Across language families: Genome diversity mirrors linguistic variation withinEurope

Abstract

Objectives: The notion that patterns of linguistic and biological variation may cast light on each other and on population histories dates back to Darwin's times; yet, turning this intuition into a proper research program has met with serious methodological difficulties, especially affecting language comparisons. This article takes advantage of two new tools of comparative linguistics: a refined list of Indo‐European cognate words, and a novel method of language comparison estimating linguistic diversity from a universal inventory of grammatical polymorphisms, and hence enabling comparison even across different families. We corroborated the method and used it to compare patterns of linguistic and genomic variation in Europe. Materials and Methods: Two sets of linguistic distances, lexical and syntactic, were inferred from these data and compared with measures of geographic and genomic distance through a series of matrix correlation tests. Linguistic and genomic trees were also estimated and compared. A method (Treemix) was used to infer migration episodes after the main population splits. Results: We observed significant correlations between genomic and linguistic diversity, the latter inferred from data on both Indo‐European and non‐Indo‐European languages. Contrary to previous observations, on the European scale, language proved a better predictor of genomic differences than geography. Inferred episodes of genetic admixture following the main population splits found convincing correlates also in the linguistic realm. Discussion: These results pave the ground for previously unfeasible cross‐disciplinary analyses at the worldwide scale, encompassing populations of distant language families. Am J Phys Anthropol 157:630–640, 2015. © 2015 Wiley Periodicals, Inc.

Tracking modern human population history from linguistic and cranial phenotype

“…Although grammar data are not currently available for the populations we sampled, recent studies have found a strong association between genes and grammar data for populations within Europe56 and across Europe, Africa, and Western Asia57. It has previously been hypothesized3458 that grammatical rate of change is more comparable to the rate of change of some genetic systems than to that of others, which has been partly supported for a sample of populations from Eurasia and Africa57.…”

Gene-culture co-inheritance of a behavioral trait

“…Unfortunately, these results say little about the within-group variance in culture relative to genes. Other studies have shown parallels in the patterns of linguistic and genetic diversity (Perreault and Mathew, 2012; Longobardi et al, 2015; Creanza et al, 2015; Hunley et al, 2008), but again provided no information about the ratio of genetic to cultural variance. However, this question is well-suited to empirical study; given our results, empirical estimates of the ratio can shed light on qualitative expectations about the evolution of behavioral traits.…”

An interview on linguistic variation with Giuseppe Longobardi

“…It is a plausible guess that as syntax should be free from the arbitrariness of lexical meanings, it should also be less directly influenced by the variability of culture. Of course, if we find that genetic diversity and syntactic diversity are measurably correlated with each other in a significant way (Longobardi et al 2015), without there being direct causation between the two variables, then it is possible that differences in other cultural features (say, laws, culinary traditions etc.) may also interestingly correlate with language diversity.…”