National Geographic News
A photo of a reconstruction of a Neanderthal female.

Modern people of Eurasian descent owe about 2 percent of their genes to ancient mating with Neanderthals.

PHOTOGRAPH BY JOE MCNALLY, NATIONAL GEOGRAPHIC

Dan Vergano

National Geographic

Published April 22, 2014

Modern humanity's ancient cousins, the Neanderthals, lived in small groups that were isolated from one another, suggests an investigation into their DNA. The analysis also finds that Neanderthals lacked some human genes that are linked to our behavior. (Related: "Why Am I Neanderthal?")

In recent years, experts in ancient DNA have mapped out the genes of Neanderthals, a species of human that vanished some 30,000 years ago. These gene maps have revealed that many modern people share a small part of their ancestry, and a small percentage of their genes, with those early humans.

Now moving beyond ancestry, researchers are comparing these ancient gene maps to those of modern humans. The comparisons may point to genes that make us uniquely human and uncover links to the origins of genetic ailments.

Compared to Neanderthals, humanity appears to have evolved more when it comes to genes related to behavior, suggests a team headed by Svante Pääbo, a pioneer in ancient genetics at Germany's Max Planck Institute for Evolutionary Anthropology. Their study was published today in the Proceedings of the National Academy of Sciences.

They note in particular that genes linked to hyperactivity and aggressive behavior in modern humans appear to be absent in Neanderthals. Also missing is DNA associated with syndromes such as autism.

"The paper describes some very interesting evolutionary dynamics," said paleoanthropologist John Hawks of the University of Wisconsin at Madison.

The Neanderthal genes suggest that sometime after one million to 500,000 years ago, Neanderthal numbers decreased and the population stayed small, Pääbo's group determined. A small population size would have been bad news for Neanderthals, Hawks said, because it would have meant that "natural selection had less power to weed out bad mutations."

Ancient Answers

Pääbo and colleagues looked at the genes of two ancient Neanderthals, one from Spain and one from Croatia. They compared the DNA of those individuals to that of a third Neanderthal who had lived in Siberia and whose DNA had been analyzed in an earlier study, and to the DNA of several modern humans.

"We find that [Neanderthals] had even less [genetic] variation than present-day humans," Pääbo said by email. Genetic diversity among Neanderthals was about one-fourth as much as is seen among modern Africans, he said, and one-third that of modern Europeans or Asians.

The comparison also showed that modern people possess genes linked to heart health and metabolism that were absent in our ancient cousins. We also have genes for skin and hair color they lacked. "These mutations may contribute to differences in pigmentation among present-day humans," Pääbo and colleagues wrote in the PNAS study.

Hawks cautioned, however, that comparing ancient humans to modern ones is a bit misleading, "because humans today have a recent history of massive population growth."

That recent population growth obscures the signal of gene differences that are part of our ancient heritage, when people lived lives more like the Neanderthals', and ones that sprang up only since the advent of farming.

If scientists want to know what really separates Neanderthals from Homo sapiens, "we need to figure out how much of today's pattern comes from ancient hunter-gatherers, and how much comes from our recent adaptation," he said.

The Pääbo team also compared the Neanderthal and modern human DNA to that of a Denisovan, another early human cousin species that lived in Siberia as recently as 40,000 years ago and is known only from genetic maps and a few scraps of bones.

The main genetic difference found in that comparison relates to the curvature of the lower back, according to the study. Essentially, Neanderthals looked a bit less sway-backed than do modern humans, Denisovans, and our other early ancestors.

A series of photos of a reconstruction of a Neanderthal woman.
Neanderthals and modern humans have differences in genes linked to aggression.
PHOTOGRAPHS BY JOE MCNALLY, NATIONAL GEOGRAPHIC

Ancient Questions

Humans, Neanderthals, and Denisovans shared a common ancestor more than half a million years ago. That connection, however, has been muddied by more recent interbreeding that likely took place among our ancient ancestors after early modern humans migrated out of Africa about 60,000 years ago.

Modern people of Eurasian descent owe about 2 percent of their genes to ancient mating with Neanderthals, and people of Melanesian descent owe perhaps 3 to 5 percent of their genes to Denisovans for the same reason. (Related: "Surprise! 20 Percent of Neanderthal Genome Lives On.")

But the story doesn't end with the mere presence of genes or mutations within them. The PNAS study found, for instance, genetic differences between Neanderthals and modern humans in genes linked to aggression. But the authors caution that "if [the genes] affected activity or aggression levels, it is unclear whether they increased or decreased such traits." They cannot say, for now, which species would have been the more aggressive one.

And there's also the question of how often any genes present were actually used, called gene activity. In a recent study published in the journal Science, Israeli researchers teamed up with Pääbo's group to look at gene activity in Neanderthals who lived 50,000 or more years ago. (Reas "The Case of the Missing Ancestor" in National Geographic magazine.)

That study showed how differences in the expression of genes shared by modern people and our ancient cousins led to Neanderthals possessing bigger hands, shorter arms, and a more burly build.

"The conclusions regarding skeletal change being greater along the Neanderthal lineage than the modern human one appear to be at odds with the usual view of Homo sapiens," said human origins expert Chris Stringer of the Natural History Museum in London. Compared to the robust-looking earlier human species that preceded Neanderthals, humans appear more changed by evolution, with lighter skulls and thinner bones.

Pääbo cautioned, however, against equating genetic change with evolutionary sophistication. "Clearly, Neandertals were not 'less evolved' than modern humans," he said. "They had their own history and evolution. They took another path, if you like."

Follow Dan Vergano on Twitter.

48 comments
Vincenzo Leopoldo Cassibba
Vincenzo Leopoldo Cassibba

All human populations had and have different behaviours and interpretations of the reality, as far as ethics, religion, etc. are concerned , which can not be considered less or more evolved. But these differences often had been and continue to be at the basis of strong contrasts - and even conflicts - among the human populations. I think that the prevailing cause of the extinction of Neanderthals must be found in some kind of behavioural  conflict with the so called Homo sapiens. The climate could not decisively influence   the extinction. And the same can be affirmed about the material culture,  not so different if we consider the first late palaeolithic industries. In my opinion, the physical and knowledge confrontation was at the basis of these conflicts. May be that we can never reconstruct these differences, inevitably lost, unless we want to simply conclude that the first cause was the racism, the most unfortunate fault of humanity. 



Joyce Willis
Joyce Willis

The fact that Neanderthals were less aggressive says a lot about how they might have gone extinct...

Allison Britt
Allison Britt

So, how much genetic difference between pre interbreeding with Neanderthals and post interbreeding with Neanderthals would there have to be before Homo Sapiens after that event would be considered a different or sub species.  If the two populations are considered different, wouldn't their offspring have been a different group as well?  Is there a specific number of genes you have to get to before a sub group would be identified? 

Tom Carberry
Tom Carberry

"We find that [Neanderthals] had even less [genetic] variation than present-day humans," Pääbo said by email.


Although this article doesn't state it explicitly, in other articles John Hawks has discussed that when geneticists say such things, they mean they have discovered evidenced of inbreeding, or incest, because of small population size.


Denisovans also show this sort of inbreeding, as do humans in studies going back farther, which some geneticists call a human bottleneck, where the race almost died out.


I believe that eventually we will learn that Neanderthals and Denisovans form the genetic mutations of the off spring of the human bottleneck.  In other words, inbreeding leads to mutations, and something terrible happened to wipe out most humans and we and other mutations occurred.



Pepe Avila
Pepe Avila

interesante el articulo sobre la evolucion del hombre

Anne Leinenga
Anne Leinenga

These fact s  don't surprise me  because homo sapiens differs only 3 percent from the Orangutan   So the fact that Eurasians have 2 percent Neanderthal DNA

Clearly the Neanderthal did not become extinct  but evolved to /with modern man it s called evolution and some human behavior.


Andrew Hardy
Andrew Hardy

The more I read about Neanderthals, the more I'm convinced that they were the pre-flood people in the Bible. The Bible Genesis account reveals some things about human life back then. First of all, everybody lived several hundred years and men were often over 100 years old before engaging in pro-creation. The sex-drive and/or nearly uncontrollable sexual lust of modern man was apparently absent. Modern research indicates seeming co-existence without significant interbreeding between modern humans and Neanderthals. The Global Deluge (Noah's flood) would explain that. The removal of a water canopy would've had major climactic effects. Archaeological finds suggest that severe climactic change occurred around the time of extinction of Neanderthals, as well as severely reduced pollen levels, which would be expected after a Global deluge. As post-flood humans spread back out, they would've to some extent ended up living in the same places as pre-flood Neanderthals within a short time, so it may appear as co-existence. Also, according to the Bible, you have Noah & his wife and his 3 sons and their wives who are still Neanderthal and continue to live 500 years or more after the flood, but their offspring experience considerable shortening of lifespan with each successive generation. There may have been significant genetic change at work here. It's interesting that Neanderthals appear to have lived in small Nuclear Family dwellings at some distance from others. This would be commensurate with a people who were closer to Godly perfection as the Bible suggests. In the Bible, God instructed the early offspring of Noah's family to spread out over the Earth but they rebelled and built the Tower of Babel. The Bible also says that some Angels took an interest in human females and came down to the Earth, materialized into men and took human women as wives for themselves "namely all whom they chose." This could've had an impact on Neanderthal population if children were born infrequently. Also, according to the Bible, False Religion was born at Babel which suggests that prior to the flood, it had never occurred to anyone that they should take invent a lie or set of lies to explain their existence and invent phony gods to give worship to, so you'd expect to not find religious artifacts/idols in any purely Neanderthal deposits.

Donald McMiken
Donald McMiken

Genetic technology has gotten us to a point where we can make comparisons of modern humans with out archaic and now extinct cousins, Neanderthals and Denisovans. The past really is a foreign country and they did do things differently there. 

V. Taylor
V. Taylor

Curse of Ham ! and Seth  and Japheth sons of Noah!


Who were the Negroid? 

Andrew Hardy
Andrew Hardy

We keep making progress which is exciting, BUT,  I doubt I'm the only person who now sees and has spent his/her entire life seeing a huge invisible banner hanging over all this which asks "So when are you gonna start fixing us?" 


We suck! We know we SUCK! We start aging in our twenties. Our teeth wear out, decay and don't renew. Our skins wrinkles. Our hair turns gray and/or stops growing. WE AGE and that SUCKS!


Of course, this doesn't even take into account the various maladies, birth defects and diseases from which we suffer, but if we could fix our genome, maybe we wouldn't have to worry about that stuff. Maybe aging isn't something that can be prevented just by having a perfect genome Things are so bloody complex. It seems we've spent the last 50 years just getting a grasp of how complex it all is and maybe we're nearing the end of discovering new layers of complexity and can start sorting out how it all works. Yay for computers!

Andrew Hardy
Andrew Hardy

Neanderthals were "a bit less sway-backed"? In other words they had better posture? Well now that wasn't what we were supposed to discover was it?


By the sound of things, they were bigger and better and less susceptible to brain disorders and health problems. Probably lived for almost a thousand years. Probably the people that the Bible says lived before the Great Deluge.


The Denisovans were probably the Nephilim also spoken of in the Bible - the children of sexual unions between materialized Angels (the "Fallen Angels") and "Neanderthal" human women who were unusually large in size.

Bistecca Mammuth
Bistecca Mammuth

Really interesting paper. Da leggere. Massimo Pandolfi in Bistecca Mammuth.

Edward Boss
Edward Boss

Apparently the Devonian, neanderthals and pre humans had all mated with one another at one time or the other and it appears the modern human genetics were more adapt at surviving and the others were either breed out or became extinct.  And yes to  Anthony Olivera on committing about the dancing neanderthal woman's Chi Chi's while showing no aggression.  All kids first experience with female breast were in the old National Geographic 

in schools in the USA. in the 50 fifties.   

Mark Eastaugh
Mark Eastaugh

It all makes a lot of sense to me .... modern humans very likely survived hard times (volcanic eruptions, ice ages) because they could co-operate, not just within groups, but between groups. (Give or take a few world wars!) 

Perhaps neanderthals lived in small isolated family groups because they were more territorial (as most animals are) and fought or avoided strangers on contact ...... whereas the first instinct of modern man may have been to negotiate.... I suspect 'territorial-ism' (new word?) may be more a product of organized structured societies (kings and armies) rather than a natural human instinct.

Susan S.
Susan S.

WHERE ARE THEY GETTING THIS FROM? The same place as Global Warming?

Should had acquired a college degree in bioscience, bioengineering, or climatologist. Then go to lands where the government suckers are - propose some "touchy/feely" science project to answer questions that still cannot be answered, control stuff we can't control - nature/weather - then suppress religion for our scientific religion. Living a wonderful life, with lots of grant money and not doing a thing. Set up experiments and have your underlings do all the work. Then lie about the results, to continue getting the grant money and if caught, say there was a mistake in the study - blaming an underling who "didn't follow your directions". Sheesh. What a gig. 

George Lyon
George Lyon

Just read a recent novel (Ancestor by Raymond Steyn) where the author is critical of scientists drawing so much conclusions from DNA differences when we're not even sure what role they play. Perhaps (as in the novel) we should clone one, so we can better explore these differences...(Prof Church from Harvard has suggested this is a real possibility)

Yanna Gounari
Yanna Gounari

I'm a bit pazzled. The only definition of separate species I know refers to the inability of producing fertile offsprings. If 2% of our genes reflect that Homo Sapiens mated with Homo Neanderthalensis, how can they be considered separate species?

Bistecca Mammuth
Bistecca Mammuth

Interesting. Even genetical analysis confirm, more than show, that neanderthals lived in small quite closed groups, as many social predators do till now. ^_^ . Massimo Pandolfi

Marcos Toledo
Marcos Toledo

I hope this article puts and a end to the Neanderthals as brutes theory. As to how much Neanderthal genes survive in the modern gene pool we must wait as to when the paleontologist own up to the truth some time in the future.

Sharalyn Pliler
Sharalyn Pliler

I had my DNA analyzed at 23andme.com, and discovered that II have 3 percent Neanderthal DNA. I don't know what it means, but it's fun to know, and I can say I've been there, done that, and I got the T-shirt. (There really are T-shirts that brag about how much of Neandy DNA you have.)

Daniel Thompson
Daniel Thompson

Humans migrated out of Africa we're told.  Where did the Neanderthals originate and how did they end up in Europe, etc.? 

Kenneth Gardner
Kenneth Gardner

Researchers believe that they became compulsively obsessed with killing beings more intelligent than themselves, and began using words such as "Benghazi" and "Obummer" in rituals including colored water and baked goods.

Ron Bockman
Ron Bockman

Here, in Philadelphia, the Neanderthals live just like everyone else

Liz Davidson Machado
Liz Davidson Machado

@Andrew Hardy

Andrew, There is an abundance of scientific evidence that Neanderthals rarely lived past 40 years. Also, Neanderthals and modern humans existence overlapped for thousands of years. Although there is an abundance of geological evidence suggesting large floods happening in localized areas, there is no evidence for a worldwide deluge. If you lived in the Middle East in the days of the Bible a large flood would be your whole world.  Finally, the earliest evidence for religion and idol worship, approximately 30,000 years ago, is way earlier than any known civilization (Tower of Babel). Female idols found all over Europe clearly suggests people were worshiping "false" gods before a Christian god. Although the bible provides an abundance of historical information, not all of it should be taken literally. It is clear from you comments that you have thought a lot about this and that is great......     

Philip Olson
Philip Olson

@Andrew Hardy

The Neanderthals had a shorter lifespan.  One of the major factors in modern human survival was the mutation for a longer life.  This allowed more accumulated knowledge available to be passed on, resulting in better usage of resources during the periods of rapid change.

The older folks had a 'been there done that' when the climate was seesawing back and forth.  Experience counts.


Any information the religious texts may have is absolutely post agriculture, which was 20,000 years after the last Neanderthal or Denisovan went extinct.

Susan S.
Susan S.

@Andrew Hardy  , interesting reply. Regarding Neanderthal, these ancients appear to be smaller/shorter than their earlier ancestors as we also are. We currently label both their and our ancestors as "Early Homo Sapens".



Fausto Montoya
Fausto Montoya

@Mark Eastaugh  Can it be that  Devonian  and any other pre human species were more territorial and aggressive  and kept the neanderthal  more isolated and afraid of  being put down as it happened ? Why do I fail to believe the smarter clans were not into trading ?I can  relate sort of with territorialism  "your new word "being more of a  keep out warning instead of a welcome ! Now ! organizing societies  within the same tribe will in fact promote negotiations  ! Was the word Raid in use during those times ? Yes i am sure ! negotiations  do not happen during a raid ! Then nor now !  Smarts  need to be accompanied  by good will to work properly ! Good Day !

jill greer
jill greer

@Susan Sona What kind of exposure to real university research have you ever had?  That's equivalent to negating all religion because there are fanatical terrorists and there was a terrible thing called the Inquisition.  Science is a system of acquiring knowledge that can be empirically verified.  Faith by definition is  belief in something that cannot be touched or seen, therefore the two deal with completely separate aspects of existence.  There's nothing 'touchy/feely' about global warming -  satellite pics show the polar ice caps shrinking,  spring is coming sooner in temperate zones,  some Pacific Islands are already below sea level because of the melting of those ice caps (and what few glaciers still exist).  Key life forms like small amphibians are shifting habitat or dying off due to the temperature changes.  Those who prefer a fictional conspiracy among scientists are the ones in 'touchy/feely' land,  delusional and scientifically illiterate, so they turn to a sacred book that they cannot even read in the original languages or put into a historical context.  Sheesh -  what a sad self-deception!



Bridget Cameron
Bridget Cameron

I don't think Neanderthals are a different species, they're just another race. The fact that they make up part of Eurasian genetic code states quite clearly that they are part of all people of European and Asian descent, just as the Denisovians are part of Melanesian and aboriginal peoples! It's about high time that Science got its facts right and changed the history books!   @Yanna Gounari

Madison Maitland
Madison Maitland

@Yanna Gounari  In light of new genetic evidence (I believe), researchers think neandertals may have been a sub-species of humans -- Homo sapiens neanderthalensis -- similar to the case with the 4 subspecies of Chimpanzees. It's still being debated, as far as I know, and probably will be for a long time. You'll see them named differently depending on what you read and what those researchers believe.

gina leonard
gina leonard

@Yanna Gounari early ancestors may have been able to mate but over the course of thousands of years they probably evolved differently? That is sort of what I gathered from this. Also, Neanderthals were a species of human.

John Warner
John Warner

@Sharalyn Pliler Greetings, Cousin. I have 2.9% Neanderthal DNA, and between 8 and 10% Native American DNA.  I have also seem some posts where correlations between high IQ and Neanderthal DNA have been made...mine's about 150ish (Triple Nine Society member).  Wonder if it's true?

Danny Muller
Danny Muller

@Daniel Thompson "Modern humans" migrated out of Africa to replace all existing archaic humans (like Neanderthals) that had already spread and settled across the globe. Those same "modern humans" and Neanderthals have common ancestors going even further back than archaic humans.

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