A three-population wave-of-advance model for the European early Neolithic.

Kenichi Aoki,Ron Pinhasi

doi:10.1371/journal.pone.0233184

Abstract

Ancient DNA studies have shown that early farming spread through most of Europe by the range expansion of farmers of Anatolian origin rather than by the conversion to farming of the local hunter-gatherers, and have confirmed that these hunter-gatherers continued to coexist with the incoming farmers. In this short report, I extend a previous three-population wave-of-advance model to accommodate these new findings, and derive the conditions supportive of such a scenario in terms of the relative magnitudes of the parameters. The revised model predicts that the conversion rate must, not surprisingly, be low, but also that the hunter-gatherers must compete more strongly with the converted farmers than with the alien farmers. Moreover, competition with the hunter-gatherers diminishes the speed of the wave-of advance of the farmers. In addition, I briefly consider how the wave-of-advance approach may contribute to interpreting the results of archaeological studies using the summed probability distribution of radiocarbon dates.

Highlights

A longstanding question with regard to the spread of early farming in Europe is whether it occurred by the range expansion of farmers of Near Eastern origin or by the iterative conversion to farming of the local hunter-gatherers
Valdiosera et al [5] estimate the genetic contributions of western hunter-gatherers, early Anatolian farmers, and Yamnaya by a three-way admixture analysis and show that early Neolithic individuals from the north and south of Spain have greater than 95% Anatolian ancestry, with a small remaining contribution from the western hunter-gatherers
Recent genetic studies of ancient DNA have shown that early farming spread through Europe principally by the demic expansion of farmers of Anatolian origin rather than by cultural diffusion

Summary

Introduction

A longstanding question with regard to the spread of early farming in Europe is whether it occurred by the range expansion of farmers of Near Eastern origin or by the iterative conversion to farming of the local hunter-gatherers. None of the four classes of solutions predicted the steady range expansion of the initial farmers of Near Eastern descent that is coupled with the persistence of the hunter-gatherers, which is what is suggested by the ancient DNA data. The main purpose of the present paper is to revise the model of Aoki et al [24] to be qualitatively consistent with our current understanding of the Neolithic transition in Europe and to address the limited question of the wave profile or composition of the traveling wave solutions, whether the wave front of the spread of farming will be dominated by the initial farmers, and whether the hunter-gatherers will persist in the wake of the wave. I suggest that the relevant traveling wave solution may provide a suitable null hypothesis for interpreting the results of archaeological studies using the so-called summed probability distribution of radiocarbon dates, e.g. [30, 31]

Revised model

Ad hoc analysis

Discussion

Findings

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