Evidence of the interplay of genetics and culture in Ethiopia

Saioa López,Ephrem Mekonnen,Neil Bradman,Roger Blench,Mark G Thomas,Nancy Bird,Tamiru Oljira,Endashaw Bekele,Gavin Band,Garrett Hellenthal,Sam Morris,Ayele Tarekegn,Lucy Van Dorp

doi:10.1038/s41467-021-23712-w

Abstract

The rich linguistic, ethnic and cultural diversity of Ethiopia provides an unprecedented opportunity to understand the level to which cultural factors correlate with–and shape–genetic structure in human populations. Using primarily new genetic variation data covering 1,214 Ethiopians representing 68 different ethnic groups, together with information on individuals’ birthplaces, linguistic/religious practices and 31 cultural practices, we disentangle the effects of geographic distance, elevation, and social factors on the genetic structure of Ethiopians today. We provide evidence of associations between social behaviours and genetic differences among present-day peoples. We show that genetic similarity is broadly associated with linguistic affiliation, but also identify pronounced genetic similarity among groups from disparate language classifications that may in part be attributable to recent intermixing. We also illustrate how groups reporting the same culture traits are more genetically similar on average and show evidence of recent intermixing, suggesting that shared cultural traits may promote admixture. In addition to providing insights into the genetic structure and history of Ethiopia, we identify the most important cultural and geographic predictors of genetic differentiation and provide a resource for designing sampling protocols for future genetic studies involving Ethiopians.

Highlights

The rich linguistic, ethnic and cultural diversity of Ethiopia provides an unprecedented opportunity to understand the level to which cultural factors correlate with–and shape–genetic structure in human populations
To measure genetic similarity between pairs of individuals, we calculated the total variation distance (TVD)[43] between their haplotype-sharing patterns inferred by CHROMOPAINTER63
TVD estimates have been shown to be more powerful at distinguishing subtle genetic differences among e.g., African groups[65]

Summary

Introduction

The rich linguistic, ethnic and cultural diversity of Ethiopia provides an unprecedented opportunity to understand the level to which cultural factors correlate with–and shape–genetic structure in human populations. Using primarily new genetic variation data covering 1,214 Ethiopians representing 68 different ethnic groups, together with information on individuals’ birthplaces, linguistic/religious practices and 31 cultural practices, we disentangle the effects of geographic distance, elevation, and social factors on the genetic structure of Ethiopians today. We provide evidence of associations between social behaviours and genetic differences among present-day peoples. We show that genetic similarity is broadly associated with linguistic affiliation, and identify pronounced genetic similarity among groups from disparate language classifications that may in part be attributable to recent intermixing. We illustrate how groups reporting the same culture traits are more genetically similar on average and show evidence of recent intermixing, suggesting that shared cultural traits may promote admixture.

Methods

Results

Conclusion