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University of Arizona
A photomicrograph shows an X chromosome at left, alongside a shrunken Y chromosome. The Y chromosome is passed down exclusively from father to son and can serve as an indicator of male-line human diversity.
Scientists say an African-American male's odd genetic signature suggests that the human Y chromosome's lineage goes back further in time than they thought — perhaps due to interbreeding with other populations such as Neanderthals.
"This really upsets a lot of ideas, but at the same time, it's understandable if we accept that human populations were structured in the past so that there were little pockets of diversity," said Michael Hammer, an evolutionary biologist at the University of Arizona who is one of the authors of a study published in the American Journal of Human Genetics.
The study focuses on the analysis of a DNA sample that was obtained from an African-American living in South Carolina and submitted to the Genographic Project, a National Geographic effort aimed at mapping human origins and migration. The funny thing about this sample is that it didn't match up with any of the previously known genetic signatures for the Y chromosome, which is passed down from father to son.
"Nobody expected to find anything like this," Hammer said in a news release.
A team led by Fernando Mendez, a researcher in Hammer's lab, analyzed more than 240,000 DNA base pairs on the African-American's Y chromosome. A comparison of the differences between the mystery genetic signature and previously known signatures led the team to conclude that the most recent common ancestor for the entire group lived about 338,000 years ago.
That goes further back than the fossil record goes for anatomically modern humans, Hammer said. "The fossil record speaks to 195,000 years or 200,000 years," he said. It also goes further back than the previous date for the most recent common ancestor based on Y-chromosome analysis, which is in the range of 142,000 years.
The researchers followed up on their discovery by searching through a genetic database for African populations, and turned up 11 men from western Cameroon who had virtually the same genetic signature.
Hammer said there could be two explanations for the previously unidentified Y-chromosome type: Either the genetic heritage of anatomically correct humans really does go back much further than what's reflected in the fossil record — or other populations, such as Neanderthals or the more recently identified Denisovans, interbred with modern humans. Anthropologists refer to that pattern of divergence followed by renewed interbreeding as introgression.
The results are "more consistent with introgression of an odd lineage," Hammer told NBC News. Over the past few years, scientists have been coming around to the view that such interbreeding did take place early in the history of our species. Recent analysis of Neanderthal and Denisovan DNA has indicated that a part of their genetic heritage survives in modern-day humans.
Melissa Wilson Sayres, a geneticist at the University of California at Berkeley who played no role in Hammer's study, said the new findings were "exciting" because they pointed to a Y-chromosome lineage more ancient than any others. "They just happened to come across this one Y chromosome that was hidden for so long, and it's very likely that there are more hidden Y chromosomes around the world," she told NBC News.
She said one of the biggest debates in the study of human genetics has to do with how to match mutation rates with time scales — and she expects this latest study to add to the debate. For example, some might continue to argue that the most recent common ancestor lived more recently than 338,000 years ago. "It will still be the oldest Y-chromosome heritage that we have, but I can foresee that some people might disagree with that specific age," she said.
More about our genetic origins:
- Y chromosome is an evolutionary marvel
- Humans had sex with now-extinct relatives
- So who didn't have sex with Neanderthals?
In addition to Hammer and Mendez, the authors of "An African American Paternal Lineage Adds an Extremely Ancient Root to the Human Y Chromosome Phylogenetic Tree" include Thomas Krahn, Bonnie Schrack, Astrid-Maria Krahn, Krishna R. Veeramah, August E. Woerner, Forka Leypey Mathew Fomine, Neil Bradman, Mark G. Thomas and Tatiana M. Karafet. The authors acknowledged Jacqueline Johnson and her male cousins, the descendants of Albert Perry (South Carolina) and participating Family Tree DNA customers.
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 controversial dwarf planet and the search for new worlds.
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The author suggests interbreeding with Neanderthals, sorry it wasn't Cro-Magnons.
anymore it sems, who didnt interbreed with neanderthals is the more appropiate question. Neanderthals were the Hugh Hefners of the ancient world it seems.
Humans breeding with Cro-Magnons wouldn't be interbreeding, given that we ARE Cro-Magnons. Cro-Magnons are Homo sapiens sapiens, the ancestors of modern humans.
Neanderthals must have been a good lay.
Yeah, right .. Ever time you people study something, you come up with something different... It would be easier and cost a lot less just to write down, "I DON"T KNOW >>" >>
But that's what science is: seeking the truth through study of our environment, and changing it if they find new evidence. They have a certain set of conditions and based their conclusions on that, and when something new is found they change their findings. Otherwise, why ever release any data? You would always wonder if something new will be found that will change it.
Right...but when seemingly every new piece of data requires a major re-working of the narrative, the governing theory itself *should* be questioned. But not in this field. Instead we get tweak layered-upon tweak just to keep things on the rails. Get the theory right--like Einstein did with special relaitvity for instance--and the data doesn't create problem after problem. We clearly have no idea what's going on with human evolution, and for some reason the current scientific orthodoxy seems committed to keeping it that way.
Yeah, I say we just invent a story about how stuff was made and stick to it.
Okay Andy from uptown. . .YOU DON'T KNOW. There, feel better?
Mike - Why do you think that this therory shouldn't be questioned? What is it that you are afraid is going to be discovered?
Don, Mike is worried that the evidence gets stronger that mankind evolved from Africa, you know, (whisper) black people, instead of the white Adam and Eve.
It took more than 2500 years to get our current understanding of universal gravitation from Thales' first observations of the sky. Some of the most famous names in all science spent years on the problem: Aristotle, Ptolemy, Copernicus, Kepler, Newton. All of them got it wrong before Einstein came along with general relativity, and even now there are still unanswered questions! More tweaking is needed.
If it took 2500 years to tweak gravity into shape. The study of ancient humans has been chugging along for maybe 150. Give it some time.
Uptownandy -
Just because you lack curiosity about the world around you doesn't mean the rest of us desire to - or should - remain ignorant. I for one, am completely relieved that people like you are going the way of the dinosaurs. (The dinosaurs, by the way, existed millions of years ago; and contrary to what you might believe, god didn't put here to test our faith.)
Who said Adam and Eve were white brainiac? All we can do is give our best advice, theory, or idea as to where humans even originated from. The best guess so far is somewhere in Africa around Ethopia last time I checked.
What I find interesting is the diversity of people, eyes, noses, skin color etc yet we all origanted from one comman place and this study suggests we were not much different looking today than we were 200K+ years ago.
Actually, that is exactly what IS being done. This article discusses how the governing theory should be questioned.
Or "by governing theory", are you suggesting that the scientific method is invalid because we have come across new data?
He's suggesting God did it.
Why write, "I don't know" when we do, and CAN KNOW?
[Michael Shermer]
Science is the best tool ever devised
For understanding how the world works
[Jacob Bronowski]
Science is a very human form of knowledge
We are always at the brink of the known
[Carl Sagan]
Science is a collaborative enterprise
Spanning the generations
We remember those who prepared the way
Seeing for them also
[Neil deGrasse Tyson]
If you're scientifically literate,
The world looks very different to you
And that understanding empowers you
[Richard Dawkins]
There's real poetry in the real world
Science is the poetry of reality
[Sagan]
We can do science
And with it, we can improve our lives
[Jill Tarter]
The story of humans is the story of ideas
That shine light into dark corners
[Lawrence Krauss]
Scientists love mysteries
They love not knowing
[Richard Feynman]
I don't feel frightened by not knowing things
I think it's much more interesting
[Brian Greene]
There's a larger universal reality
of which we are all a part
[Stephen Hawking]
The further we probe into the universe
The more remarkable are the discoveries we make
[Carolyn Porco]
The quest for the truth, in and of itself,
Is a story that's filled with insights
[Greene]
From our lonely point in the cosmos
We have through the power of thought
Been able to peer back to a brief moment
After the beginning of the universe
[PZ Myers]
I think that science changes the way your mind works
To think a little more deeply about things
[Dawkins]
Science replaces private prejudice
With publicly verifiable evidence
I think that was brainiac's point, Jonathan.
Science exists precisely because we don't know.
The more you learn, the more you realize how little you know.
Ignorance is bliss.
There have been enough studies of Cro-Magnon and Neanderthal DNA to conclude there was no interbreeding.
Bzzzzt wrong. The_Mick fails again.
Mick - obviously there hadn’t been enough studies. If you were truly an enlightened person who understood the concept of Science, you would be saying that obviously there hadn’t been enough studies on this subject.
If modern day man will do about anything from sheep to camels to whatever he can fit it in I think there definitely was interbreeding back then. Man sure hasnt changed much.... :)
And sofas!
http://www.huffingtonpost.co.uk/2012/09/27/wisconsin-man-gerard-streator-arrested-having-sex-with-sofa_n_1918400.html
I wonder if they've mapped out furniture genetics?
Mick. the genetic record points to the proposition that interbreeding did take place, which would be in keeping with some fossilized bones that show both Neanderthal and Homo sapien traits. What's throwing me, though, is that Africans were the only group that did not show any interbreeding with Neanderthals, which pointed to an "out of Africa" migration pattern. So how can some Cameroonians show Neanderthal genes, unless Neanderthals evolved in Africa, or the Cameroonians have interbred with Europeans or Asians? Logically, we can rule out Neanderthal genes, which leaves Denisovans or perhaps another unknown group.
As for scientists being confused, knowledge is accumulative and cannot be collected without research, which means that there will be errors. However, the difference between science and faith is that truth in science has to be replicated. Therefore, scientists are not allowed to jump to conclusions, although many basic premises are often wrong.
It is pretty much a given that subsahara groups did not interbreed with Neanderthal or Denisovan group. I think what they are trying to assert is they found DNA of pre-human ancestor of both groups Neanderthal and HomoSapien. Jumping to fantasy conclusions and media hype. Somehow 12 examples out of 7 billion+ the more likely conclusion is something really really weird was taking place in a very isolated group with very very few individuals, otherwise it would show in the widespread populations throughout the world if it had any evolutionary significance.
Brenda and Dennis -- the problem is the wording used in the article here. He wrote "other populations *such as* Neanderthals." Alan Boyle may or may not have understood that while the population that could have introgressed would have been archaic, they were definitely not Neanderthals (or Denisovans). We would never think of suggesting that they were. It would hae been helpful for Alan Boyle to have been a bit clearer to specify that it would have been an archaic human population native to Africa, not the Neanderthals, who of course inhabited Eurasia.
If you read a little more, you'll find, for example recently in The New Scientist, that Chris Stringer, one of the most respected paleoanthropologists, has been involved in studying the Iwo Eleru skull from Nigeria, and has pointed out that this represents a human population with some archaic features -- very unlike contemporary Africans -- who lived as recently as 13,000 years ago, according to the latest dating methods. That location is quite close to Western Cameroon. There aren't any remains that have been specifically identified as representing the archaic population that would have been involved, but there are strong hints of that kind.
Dennis, I hope it's not our work you're seeing as jumping to fantasy conclusions. Please read the original article before jumping to your own conclusions. There are many more than 12 Y-chromosomes in this group; that was only the number whose samples were readily available to include in the study. Likely there are at least a couple of thousand males with the A00 Y chromosome, if not more. You are incorrect to suggest that something would have to be present in widespread populations around the world for it to have evolutionary significance. According to science, humans did evolve in Africa, and that is where we can still find traces of the early footprints of human ancestors. This isn't the place for a detailed response, but in any case, please read our actual work, or at least more detailed summaries, before you make up your mind that we don't know what we're talking about.
Check out this study and let us know what you think. It was done on the Maternal DNA of African Americans.
The acorn doesn't fall far from the tree, really . . .
Really!
This suggests that not enough is known about the DNA of people who live in, or whose ancestors lived in, West Africa (as opposed to East Africa, which appears to have been the staging area for human settlement of other continents). This would be an important subject for research.
Odd conclusion by the researcher. After being able to obtain Neanderthal DNA it was found that every grouping the planet contain Neanderthal,Denisovan genetic showing interbreeding took place .... all but one that is, subsahara africa group. For such a minscule number of a specific group to show oddity is more likely that something really weird was going on to very very very few in an isolated region. For 12 examples out of 7 billion plus I think they better rethink a bit, I realise the excitement of finding an abnormality but jumping into flights of fantasy is unscientific.
and yet the "young earther" religious wingnuts claim the earth is only 6000 years old...
Humans couldn't get this screwed up in 6000 years. We've obviously been here longer.
You're right, Bob. The genome project has shown that East Indians are closely related to East Africans.
Right, Bob! The genome project has shown that East Asians are closely related to East Indians.
Dennis, I think researchers have not tested enough of the population to know just how much of an aberration that Y chromosome is. Likely, there were other groups very early on thatwe do not know about.
Well I was thought to believe that I was created from a mans rib. An it took me over 30 years to figure out that wasn't right. So I guess it may take a little longer to figure out the whole origin of the homo sapien.
Very interesting article. I think it partically elludes that the black race dates back before more modern races. This goes back to all races coming from the black race. This is not racial or is intended to open up idiotic useless dialog. And if this is the case, one has to begin to look at the bible in a very very different manner!! There is simply no way the tropical region of the bible era was anything close to being that of the northern Caucus regions. Which should tell any positive thinker that the media has been purposely misguiding for years.
Not sure which is the more shocking implication in this article: that racial differences actually go beyond "social constructs," or that there's a black guy with an unknown father.
Who said Africa was always full of black people, just look at North Africa today. Look at ancient Egypt, I wouldn't say those people were exaclty a negroid species.
Black people did live in regions like Egypt. The black people were conquered by the Arabs. So today some Egyptians would be a mix of black and Arab.
Not all black people were conquered by Arabs. The Moors only conquered certain parts of Africa and Europe.
TonyInDallas, The original Arabs were black and the Moors have been around the planet and in Space.
MissShae, everyone is descended from dark skinned people.
However, the question of whether Arabs were black or not is irrelevant to this conversation. My answer was to callas13's comment about blacks being conquered by Arabs. The skin color of the Arabs was not part of the consideration, unless we are talking about Arabs conquering Arabs, which was not implied in the original post of callas13.
Cool. Science.
This can't be true...its not in the bible :)
This can't be true...it's not in the bible :)
UsaidWhat we get it; your an ignorant a$$h0le...so stop reposting the same thing.
Racism simply shows the ignorance of the racist person.
As Mark Twain so eloquently put it:
“It is better to keep your mouth closed and let people think you are a fool than to open it and remove all doubt.”
lifewatchgroup org
Read the results of this study done by the University of South Carolina. They did a study on the Maternal DNA of African Americans and found that 40% of the samples could not be linked to known haplo-groups in Africa. The study was fairly extensive. The info in this article coupled with the study done by the University of South Carolina is very remarkable. One can reasonably draw the conclusion that many African-Americans descend from a very old sub-race that has either been extinguished, or hidden in very remote regions of the earth.
It could be that black males were brought from Africa to places in the Americas like Cuba and Haiti, where they were bred with the local populations. This would place the mitochondrial DNA in the Americas, with populations that were effectively wiped out of existence through war and disease.
Now, this is plausible. Racial diversity is a direct result of racial slavery because of the lawlessness associated with breeding. DNA is complex and not as homogenous as it 250,000 years ago. Therefore, these researchers cannot attribute their finds to a possible earlier existence of Neanderthals or Europeans. Again, a group of researchers are trying to definitively explain the origins of Caucasoids by linking Africoids to a much later timeline. Impossible.
And I quote "perhaps due to interbreeding with other populations such as Neanderthals." or as a simian sub-species of human - apes and monkeys!!!
Makes sense... interbreeding with neandrathals, apes, monkeys... totally makes sense, I mean look at them
". . . totally makes sense, I mean look at them"
I am actually looking at your profile pic. Wonder what makes sense when analyzing you? What breeding created those weak eyes, high forehead, long nose, and super thin lips?
See how nasty comments can be?
Don't compare us to apes. Apes have more morals.
If this "Y" thingie dates back to BEFORE the Neanderthals then that means they would 'interbreed' with anything that moved, Neanderthal would be a normal thing to them. It has been discovered there was a limited amount of interbreeding with the Cro Magnon and the Neanderthals - and they were alleged to be the first known European humans - the Cro more sohisticated, intelligent and advanced than the Neander's. The Neanders were the 'gutteral' part of the human beings and less modern in their shape and body formation. They were called 'flatheads' because of the shape of their skulls, much like ape's! So, if blacks were 'discovered' to have existed somewhere and remained undiscovered that means they hit on anything that moved - could this prove Darwin's theory?
The thing I find rather humerous is that the blacks are STILL inbreeding! LOL!
No more than whites.