Maioria dos homens europeus modernos descende de agricultores que migraram do Oriente Médio

sábado, janeiro 23, 2010

Most Modern European Males Descend from Farmers Who Migrated from the Near East

ScienceDaily (Jan. 21, 2010) — A new study from the University of Leicester has found that most men in Europe descend from the first farmers who migrated from the Near East 10,000 years ago. The findings are published January 19 in the open-access journal PLoS Biology.





Maps showing dates of the spread of early farming in Europe, and the frequency and microsatellite variance of haplogroup R1b1b2. (Credit: Balaresque P, Bowden GR, Adams SM, Leung H-Y, King TE, et al. A Predominantly Neolithic Origin for European Paternal Lineages. PLoS Biol, 8(1):e1000285 DOI: 10.1371/journal.pbio.1000285)

The invention of farming is perhaps the most important cultural change in the history of modern humans. Increased food production led to the development of societies that stayed put, rather than wandering in search of food. The resulting population growth culminated in the seven billion people who now live on the planet. In Europe, farming spread from the 'Fertile Crescent', a region extending from the eastern Mediterranean coast to the Persian Gulf and including the Tigris and Euphrates valleys.

There has been much debate about whether the westerly spread of agriculture from the Near East was driven by farmers actually migrating, or by the transfer of ideas and technologies to indigenous hunter-gatherers. Now, researchers have studied the genetic diversity of modern populations to throw light on the processes involved in these ancient events.
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A Predominantly Neolithic Origin for European Paternal Lineages

Patricia Balaresque1, Georgina R. Bowden1, Susan M. Adams1, Ho-Yee Leung1, Turi E. King1, Zoë H. Rosser1,Jane Goodwin2, Jean-Paul Moisan3, Christelle Richard3, Ann Millward4, Andrew G. Demaine4, Guido Barbujani5, Carlo Previderè6, Ian J. Wilson7, Chris Tyler-Smith8, Mark A. Jobling1*

1 Department of Genetics, University of Leicester, Leicester, United Kingdom,2 Ty Celyn, Maeshafod, Blaina, Gwent, United Kingdom, 3 Laboratoire d'Etude du Polymorphisme de l'ADN, Faculté de Médecine, Nantes, France, 4Molecular Medicine Research Group, Peninsula Medical School, Universities of Exeter and Plymouth, Plymouth, United Kingdom, 5 Dipartimento di Biologia ed Evoluzione, Università di Ferrara, Ferrara, Italy, 6 Dipartimento di Medicina Legale e Sanità Pubblica, Università di Pavia, Pavia, Italy, 7 Institute of Human Genetics, Newcastle University, Newcastle upon Tyne, United Kingdom, 8 The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, United Kingdom

Abstract

The relative contributions to modern European populations of Paleolithic hunter-gatherers and Neolithic farmers from the Near East have been intensely debated. Haplogroup R1b1b2 (R-M269) is the commonest European Y-chromosomal lineage, increasing in frequency from east to west, and carried by 110 million European men. Previous studies suggested a Paleolithic origin, but here we show that the geographical distribution of its microsatellite diversity is best explained by spread from a single source in the Near East via Anatolia during the Neolithic. Taken with evidence on the origins of other haplogroups, this indicates that most European Y chromosomes originate in the Neolithic expansion. This reinterpretation makes Europe a prime example of how technological and cultural change is linked with the expansion of a Y-chromosomal lineage, and the contrast of this pattern with that shown by maternally inherited mitochondrial DNA suggests a unique role for males in the transition.

Author Summary

Arguably the most important cultural transition in the history of modern humans was the development of farming, since it heralded the population growth that culminated in our current massive population size. The genetic diversity of modern populations retains the traces of such past events, and can therefore be studied to illuminate the demographic processes involved in past events. Much debate has focused on the origins of agriculture in Europe some 10,000 years ago, and in particular whether its westerly spread from the Near East was driven by farmers themselves migrating, or by the transmission of ideas and technologies to indigenous hunter-gatherers. This study examines the diversity of the paternally inherited Y chromosome, focusing on the commonest lineage in Europe. The distribution of this lineage, the diversity within it, and estimates of its age all suggest that it spread with farming from the Near East. Taken with evidence on the origins of other lineages, this indicates that most European Y chromosomes descend from Near Eastern farmers. In contrast, most maternal lineages descend from hunter-gatherers, suggesting a reproductive advantage for farming males over indigenous hunter-gatherer males during the cultural transition from hunting-gathering to farming.

Citation: Balaresque P, Bowden GR, Adams SM, Leung H-Y, King TE, et al. (2010) A Predominantly Neolithic Origin for European Paternal Lineages. PLoS Biol 8(1): e1000285. doi:10.1371/journal.pbio.1000285

Academic Editor: David Penny, Massey University, New Zealand

Received: May 8, 2009; Accepted: December 10, 2009; Published: January 19, 2010

Copyright: © 2010 Balaresque 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: MAJ was supported by a Wellcome Trust Senior Fellowship in Basic Biomedical Science (grant number 057559); PB, GRB, SMA, ZHR, and CTS were supported by the Wellcome Trust (www.wellcome.ac.uk). 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.

Abbreviations: hg, haplogroup; KYA, thousand years ago; mtDNA, mitochondrial DNA; TMRCA, time to the most recent common ancestor

* E-mail: maj4@le.ac.uk

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