Genetic, geographic, and linguistic distances in Europe.

Abstract

Genetic and taxonomic distances were computed for 3466 samples of human populations in Europe based on 97 allele frequencies and 10 cranial variables. Since the actual samples employed differed among the genetic systems studied, the genetic distances were computed separately for each system, as were matrices of geographic distances and of linguistic distances based on membership in the same language family or phylum. Significant matrix correlations between genetics and geography were found for the majority of systems; somewhat less frequent are significant correlations between genetics and language. The effects of the two factors can be separated by means of partial matrix correlations.These show significant values for both genetics and geography, language kept constant, and genetics and language, geography kept constant, with a tendency for the former to be higher. These findings demonstrate that speakers of different language families in Europe differ genetically and that this difference remains even after geographic differentiation is allowed for. The greater effect of geography than of language may be due to the several factors that bring about spatial differentiation in human populations.A continuing problem in population biology is to estimate and explain genetic differences among the populations constituting a species. Such differences are generally measured as genetic distances (1-3). At the level of local populations, random differentiation has generally been invoked as a null model for explaining the observed differences among sampling units. Such differentiation is due to sampling errors from gene pools of limited size (genetic drift; see refs. 2, 4) and to the limited mobility of individuals within the area of study (isolation by distance; see refs. 2, 5, 6). Models have been proposed that explain the amount of differentiation in terms of distance among sampling units (7-9). Microevolutionary forces that complicate the realization of a straightforward spatial differentiation model are selection and directed migration (as distinct from the random dispersal of individuals underlying the isolation-by-distance model).When genetic variation is studied on a continental scale, as in the present paper, another factor-history-may be responsible for some of the variation. Populations that differentiated elsewhere may undertake long-range directed migration and settle in a part of the area under study, displacing or genetically absorbing the previous residents. Such a process disturbs what might otherwise be a simple relation between genetic and geographic distance. In humans, we have evidence from historical sources that such migrations have indeed taken place. Some are well known; others are inferred with greater or lesser certainty from archeological and prehistorical information. In animal and plant populations, such occurrences may be far more difficult to detect. It is of interest, therefore, to examine genetic differences in humans, where some estimate of the relative time of separation of the ...

Across language families: Genome diversity mirrors linguistic variation withinEurope

“…Reliable evidence for parallelism of genetic and linguistic change had previously been provided, although only on a regional scale (Sokal, 1988) and without formal quantification of language distances. Here, first through a quantitative approach to cognate words (Bouckaert et al, 2012), and then through a syntactic method (the PCM, Longobardi and Guardiano, 2009) designed for comparing languages across separate families, we overcome both limits of previous studies.…”

“…Sokal (1988) and Cavalli‐Sforza et al (1988) could venture into addressing Darwin's gene‐language congruence issue thanks to the theoretical progress of 20th century genetics; along with the availability of broad genomic datasets, the corresponding progress of formal grammatical theory over the past 50 years may now enable us to accurately test the hypothesis on ever larger and more solid grounds.…”

“…Darwin's evolutionary framework was immediately accepted by linguists such as Schleicher (1863); however, it took more than a century for his parallelism intuition to be tried against actual data (Sokal, 1988; Cavalli‐Sforza et al, 1988), and to become part of a broader research program (Renfrew, 1987; Cavalli Sforza et al, 1994). The idea is that linguistic diversification caused by demographic processes, mainly population dispersal, would generate parallel patterns of genetic and linguistic variation.…”

Genetic Evidence for Complexity in Ethnic Differentiation and History in East Africa

“…This expectation is partly met with the correlation between genetic differentiation and language affiliation that is found at both large (CavalliSforza et al, 1988;Sokal, 1988;Excoffier et al, 1991;Chen et al, 1995;Poloni et al, 1997Poloni et al, , 2005Sanchez-Mazas et al, 2005;Wood et al, 2005;Belle & Barbujani, 2007) and fine scales (Friedlaender et al, 2007;Lansing et al, 2007;Hassan et al, 2008). However, examples of populations that do not fit this expectation exist, where the genetic diversity shows clear signatures of genetic exchange between culturally different groups (Langaney & Gomila, 1973;Blanc et al, 1990;Chaix et al, 2004).…”

Genetic Distance Measures: Review

“…Such differences are generally measured as genetic distances. 1 Genetic distances have frequently been used in assessments of species status of closely related taxa and in a diversity of evolutionary studies. The objective measurement of the similarity between populations has concerned geneticists, taxonomists, anthropologists, and plant and animal breeders for a long time.…”