North African Populations Carry the Signature of Admixture with Neandertals
Federico Sánchez-Quinto1#, Laura R. Botigué1#, Sergi Civit3, Conxita Arenas3, María C. Ávila-Arcos4, Carlos D. Bustamante2, David Comas1¶, Carles Lalueza-Fox1¶*
1 Institut de Biologia Evolutiva (CSIC-Universitat Pompeu Fabra), Barcelona, Spain, 2 Department of Genetics, Stanford University, Stanford, California, United States of America, 3 Departament d'Estadística, Universitat de Barcelona, Barcelona, Spain, 4 Centre for GeoGenetics, Natural History Museum of Denmark, University of Copenhagen, Copenhagen, Denmark
Abstract
One of the main findings derived from the analysis of the Neandertal genome was the evidence for admixture between Neandertals and non-African modern humans. An alternative scenario is that the ancestral population of non-Africans was closer to Neandertals than to Africans because of ancient population substructure. Thus, the study of North African populations is crucial for testing both hypotheses. We analyzed a total of 780,000 SNPs in 125 individuals representing seven different North African locations and searched for their ancestral/derived state in comparison to different human populations and Neandertals. We found that North African populations have a significant excess of derived alleles shared with Neandertals, when compared to sub-Saharan Africans. This excess is similar to that found in non-African humans, a fact that can be interpreted as a sign of Neandertal admixture. Furthermore, the Neandertal's genetic signal is higher in populations with a local, pre-Neolithic North African ancestry. Therefore, the detected ancient admixture is not due to recent Near Eastern or European migrations. Sub-Saharan populations are the only ones not affected by the admixture event with Neandertals.
Citation: Sánchez-Quinto F, Botigué LR, Civit S, Arenas C, Ávila-Arcos MC, et al. (2012) North African Populations Carry the Signature of Admixture with Neandertals. PLoS ONE 7(10): e47765. doi:10.1371/journal.pone.0047765
Editor: David Caramelli, University of Florence, Italy
Received: July 17, 2012; Accepted: September 20, 2012; Published: October 17, 2012
Copyright: © 2012 Sánchez-Quinto 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.
Funding: FS-Q, SC, CA and CL-F are supported by a grant from the Ministerio de Ciencia e Innovación of Spain (BFU2009-06974) and CGL2010-14944/BOS. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing interests: The authors have declared that no competing interests exist.
* E-mail: carles.lalueza@upf.edu
# These authors contributed equally to this work.
¶ These authors also contributed equally to this work.
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