A diffusion based study of population dynamics: Prehistoric migrations into South Asia.

Mayank N Vahia,Deepak Mathur,Uma Ladiwala,Nisha Yadav,Chuan-Chao Wang

doi:10.1371/journal.pone.0176985

Mayank N Vahia, Deepak Mathur + Show 3 more

Open Access

https://doi.org/10.1371/journal.pone.0176985

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Journal: PloS one	Publication Date: May 11, 2017
Citations: 3	License type: CC BY 4.0

Affiliation: Tata Institute of Fundamental Research

Abstract

A diffusion equation has been used to study migration of early humans into the South Asian subcontinent. The diffusion equation is tempered by a set of parameters that account for geographical features like proximity to water resources, altitude, and flatness of land. The ensuing diffusion of populations is followed in time-dependent computer simulations carried out over a period of 10,000 YBP. The geographical parameters are determined from readily-available satellite data. The results of our computer simulations are compared to recent genetic data so as to better correlate the migratory patterns of various populations; they suggest that the initial populations started to coalesce around 4,000 YBP before the commencement of a period of relative geographical isolation of each population group. The period during which coalescence of populations occurred appears consistent with the established timeline associated with the Harappan civilization and also, with genetic admixing that recent genetic mapping data reveal. Our results may contribute to providing a timeline for the movement of prehistoric people. Most significantly, our results appear to suggest that the Ancestral Austro-Asiatic population entered the subcontinent through an easterly direction, potentially resolving a hitherto-contentious issue.

Highlights

The primary drivers for prehistoric human migrations have been geography and availability of natural resources [1]
Korisettar [32] has identified core areas of paleolithic occupation in the subcontinent which are consistent with the model proposed by Reich and coworkers [5] wherein most extant populations of India result from admixture between Ancestral North Indian (ANI) and Ancestral South Indian (ASI) [5, 13]
In this context it is important to note that relative insensitivity to the precise initial location of populations was checked by us vis-a-vis ANI ingress: we substituted Balkh by locations corresponding to Mohenjodaro and Harappa and the results of our diffusion process was essentially unaltered over the 10,000 year period

Summary

Introduction

The primary drivers for prehistoric human migrations have been geography and availability of natural resources [1]. These are deterministic parameters when small populations relocate to newer territories under conditions in which conflicts and large group dynamics are inconsequential. We make use of high resolution topographical and hydro-shed data from readily accessible satellite databases to define these habitability parameters. This enables us to simulate the diffusion of populations based on human preference for more habitable places, with the rate of movement tempered by existing populations.

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Results

Conclusion