Humans Part Neanderthal: DNA Evidence from X Study
Author: University of Montreal
Published: 2012/02/28 - Updated: 2026/02/07
Publication Details: Peer-Reviewed, Research, Study, Analysis
Category Topic: Offbeat News - Related Publications
Page Content: Synopsis - Introduction - Main - Insights, Updates
Synopsis: This peer-reviewed research from the University of Montreal, published in Molecular Biology and Evolution, provides genetic evidence that modern humans outside Africa carry Neanderthal DNA sequences on their X chromosomes. Led by Dr. Damian Labuda, the team analyzed 6,000 chromosomes from populations worldwide and found a specific haplotype present in all non-African groups but absent in sub-Saharan Africa, confirming interbreeding occurred around 50,000 to 80,000 years ago, likely in the Middle East. The findings matter because they help us understand human evolution and genetic diversity, showing how inherited traits from extinct human relatives may have contributed to our species' adaptability and survival across different environments - information relevant to anyone interested in human biology, ancestry, and the genetic factors that influence health conditions across diverse populations today - Disabled World (DW).
- Definition: Neandertal
Neandertals, Homo neanderthalensis or Homo sapiens neanderthalensis, is an extinct species of archaic humans living in Eurasia until about 40,000 years ago. While the "causes of Neanderthal disappearance about 40,000 years ago remain highly contested," demographic factors like small population size, inbreeding, and random fluctuations are considered likely factors. Other scholars have proposed competitive replacement, assimilation into the modern human genome (bred into extinction), significant climatic change, disease, or a combination of these factors.
What is the difference between Neanderthal and Neandertal? A few scientific publications prefer Neandertal. Neanderthal, the original spelling, was derived from the German valley where Neanderthal fossils were first discovered in the 19th century. In 1901, however, the German name of the valley was officially changed to Neandertal.
Introduction
Research Confirms Humans Are Part Neanderthal
Some human X chromosome originates from Neanderthals and is found exclusively in people outside Africa, according to an international team of researchers led by Damian Labuda of the Department of Pediatrics at the University of Montreal and the CHU Sainte-Justine Research Center. The research was published in the July issue of Molecular Biology and Evolution.
"This confirms recent findings suggesting that the two populations interbred," says Dr. Labuda. His team places the timing of such intimate contacts and family ties early on, probably at the crossroads of the Middle East.
Main Content
Neanderthals, whose ancestors left Africa about 400,000 to 800,000 years ago, evolved in what is now mainly France, Spain, Germany, and Russia and are thought to have lived until about 30,000 years ago. Meanwhile, early modern humans left Africa about 80,000 to 50,000 years ago. The question on everyone's mind has always been whether the physically stronger Neanderthals, who possessed the gene for language and may have played the flute, were a separate species or could have interbred with modern humans. The answer is yes, the two lived in close association.
"In addition, because our methods were independent of Neanderthal material, we can also conclude that previous results were not influenced by contaminating artifacts," adds Dr. Labuda.
Dr. Labuda and his team, almost a decade ago, had identified a piece of DNA (called a haplotype) in the human X chromosome that seemed different and whose origins they questioned. When the Neanderthal genome was sequenced in 2010, they quickly compared 6000 chromosomes from all parts of the world to the Neanderthal haplotype. The Neanderthal sequence was present in peoples across all continents, except for sub-Saharan Africa, including Australia.
"There is little doubt that this haplotype is present because of mating with our ancestors and Neanderthals. This is a very nice result, and further analysis may help determine more details," says Dr. Nick Patterson, of the Broad Institute of MIT and Harvard University, a major researcher in human ancestry who was not involved in this study.
"Dr. Labuda and his colleagues were the first to identify a genetic variation in non-Africans that was likely to have come from an archaic population. This was done entirely without the Neanderthal genome sequence. Still, in light of the Neanderthal sequence, it is now clear that they were right!" adds Dr. David Reich, a Harvard Medical School geneticist, one of the principal researchers in the Neanderthal genome project.
So, speculates Dr. Labuda, did these exchanges contribute to our global success?
"Variability is significant for long-term survival of a species," says Dr. Labuda. "Every addition to the genome can be enriching." An interesting match, indeed.
"An X-linked haplotype of the Neanderthal origin is present among all non-African populations" was published in the July 2011 issue of Molecular Biology and Evolution. The authors are Vania Yotova, Jean-Francois Lefebvre, Claudia Moreau, Elias Gbeha, Kristine Hovhannesyan, Stephane Bourgeois, Sandra Bedarida, Luisa Azevedo, Antonio Amorim, Tamara Sarkisian, Patrice Hodonou Avogbe, Nicodeme Chabi, Mamoudou Hama Dicko, Emile Sabiba Kou' Santa Amouzou, Ambaliou Sanni, June Roberts-Thomson, Barry Boettcher, Rodney J. Scott, and Damian Labuda. The study was supported by grants from the Canadian Institutes of Health Research.
Insights, Analysis, and Developments
Editorial Note: The confirmation that most of humanity carries Neanderthal genetic material fundamentally changes how we understand ourselves as a species. Rather than being a single, isolated evolutionary branch, modern humans are actually a genetic blend - a mosaic of different ancient populations that met, mixed, and contributed to what we are today. This research raises intriguing questions about which specific traits or disease susceptibilities we may have inherited from our Neanderthal ancestors, and whether this ancient genetic exchange provided advantages that helped early humans colonize diverse environments from Europe to Australia. As genetic sequencing becomes more sophisticated, we'll likely uncover even more about these ghost ancestors whose DNA still shapes human health and variation across the globe - Disabled World (DW).Attribution/Source(s): This peer reviewed publication was selected for publishing by the editors of Disabled World (DW) due to its relevance to the disability community. Originally authored by University of Montreal and published on 2012/02/28, this content may have been edited for style, clarity, or brevity.