Dating encounters between modern humans and Neandertals

October 04, 2012

To discover why Neandertals are most closely related to people outside Africa, Harvard and Max Planck Institute scientists have estimated the date when Neandertals and modern Europeans last shared ancestors. The research, published in the journal PLOS Genetics, provides a historical context for the interbreeding. It suggests that it occurred when modern humans carrying Upper Paleolithic technologies encountered Neandertals as they expanded out of Africa.

When the Neandertal genome was sequenced in 2010 it revealed that people outside Africa share slightly more genetic variants with Neandertals than Africans do. One scenario that could explain this observation is that modern humans mixed with Neandertals when they came out of Africa. An alternative, but more complex, scenario is that African populations ancestral to both Neandertals and modern humans remained subdivided over a few hundred thousand years and that those more related to Neandertals subsequently left Africa.

Dr. Sriram Sankararaman and colleagues measured the length of DNA pieces in the genomes of Europeans that are similar to Neandertals. Since recombination between chromosomes when egg and sperm cells are formed reduces the size of such pieces in each generation, the Neandertal-related pieces will be smaller the longer they have spent in the genomes of present-day people.

The team estimate that Neandertals and modern humans last exchanged genes between 37,000 and 86,000 years ago, well after modern humans appeared outside Africa but potentially before they started spreading across Eurasia. This suggests that Neandertals (or their close relatives) had children with the direct ancestors of present-day people outside Africa.
-end-
FINANCIAL DISCLOSURE: This work was supported by the Presidential Innovation Fund of the Max Planck Society, the Krekeler Foundation, and the National Science Foundation (HOMINID grant 1032255). 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.

CITATION: Sankararaman S, Patterson N, Li H, Pääbo S, Reich D (2012) The Date of Interbreeding between Neandertals and Modern Humans. PLoS Genet 8(10):e1002947. doi:10.1371/journal.pgen.1002947

PLEASE ADD THIS LINK TO THE FREELY AVAILABLE ARTICLE IN ONLINE VERSIONS OF YOUR REPORT (the link will go live when the embargo ends): http://www.plosgenetics.org/doi/pgen.10029347

CONTACT:

Dr. Sriram Sankararaman
Harvard Medical School
Dept of Genetics
77, Avenue Louis Pasteur
NRB 260
Boston, MA 02115
UNITED STATES
sankararaman@genetics.med.harvard.edu

Disclaimer

This press release refers to an upcoming article in PLOS Genetics. The release is provided by journal staff, or by the article authors and/or their institutions. Any opinions expressed in this release or article are the personal views of the journal staff and/or article contributors, and do not necessarily represent the views or policies of PLOS. PLOS expressly disclaims any and all warranties and liability in connection with the information found in the releases and articles and your use of such information. About PLOS Genetics

PLOS Genetics reflects the full breadth and interdisciplinary nature of genetics and genomics research by publishing outstanding original contributions in all areas of biology. All works published in PLOS Genetics are open access. Everything is immediately and freely available online throughout the world subject only to the condition that the original authorship and source are properly attributed. Copyright is retained by the authors. The Public Library of Science uses the Creative Commons Attribution License.

About the Public Library of Science

The Public Library of Science (PLOS) is a non-profit organization of scientists and physicians committed to making the world's scientific and medical literature a freely available public resource. For more information, visit http://www.plos.org. 2pm Pacific/5pm Eastern Time/10pm GMT Everything published by PLOS Genetics is open access, allowing anyone to download, reuse, reprint, modify, distribute, and/or copy articles, so long as the original authors and source are cited. Please mention PLOS Genetics in your report and use the link(s) below to take readers straight to the online articles. Thank you.

PLOS

Related Modern Humans Articles from Brightsurf:

Paleogenomics -- the prehistory of modern dogs
An international team of scientists has used ancient DNA samples to elucidate the population history of dogs.

Modern humans took detours on their way to Europe
Climate conditions shaped the geography of settlement by Homo sapiens in the Levant 43,000 years ago / findings of Collaborative Research Centre 806 'Our Way to Europe' published in 'PLOS ONE'

Studying the Neandertal DNA found in modern humans using stem cells and organoids
Protocols that allow the transformation of human induced pluripotent stem cell (iPSC) lines into organoids have changed the way scientists can study developmental processes and enable them to decipher the interplay between genes and tissue formation, particularly for organs where primary tissue is not available.

ADHD: genomic analysis in samples of Neanderthals and modern humans
The frequency of genetic variants associated with attention-deficit/hyperactivity disorder (ADHD) has decreased progressively in the evolutionary human lineage from the Palaeolithic to nowadays, according to a study published in the journal Scientific Reports.

Modern humans, Neanderthals share a tangled genetic history, study affirms
A new study reinforces the concept that Neanderthal DNA has been woven into the modern human genome on multiple occasions as our ancestors met Neanderthals time and again in different parts of the world.

Europe's Neanderthals relied on the sea as much as early modern humans
The first significant evidence of marine resource use among Europe's Neanderthals is detailed in a new report, demonstrating a level of marine adaptation previously only seen in their contemporary modern humans living in southern Africa.

Infectious disease defenses among ancient hominid contributions to adaptation of modern humans
In a new study published in the advanced online edition of Molecular Biology and Evolution, scientists Alexandre Gouy and Laurent Excoffier have developed new computational tools to better analyze human genome datasets, and found more evidence of a legacy of ancient hominid adaptation, particularly to help fight off infectious diseases like malaria.

Early modern humans cooked starchy food in South Africa, 170,000 years ago
The inhabitants of the Border Cave in the Lebombo Mountains on the Kwazulu-Natal/eSwatini border were cooking starchy plants 170,000 years ago.

Researchers determine age for last known settlement by a direct ancestor to modern humans
An international team of researchers has determined the age of the last known settlement of the species Homo erectus, one of modern humans' direct ancestors.

The homeland of modern humans
A landmark study pinpoints the birthplace of modern humans in southern Africa and suggests how past climate shifts drove their first migration.

Read More: Modern Humans News and Modern Humans Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.