Inferring patterns of folktale diffusion using genomic data

Bortolini, Eugenio; Pagani, Luca; Crema, Enrico R.; Sarno, Stefania; Barbieri, Chiara; Boattini, Alessio; Sazzini, Marco; da Silva, Sara Graça; Martini, Gessica; Metspalu, Mait; Pettener, Davide; Luiselli, Donata; Tehrani, Jamshid J.

Abstract

Observable patterns of cultural variation are consistently intertwined with demic movements, cultural diffusion, and adaptation to different ecological contexts [Cavalli-Sforza and Feldman (1981) Cultural Transmission and Evolution: A Quantitative Approach; Boyd and Richerson (1985) Culture and the Evolutionary Process]. The quantitative study of gene–culture coevolution has focused in particular on the mechanisms responsible for change in frequency and attributes of cultural traits, the spread of cultural information through demic and cultural diffusion, and detecting relationships between genetic and cultural lineages. Here, we make use of worldwide whole-genome sequences [Pagani et al. (2016) Nature 538:238–242] to assess the impact of processes involving population movement and replacement on cultural diversity, focusing on the variability observed in folktale traditions (n = 596) [Uther (2004) The Types of International Folktales: A Classification and Bibliography. Based on the System of Antti Aarne and Stith Thompson] in Eurasia. We find that a model of cultural diffusion predicted by isolation-by-distance alone is not sufficient to explain the observed patterns, especially at small spatial scales (up to ∼∼4,000 km). We also provide an empirical approach to infer presence and impact of ethnolinguistic barriers preventing the unbiased transmission of both genetic and cultural information. After correcting for the effect of ethnolinguistic boundaries, we show that, of the alternative models that we propose, the one entailing cultural diffusion biased by linguistic differences is the most plausible. Additionally, we identify 15 tales that are more likely to be predominantly transmitted through population movement and replacement and locate putative focal areas for a set of tales that are spread worldwide.

Citation

Bortolini, E., Pagani, L., Crema, E. R., Sarno, S., Barbieri, C., Boattini, A., …Tehrani, J. J. (2017). Inferring patterns of folktale diffusion using genomic data. Proceedings of the National Academy of Sciences, 114(34), 9140-9145. https://doi.org/10.1073/pnas.1614395114

• Journal Article Type: Article
• Acceptance Date: Jun 13, 2017
• Online Publication Date: Aug 7, 2017
• Publication Date: Aug 22, 2017
• Deposit Date: Aug 10, 2017
• Publicly Available Date: Feb 7, 2018
• Journal: Proceedings of the National Academy of Sciences
• Print ISSN: 0027-8424
• Electronic ISSN: 1091-6490
• Publisher: National Academy of Sciences
• Peer Reviewed: Peer Reviewed
• Volume: 114
• Issue: 34
• Pages: 9140-9145
• DOI: https://doi.org/10.1073/pnas.1614395114
• Public URL: https://durham-repository.worktribe.com/output/1379486