African-American's Y chromosome sparks shift in evolutionary timetable

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.

By Alan Boyle, Science Editor, NBC News

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. cosmiclog.nbcnews.com...

In other words more ancient species of us survives in us,I think the Ancient Astronauts theorist should look into this also.

Somewhere out there could be the Jesus Y chromosome. If some of the tales are true and Jesus had children with Mary Magnelane then one would imagine that that Y chromosome would be very old indeed.

P

To be clear, although the article refers to Neanderthals no less than 3 times, dont be mislead since Neanderthals are exclusively European, and not from West Cameroon.

If the abnormal Y chromosome is from breeding with other groups, its not them (or Denisovans).

Originally posted by alfa1

To be clear, although the article refers to Neanderthals no less than 3 times, dont be mislead since Neanderthals are exclusively European, and not from West Cameroon.

If the abnormal Y chromosome is from breeding with other groups, its not them (or Denisovans).

That's as far as we know however it could result from back migration,remember un-derived R is plenty in Cameroon and Chad although it could arise from there.

I still find it amazing that there were... "other" humans! More than 10 different kinds! Imagine what it would be like in a modern age, living side by side with one or more of them. Imagine meeting one. Another intelligent species. The closest thing to alien contact, in a way. Would they be obviously less evolved and less intelligent than us, but with more hightened, animalistic senses and instincts and strength? Or would they be the same, or more intelligent than us?

I watched a scary youtube video that said that they (neanderthals) were killing and raping our women and children (this is where the interbreeding comes from, mass rape and pillaging) and so we finally had to kill them all off... Maybe it was similar with other species, or some were simply killed off by the killing and raping species such as Neanderthal? The hobbit species was very small. Perhaps unable to successfully mount any meaningful defense against the powerful Neanderthal, who were built like a perfect killing machine, with enough intelligence to use fierce weaponry, and enough strength to tear you apart, limb by limb...

Originally posted by 3n19m470
I still find it amazing that there were... "other" humans! More than 10 different kinds! Imagine what it would be like in a modern age, living side by side with one or more of them. Imagine meeting one. Another intelligent species. The closest thing to alien contact, in a way. Would they be obviously less evolved and less intelligent than us, but with more hightened, animalistic senses and instincts and strength? Or would they be the same, or more intelligent than us?

I watched a scary youtube video that said that they (neanderthals) were killing and raping our women and children (this is where the interbreeding comes from, mass rape and pillaging) and so we finally had to kill them all off... Maybe it was similar with other species, or some were simply killed off by the killing and raping species such as Neanderthal? The hobbit species was very small. Perhaps unable to successfully mount any meaningful defense against the powerful Neanderthal, who were built like a perfect killing machine, with enough intelligence to use fierce weaponry, and enough strength to tear you apart, limb by limb...

Maybe we were the aggressor/rapist check out this article from a few yrs ago

How Neanderthals met a grisly fate: devoured by humans A fossil discovery bears marks of butchering similar to those made when cutting up a deer

One of science's most puzzling mysteries - the disappearance of the Neanderthals - may have been solved. Modern humans ate them, says a leading fossil expert. The controversial suggestion follows publication of a study in the Journal of Anthropological Sciences about a Neanderthal jawbone apparently butchered by modern humans. Now the leader of the research team says he believes the flesh had been eaten by humans, while its teeth may have been used to make a necklace. Fernando Rozzi, of Paris's Centre National de la Récherche Scientifique, said the jawbone had probably been cut into to remove flesh, including the tongue. Crucially, the butchery was similar to that used by humans to cut up deer carcass in the early Stone Age. "Neanderthals met a violent end at our hands and in some cases we ate them," Rozzi said. The idea will provoke considerable opposition from scientists who believe Neanderthals disappeared for reasons that did not involve violence. Neanderthals were a sturdy species who evolved in Europe 300,000 years ago, made complex stone tools and survived several ice ages before they disappeared 30,000 years ago - just as modern human beings arrived in Europe from Africa. Some researchers believe Neanderthals may have failed to compete effectively with Homo sapiens for resources, or were more susceptible to the impact of climate change. But others believe our interactions were violent and terminal for the Neanderthals. According to Rozzi, the discovery at Les Rois in south-west France provides compelling support for that argument. Previous excavations revealed bones that were thought to be exclusively human. But Rozzi's team re-examined them and found one they concluded was Neanderthal. Importantly, it was covered in cut marks similar to those left behind when flesh is stripped from deer and other animals using stone tools. Rozzi believes the jawbone provides crucial evidence that humans attacked Neanderthals, and sometimes killed them, bringing back their bodies to caves to eat or to use their skulls or teeth as trophies. "For years, people have tried to hide away from the evidence of cannibalism, but I think we have to accept it took place," he added. But not every team member agrees. "One set of cut marks does not make a complete case for cannibalism," said Francesco d'Errico, of the Institute of Prehistory in Bordeaux. It was also possible that the jawbone had been found by humans and its teeth used to make a necklace, he said. "This is a very important investigation," said Professor Chris Stringer, of the Natural History Museum, London. "We do need more evidence, but this could indicate modern humans and Neanderthals were living in the same area of Europe at the same time, that they were interacting, and that some of these interactions may have been hostile. "This does not prove we systematically eradicated the Neanderthals or that we regularly ate their flesh. But it does add to the evidence that competition from modern humans probably contributed to Neanderthal extinction."
www.guardian.co.uk...

my opinion is...its more about depth than longevity

all this talk about neanderthals and thousandss of years of evolution

things dont change...they havent done in over 6000 years....as far back as we can see

this is just another patrachal move against the maitrachy of the ancients

peace

Originally posted by alfa1

To be clear, although the article refers to Neanderthals no less than 3 times, dont be mislead since Neanderthals are exclusively European, and not from West Cameroon.

If the abnormal Y chromosome is from breeding with other groups, its not them (or Denisovans).

Yeah, this article seems very fishy. Racist?

Here is the full report for folks who would like to see for themselves,don't quiz me just yet I am still looking at it.
haplogroup-a.com...

Is this article in reference to the same research?
Father of all humanity is 340,000 years old

If so it seems to have a different focus...

All previously compared DNA samples pointed to a common Y chromosome traced back to man who lived between 60,000 and 140,000 years ago....
... University of Arizona researcher Michael Hammer says Perry’s DNA suggests there may have been an earlier species of humans that went extinct —but not before interbreeding with the more modern version of man.

maybe im just reading it wrong?

Originally posted by RadicalRebel
Is this article in reference to the same research?
Father of all humanity is 340,000 years old

If so it seems to have a different focus...

All previously compared DNA samples pointed to a common Y chromosome traced back to man who lived between 60,000 and 140,000 years ago....
... University of Arizona researcher Michael Hammer says Perry’s DNA suggests there may have been an earlier species of humans that went extinct —but not before interbreeding with the more modern version of man.
maybe im just reading it wrong?

No you are on point and Alfa may have got it right also,question is who were these extinct humans.
Alfa1

To be clear, although the article refers to Neanderthals no less than 3 times, dont be mislead since Neanderthals are exclusively European, and not from West Cameroon. If the abnormal Y chromosome is from breeding with other groups, its not them (or Denisovans).

edit on 9-3-2013 by Spider879 because: messed-up