Bycroft, ClareFernández Rozadilla, CeresRuiz Ponte, ClaraQuintela García, InésCarracedo Álvarez, ÁngelMyers, Simon2020-04-062020-04-062019Bycroft, C., Fernandez-Rozadilla, C., Ruiz-Ponte, C. et al. Patterns of genetic differentiation and the footprints of historical migrations in the Iberian Peninsula. Nat Commun 10, 551 (2019). https://doi.org/10.1038/s41467-018-08272-whttp://hdl.handle.net/10347/21184The Iberian Peninsula is linguistically diverse and has a complex demographic history, including a centuries-long period of Muslim rule. Here, we study the fine-scale genetic structure of its population, and the genetic impacts of historical events, leveraging powerful, haplotype-based statistical methods to analyse 1413 individuals from across Spain. We detect extensive fine-scale population structure at extremely fine scales (below 10 Km) in some regions, including Galicia. We identify a major east-west axis of genetic differentiation, and evidence of historical north to south population movement. We find regionally varying fractions of north-west African ancestry (0–11%) in modern-day Iberians, related to an admixture event involving European-like and north-west African-like source populations. We date this event to 860–1120 CE, implying greater genetic impacts in the early half of Muslim rule in Iberia. Together, our results indicate clear genetic impacts of population movements associated with both the Muslim conquest and the subsequent Reconquista.eng© The Author(s) 2019. Open Access. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/ licenses/by/4.0https://creativecommons.org/licenses/by/4.0/journal article10.1038/s41467-018-08272-w2041-1723open access