting genetic isolation in human populations: a study of European language minorities.
abstract: The identification of isolation signatures is fundamental to better understand the genetic structure of human populations and to test the relations between cultural factors and genetic variation. However, with current approaches, it is not possible to distinguish between the consequences of long-term isolation and the effects of reduced sample size, selection and differential gene flow. To overcome these limitations, we have integrated the analysis of classical genetic diversity measures with a bayesian method to estimate gene flow and have carried out simulations based on the coalescent. Combining these approaches, we first tested whether the relatively short history of cultural and geographical isolation of four "linguistic islands" of the Eastern Alps (Lessinia, Sauris, Sappada and Timau) had left detectable signatures in their genetic structure. We then compared our findings to previous studies of European population isolates. Finally, we explored the importance of demographic and cultural factors in shaping genetic diversity among the groups under study. A combination of small initial effective size and continued genetic isolation from surrounding populations seems to provide a coherent explanation for the diversity observed among Sauris, Sappada and Timau, which was found to be substantially greater than in other groups of European isolated populations. Simulations of micro-evolutionary scenarios indicate that ethnicity might have been important in increasing genetic diversity among these culturally related and spatially close populations.
authors: Dipartimento Biologia e Biotecnologie Charles Darwin, Università La Sapienza, Rome, Italy.
authors: Marco
authors: M
authors: Capocasa
authors: Cinzia
authors: C
authors: Battaggia
authors: Paolo
authors: P
authors: Anagnostou
authors: Francesco
authors: F
authors: Montinaro
authors: Ilaria
authors: I
authors: Boschi
authors: Gianmarco
authors: G
authors: Ferri
authors: Milena
authors: M
authors: Alù
authors: Valentina
authors: V
authors: Coia
authors: Federica
authors: F
authors: Crivellaro
authors: Giovanni
authors: G
authors: Destro Bisol
mesh_terms: D001499:Bayes Theorem; D041322:Chromosomes, Human, Y / Q000235:genetics; D003198:Computer Simulation; D004272:DNA, Mitochondrial / Q000235:genetics; D005006:Ethnicity / Q000235:genetics; D019143:Evolution, Molecular; D005260:Female; D051456:Gene Flow; D005787:Gene Frequency; D014644:Genetic Variation; D005828:Genetics, Population / Q000379:methods*; D005843:Geography; D006239:Haplotypes; D006801:Humans; D007802:Language; D008297:Male; D008913:Minority Groups; D008957:Models, Genetic; D044465:White People / Q000235:genetics*
chemical_list: D004272:DNA, Mitochondrial