Abstract
Language diversity is distributed unevenly over the globe. Intriguingly, patterns of language diversity resemble biodiversity patterns, leading to suggestions that similar mechanisms may underlie both linguistic and biological diversification. Here we present the first global analysis of language diversity that compares the relative importance of two key ecological mechanisms – isolation and ecological risk – after correcting for spatial autocorrelation and phylogenetic non-independence. We find significant effects of climate on language diversity, consistent with the ecological risk hypothesis that areas of high year-round productivity lead to more languages by supporting human cultural groups with smaller distributions. Climate has a much stronger effect on language diversity than landscape features, such as altitudinal range and river density, which might contribute to isolation of cultural groups. The association between biodiversity and language diversity appears to be an incidental effect of their covariation with climate, rather than a causal link between the two.
Highlights
Language diversity is distributed unevenly over the globe
We find no evidence supporting a direct link between biological diversity and language diversity[25,26,30,31], showing that this association is more likely owing to covariation of both biodiversity and language diversity with climatic factors and landscape features
Our analyses were based on global-scale datasets of the geographic distribution of 6425 languages[1], high-resolution climatic and geographic data layers, and global biodiversity datasets
Summary
Language diversity is distributed unevenly over the globe. Intriguingly, patterns of language diversity resemble biodiversity patterns, leading to suggestions that similar mechanisms may underlie both linguistic and biological diversification. We find significant effects of climate on language diversity, consistent with the ecological risk hypothesis that areas of high year-round productivity lead to more languages by supporting human cultural groups with smaller distributions. Climate has a much stronger effect on language diversity than landscape features, such as altitudinal range and river density, which might contribute to isolation of cultural groups. Two broad kinds of ecological mechanism have been offered to explain geographic variation in language diversity: isolation and ecological risk. Isolation mechanisms are associated with landscape and geographic features that act as barriers to human movement Such physical barriers may reduce interaction between groups, slowing the spread of linguistic variants among neighboring populations, leading to the accumulation of language changes that distinguish each language from its neighbors[12]. The ecological risk mechanism for language diversity predicts an association between language diversity and climatic factors such as seasonal temperature variation and yearly rainfall[16,17,18,19]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
