Landscape genetics and the genetic legacy of Upper Paleolithic and Mesolithic hunter-gatherers in the modern Caucasus

Alexander Gavashelishvili,Alexey Yanchukov,Marine Murtskhvaladze,Ceren Kazancı,David Tarkhnishvili,Irakli Akhvlediani

doi:10.1038/s41598-021-97519-6

Abstract

This study clarifies the role of refugia and landscape permeability in the formation of the current genetic structure of peoples of the Caucasus. We report novel genome-wide data for modern individuals from the Caucasus, and analyze them together with available Paleolithic and Mesolithic individuals from Eurasia and Africa in order (1) to link the current and ancient genetic structures via landscape permeability, and (2) thus to identify movement paths between the ancient refugial populations and the Caucasus. The ancient genetic ancestry is best explained by landscape permeability implying that human movement is impeded by terrain ruggedness, swamps, glaciers and desert. Major refugial source populations for the modern Caucasus are those of the Caucasus, Anatolia, the Balkans and Siberia. In Rugged areas new genetic signatures take a long time to form, but once they do so, they remain for a long time. These areas act as time capsules harboring genetic signatures of ancient source populations and making it possible to help reconstruct human history based on patterns of variation today.

Highlights

The Caucasus is a mountainous region located on the dividing line between Europe and Asia, between the Black and Caspian seas
The Caucasus provided some of the globe’s important refugia, where most of the terrestrial plants and animals survived during a series of glacial maxima, and their current distribution largely reflects post-glacial expansion from these refugia[1]. These glacial refugia and the barriers to migration played an important role in human evolution, and generated much of the human genetic and ethno-linguistic patterns found in the world today[4,5,6,7]
Our results suggest that the current populations of the Caucasus bear detectable ancestry from Caucasian, Anatolian and Balkan hunter-gatherers

Summary

Introduction

The Caucasus is a mountainous region located on the dividing line between Europe and Asia, between the Black and Caspian seas. In spite of relatively small geographic extent and mostly temperate climate, the diversity of natural landscapes, plant and animal species, and cultivars is unusually high in the Caucasus[1]. Thanks to this diversity the Caucasus is one of the global biodiversity hotspots that contain considerable linguistic diversity, accounting for most of all languages on E arth[2,3]. Autosomal genome and mtDNA variations in the Caucasus appear relatively homogenous, while the Y-chromosome diversity clearly shows geographic heterogeneity distinguishing the eastern from western Caucasians[7,17,24].

Methods

Results

Conclusion