The Humans Behind The Myths: Investigating the Diffusion of Mythological Motifs with Genetic Data

Since the advent of Darwin’s theory of evolution, scholars in the humanities have tried to apply its principles to the transformation and spread of cultural traits. In particular, comparative mythologists have capitalised on the recent improvement of computational tools to design large databases on which to apply some of the frameworks developed by evolutionary biologists. However, few have integrated genetic data into their models, especially on a global scale. In this thesis, we make use of modern and ancient DNA sequences obtained from published sources as well as Yuri E. Berezkin’s Analytical Catalogue of World Mythology and Folklore, freely available online, to evaluate how mythological motifs might have been transmitted from one population to the other. We show that both cultural diffusion and demic movements are required to explain their distribution and that these processes were limited to some extent by linguistic barriers. We also note the preponderant role of population movement and replacement at smaller geographical scales, under 5,000 km. Furthermore, we applied our methodology to various subsets of motifs for which routes of dispersal following human migrations had been hypothesised in the literature. We found instead that isolation-by-distance seemed to better explain the observed pattern. On the other hand, focusing on motifs present at least in both America and Africa or in both Oceania and Africa increased the demic signal. Finally, capitalizing on the predictive power of demic and cultural models elaborated for each motif, we proposed a shortlist of those most likely to have travelled along humans’ migratory routes since the beginning of the Upper Paleolithic. Overall, our results highlight the interdisciplinary nature of molecular anthropology and its ability to contribute to humanistic studies, provided sufficiently thorough databases.