Complex genetic patterns in human arise from a simple range-expansion model over continental landmasses

Kanitz, Ricardo; Guillot, Elsa; Antoniazza, Sylvain; Neuenschwander, Samuel; Goudet, J�r�me

Abstract

© 2018 Kanitz et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Although it is generally accepted that geography is a major factor shaping human genetic differentiation, it is still disputed how much of this differentiation is a result of a simple process of isolation-by-distance, and if there are factors generating distinct clusters of genetic similarity. We address this question using a geographically explicit simulation framework coupled with an Approximate Bayesian Computation approach. Based on six simple summary statistics only, we estimated the most probable demographic parameters that shaped modern human evolution under an isolation by distance scenario, and found these were the following: an initial population in East Africa spread and grew from 4000 individuals to 5.7 million in about 132 000 years. Subsequent simulations with these estimates followed by cluster analyses produced results nearly identical to those obtained in real data. Thus, a simple diffusion model from East Africa explains a large portion of the genetic diversity patterns observed in modern humans. We argue that a model of isolation by distance along the continental landmasses might be the relevant null model to use when investigating selective effects in humans and probably many other species.

• Journal Article Type: Article
• Acceptance Date: Jan 23, 2018
• Online Publication Date: Jan 21, 2018
• Publication Date: Feb 21, 2018
• Deposit Date: Feb 28, 2018
• Publicly Available Date: Feb 28, 2018
• Journal: PLoS ONE
• Electronic ISSN: 1932-6203
• Publisher: Public Library of Science
• Peer Reviewed: Peer Reviewed
• Volume: 13
• Issue: 2
• Article Number: e0192460
• DOI: https://doi.org/10.1371/journal.pone.0192460
• Keywords: complex genetic patterns, human, simple range-expansion model, continental landmasses
• Public URL: https://uwe-repository.worktribe.com/output/874764
• Publisher URL: http://dx.doi.org/10.1371/journal.pone.0192460
• Contract Date: Feb 28, 2018