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M. Hofreiter / K. Fiusterweier
Researchers say some Neanderthals may have had pale skin and red hair similar to that of some modern humans. Explaining the genetic similarities, however, can lead to a tangled tale.
One of the most titillating tales in the study of human origins — focusing on whether Neanderthals interbred with modern humans — has just gotten more tangled.
Over the past couple of years, studies of Neanderthal DNA samples painstakingly extracted from ancient bones have suggested that contemporary non-Africans can trace up to 4 percent of their genetic code to our long-extinct Neanderthal cousins. The genomes of modern-day Africans, in contrast, have virtually nothing in common with the Neanderthals. Researchers assumed that the genetic contribution for the non-Africans was passed down through cross-species sex during the time that Neanderthals and Homo sapiens lived in close proximity in Europe, tens of thousands of years ago.
However, there's another possibility: Maybe that common genetic code was passed down from the common ancestor of Homo sapiens and Homo neanderthalensis, hundreds of thousands of years ago in Africa. Today, researchers at the University of Cambridge reported in the Proceedings of the National Academy of Sciences that such a scenario provides a better fit for the genetic data. They say there's no need to assume that anatomically modern humans did the Neanderthal nasty, a process known more scientifically as hybridization.
"Our work shows clearly that the patterns currently seen in the Neanderthal genome are not exceptional, and are in line with our expectations of what we would see without hybridization," the lead researcher, Andrea Manica, said in a Cambridge news release. "So, if any hybridization happened — it's difficult to conclusively prove it never happened — then it would have been minimal and much less than what people are claiming now."
Modeling population dynamics
Manica and his colleagues set up a computer model for the last half-million years of population dynamics, with the assumption that there were two migrations from Africa. The first migration led to the settlement of Europe by the ancestors of the Neanderthals, hundreds of thousands of years ago. Then, around 300,000 to 350,000 years ago, the route from north Africa to Europe was cut off somehow. The European and north African populations showed gradual genetic divergence, but still retained a bit of common heritage from their mutual ancestors.
When the second migration from Africa took place, around 60,000 to 70,000 years ago, the north Africans who dispersed to Europe and Asia would carry that extra bit of genetic similarity with them. But the Africans who lived farther south and stayed behind on the continent wouldn't have as much genetic kinship with the Europeans.
The researchers found that their model did a fine job of accounting for the existing data without Neanderthal sex.
So what do the researchers behind the earlier DNA studies say? That's where it gets really interesting: One study, published online in April in Molecular Biology and Evolution, contends that ancient population dynamics alone can't account for the genetic patterns seen in the DNA from Neanderthals and modern humans. Another study, posted on the arXiv preprint server and due for publication in PLOS Genetics, takes a closer look at a genetic pattern known as linkage disequilibrium — and concludes that modern humans and Neanderthals interbred somewhere between 37,000 and 86,000 years ago. Nature's Ewen Callaway delves into the details surrounding those claims and counterclaims.
Either-or proposition?
So, to recap: Some scientists say the population dynamics that were in effect hundreds of thousands of years ago can explain genetic similarities between populations, even if those populations never interbred. Others say the evidence is getting stronger that modern humans and Neanderthals really did mate when they met up in Europe, tens of thousands of years ago.
University of Washington geneticist Joshua Akey says both sides just might be right.
"To me, I don't think it's a case of either-or," he told me. "I think that both things can be going on."
Akey and other researchers recently published a study in the journal Cell suggesting that a mysterious "Neanderthal sibling species" made a genetic contribution to the DNA of modern-day Africans. He said that interpreting whether genetic similarities come from a common ancestor (a process known as archaic population structure) or from more recent cross-species sex (a process that Akey calls introgression) is a tricky but essential task for those who study human origins.
"Ultimately, it's important that we come to a consensus as to one process or the other, but I find them both to be interesting interpretations," Akey said. "Introgression is a sexier mechanism, but even if it turns out to be a case of archaic population structure, that still tells us something about our past that we didn't know before."
So did modern humans do it with Neanderthals or not? And to what extent? Today, maybe it's a tangled tale, but that won't necessarily be the case forever. Akey said he was optimistic that researchers will be able to "tease apart" the different influences from the two processes within the next year or so.
Update for 2:10 a.m. ET Aug. 14: In a follow-up email, Akey clarified his view on the "did they do it" question, leaning toward the affirmative:
"Although I do think that both ancestral population structure and introgression are not mutually exclusive events, the recent papers from David Reich and Monty Slatkin show pretty compelling evidence that introgression of Neanderthal lineages into anatomically modern humans occurred. Thus, the real debate moving forward will be about the relative contributions of these two processes."
More about ancient hominid sex:
- Neanderthal-human sex rarely produced kids
- Ancestors had sex with mysterious human cousins
- How sex with Neanderthals made us stronger
Cambridge's Anders Eriksson is Manica's co-author on the paper published by the Proceedings of the National Academy of Sciences, titled "Effect of Ancient Population Structure on the Degree of Polymorphism Shared Between Modern Human Populations and Ancient Hominins."
Authors of the study in Molecular Biology and Evolution are Melinda Yang, Anna-Sapfo Malaspinas, Eric Durand and Montgomery Slatkin.
Authors of the preprint destined for PLOS Genetics are Sriram Sankararaman, Nick Patterson, Heng Li, Svante Pääbo and David Reich.
Alan Boyle is NBCNews.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. To keep up with Cosmic Log as well as NBCNews.com's other stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the dwarf planet and the search for new worlds.
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There is no fossil record to support the theory of evolution. That is why it is called a "Theory".
There is no visible field to support the theory of gravitation. That is why gravity is called a "Theory".
There is no visible atom to support the theory of atoms. That is why chemistry is called a "Theory".
There is no visible germ cells to support the theory of sperm. That is why parenthood is called a "Theory".
... and so on. In this case, yes, fossils are visible and they do make the predicted phylogenies. Biology (and its process of evolution) is _better— observed than many other facts.
Bad troll is trolling badly.
I'm guessing that you try to cast doubt on evolution because you possibly believe in creationism.
If that is the case why don't you come up with records that support the Bibles version of mankind?
There is nothing at all to support the faith in a mythical supernatural omnipotent entity ..... that is why it is not even considered a theory.
Sorry Torbjorn Larsson OM but you will encounter many of these myth believers ignorant of science and the majority of posts from them is the last of understanding what the definition of a scientific theory.
These people are immune to debate. Don't even bother.
Yeah, be careful, Dennis. It's a trap!
C'mon, quit arguing, the evidence is overwhelming. The products of this union make up most of the Federal government, and fill the halls of Congress.
Not to mention the corporate boards, CEO's, CFO's, Generals, Field Marshalls, priesthoods, pastors, teachers, police, school crossing guards, etc. etc. etc.
The reality of today is that the house is the only entity making an effort to stop the extinction of the human species while the democratic party agenda is driving the process of extinction for not only the economy, but civilization itself. That agenda has destroyed civilization after civilization throughout all recorded history. The examples of economic insanity of the agendas economic and social lunacy are recent and terrifying, the agenda is never new or improved and is never going to be "better this time". This time around, with a vastly over populated world, it could very well be an extinction event.
Dennis, government-funded infrastructure is the foundation of civilization, not it downfall.
jock ... yes physical infrastructure is a legitimate function of a state and federal government. Socialist programs and taxation for the purpose of redistribution of wealth are not and have repeatedly collapsed economies and civilizations.
BALANCE, Dennis, everything is about balance.
Jock .. again agreed. That is the basic platform of a conservative and the foundation for the original Constitution. The problem today is there is no balance in either political party, both parties are trying to obtain power by making the self-reliant free citizen mindless slaves to the state.
Maybe, Dennis, but at least with the Democrats I get the promise that I will be able to buy health insurance regardless as to my deteriorating condition.
By the way, does anyone know of a way to change your name? I am a bit tired of that stupid number...
And one other point where we disagree, it's the Republicans that refute climate change and still support big oil with billions in subsidies.
Most generals have Masters and Ph.D's in a wide spectrum of programs. I wonder where the myth came from that generals are idiot high school drop outs.
Modern-day Africans, in contrast, have virtually nothing in common with the Neanderthals. The question is what do they have in common with what ? The answer is the most well kept secret of the last 100 years.
It has been suggested that the introduction of neanderthal and denisovan genetic material led to a stronger immune system and the ability for groups larger than the primitive tribal unit to cooperate together. This allowed civilization to form. That theory would explain the empirical evidence of history and today.
Wondering about this are we....read..."Waiting for the Galactic Bus".
I think the question is more "Why wouldn't they interbreed?" Two hominid species of comparable intelligence and similar social structures... It seems like a no-brainer that they would interbreed at various points in time.
I did not make up the Adam and Eve thing.
Maybe not but it sounds like you fell for it.
Did humans and Neanderthals 'do it'?
Perhaps this would explain the Tea party, NASCAR, and your typical Walmart shopper
Geeeez - it's kick a Neanderthal day!!! What next?
There is modern anthropological data to prove they DID interbreed! progressive Demonrats! they are the spawn of global cooling!
And the driving forces of extinction for the species?
real conservatives dont believe in evolution. so you must be hybrids yourselves.
Actually Conservatives do indeed believe in evolution. The religious nuts and self destructive elitist on the left are not conservatives politically.
I live in Wyoming. I'm pretty sure there are still Neanderthals among us. Some of them hold office and serve in the citizen Legislature here... and when they think nobody is looking, they will have sex with all kinds of other animals.
Yes .. it goes under the title of "cultural diversity" and various other social destructive buzzwords.
for anyone to assume that capture did not include rape is to just be stupid. to assume that no woman was captured in those times is really stupid. this isnt disco night gene sharing. rape was probably as common then as driving a car is now. so yeah there was interbreeding on both sides. how could there not have been ? xenophobia came from somewhere too. and i think back then it was pretty damn practical.
You are correct about the typical behaviour that spans across every species of ape.
What so scientist really think and know ? After a 100 years of intensive research and testing the very best minds on the planet agree that Darwin's theory is correct. Something told to them to never reveal to the public.
Hey myth believer posting behind a name of Scientist1 isn't going to hide your ignorance.
land mass was not as it is today, as the earths plates are always on the move. so my thought of the day is that humans were white and turned black to protect them from the sun. i belive i read something to this effect, that the moadic tribe torags (spelling) that live in sub-sahara were orginally white.
Ya, we were all totally albinos, like Adolf Hitler and David Duke
The land masses were not that much different than today. We are talking about the period from 50-500,000 years ago; an eyeblink on the scale of continental drift.
Yes, jock. The kind of idea in Ronald's post, like those of creationists, shows a pretty extreme example of the subversion of rational thought by infantile narcissism (and as such, utterly dismissible). We can safely assume Ronald is white.
Not even addressing the childish statement of Ronald .... you do realise that your examples represent both the extreme left (National Socialism) and the extreme right? You make a strong argument for conservatives.
If you're addressing me and the Hitler/Duke comment, I was just being absurd - you know, like ol' Rushbo - the assumption being that ronald's profound racist undertone, which he would share with Hitler and Duke, can be surmised from an implicit desire to assign the primitive nature of African tribal culture to a kind of retrogressive tendency, rather than assuming that lighter-skinned races developed higher civilizations, along with their lighter skins, as a concomitant of having migrated to latitudes which required greater cooperative efforts to wrest a living from the natural resources. Perhaps the ronalds of the world are truly and ingenuously open to some very, very unlikely possibility that we humans evolved from some white snow monkey type of ape-man, and all human culture had only progressed to a primitive stage of development when these white-ish folks had reached Africa (there to evolve their dark skin), and they remained in a relatively early stage of civilization because of the aforementioned climate-friendliness. But I doubt it, otherwise they would say so, instead of the silly idea that humans floated around on the continents as if the latter were big boats.
Even today, neanderthals are having sex with humans. Neanderthal Republicans with regular humans.
That makes zero sense. The introduction of neaderthal and denisovan genetic material (you suggest republicans when you mean conservatives) in every group of the species except subsahara africa is responsible for the ability to exist in larger groups than primitive tribal groups and made civilization possible as well as a stronger immune system while "regular humans" (by which I assume you mean subsaharan africans and elitist left have an established history of lack of civilization and in the case of the left destruction of civilization. What was your point?
I've had sex with a few Neanderthals.
Must have been a little hairy
GENESIS 6:4 to 6:12 ... then I will break it down to you!!!
4 The Neph´i·lim proved to be in the earth in those days, and also after that, when the sons of the [true] God continued to have relations with the daughters of men and they bore sons to them, they were the mighty ones who were of old, the men of fame.
5 Consequently Jehovah saw that the badness of man was abundant in the earth and every inclination of the thoughts of his heart was only bad all the time. 6 And Jehovah felt regrets that he had made men in the earth, and he felt hurt at his heart. 7 So Jehovah said: “I am going to wipe men whom I have created off the surface of the ground, from man to domestic animal, to moving animal and to flying creature of the heavens, because I do regret that I have made them.” 8 But Noah found favor in the eyes of Jehovah.
9 This is the history of Noah.
Noah was a righteous man. He proved himself faultless among his contemporaries. Noah walked with the [true] God. 10 In time Noah became father to three sons, Shem, Ham and Ja´pheth. 11 And the earth came to be ruined in the sight of the [true] God and the earth became filled with violence. 12 So God saw the earth and, look! it was ruined, because all flesh had ruined its way on the earth.
BREAKDOWN
Nephilm's were offspring of FALLEN Angels who disobeyed God by coming down from the heavens and having sex with Human females. This made them different. Physically stronger , wiser , and more savage than humans. They interbred with humans. This really wasn't in gods plan and most of the human culture was getting wiped out through interbreeding. God chose NOAH to survive the flood and build the arc because he was still PURELY Human. The Nephilm (neanderthals) were the trigger for the great flood in the bible. I write this to the people who havent read this and to the ones that have an open mind. To those that are waiting to give a negative comment.... I DON'T CARE what you have to say. Scientists first discovered Neanderthal bones in 1829. Genesis was written THOUSANDS of years ago. To many biblical scholars.... these bones were NOT a discovery but only gratification. Have a great day :) Scientists will not be able to prove interbreeding. There wasn't anything left alive from Neanderthals. They did not belong on this earth in the first place!!!!
Sounds like a strong case for extra terrestrial intervention by some space astronauts long term presence on earth. That would fit in as a primitive cultures myths and tribal lore passed on as oral lore that became so distorted and changed by each generation that it becomes the basis for the invention of "gods" until finally written down by tribal witchdoctors. You make a strong case! I believe I will wait until there is any scientific evidence to support your personal theory (as opposed to a scientific theory) though. Sounds like you have read "chariots of the gods".
I read the BIBLE. I don't know what "chariots of gods" is. There will be no scientific proof of this. Scientists DOUBT interbreeding because they cant find genetic proof they ever interbred. What I can tell you based on the Bible is that at one point , They interbred on a MASS scale and because of this, they were wiped out along with ANY human that had Neanderthal blood mixed with them. It's a Faith based history book and I cant write anything or say anything to proof this to you in a scientific way. I , myself find humor in this article thought......
You sound like a person who has faith that leprechauns wear blue (or green) without establishing the existence of leprachauns in the first place. The whole issue is that neanderthal and denisovan genetic material is present in every human population group today except subsahara african. That has been pretty much proven beyond any reasonable doubt. If your only source that you use to make your statements is restricted to one source you have no rational basis for forming an opinion.
There is physically no way "the flood" could have happened. Even if so we would see evidence of it. More delusional supernatural mumbo jumbo.
The monkey's are in the trees in Washington DC!
of course they had sex, that's where tea baggers came from, lol
DNA proves that chimpanzees and humans share the same common ancestor. Since they are saying neanderthals were red haired, I am curious if they could've shared the same ancestor as orangutans.
That would be yes, simply another type of ape.
That would explain Carrot Top...
Only virgins and nerds care about this
My wife is still doing it with a Neanderthal.
One of the inplications in this article is that there was an an extreme division between North African populations and sub-Saharan populations, with allmost all of the interactions in the last several hundred thousand years being trans-Mediteranian rather than trans-Saharan. There seems little doubt that present European populations developed in North Africa during long puluvial periods that existed during the last 2 ice ages with an extreme reduction just prior to, or during, the last inter-glacial period.
What was the reason these populations did not associate? Was there always an impenatrable desert between North African populations and South African populations?
No question whatsoever that the inter-breeding happened. Come see my neighbor. He looks like an offspring of the Neanderthals.
Actually if your neighbor were the offsping of Neanderthals that would be evidence against inter-breeding (ie your neighbor would be a pure blood Neanderthal)
In high school my girlfriend said I was a Neanderthal. I always thought she was human for saying so!