posted
Ancient cousin of humans identified by scientists
An ancient cousin of modern-day humans which once shared the earth with the Neanderthals has been identified by scientists.
The bone, along with a tooth fragment, was discovered in the Denisova cave in southern Siberia Photo: NATIONAL
DNA taken from the 30,000 year old finger bone of a young girl was found to be neither from early human nor Neanderthal, and was from a previously unknown species, now called Denisovan.
The bone, along with a tooth fragment, was discovered in the Denisova cave in southern Siberia, and its DNA was found to be distinct from human or Neanderthal.
Researchers say that like Neanderthals, Denisovans interbred with early humans, and traces of their DNA can be found in modern day Melanesians - those from the islands around Papua New Guinea.
Scientists say they would have inhabited land across Asia, only to become extinct alongside the Neanderthals as early humans thrived.
The bone was found in 2008 by Russians, and examined by a team led by Svante Pääbo of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany.
They compared the Denisovan genome sequence to the recently unravelled Neanderthal genome, as well as to modern humans.
Denisovans were found to be a sister group to Neanderthals, and had descended from the same ancestors who split from the ancestors of modern humans.
Scientists had known that Neanderthals and early humans had interbred, as there is Neanderthal DNA in all non-African humans.
But they found that Denisovans also interbred with humans - and traces of their genes are found in modern-day Melanesians, suggesting the cavemen travelled widely across Asia, reports Nature.
Professor Richard Green of the University of California, Santa Cruz, said: "The story now gets a bit more complicated.
"Instead of the clean story we used to have of modern humans migrating out of Africa and replacing Neanderthals, we now see these very intertwined story lines with more players and more interactions than we knew of before.
"It was fortuitous that this discovery came quickly on the heels of the Neanderthal genome, because we already had the team assembled and ready to do another similar analysis.
"This is an incredibly well-preserved sample, so it was a joy to work with data this nice.
"We don't know all the reasons why, but it is almost miraculous how well-preserved the DNA is."
He said that the Denisovans were "quite different both genetically and morphologically from Neanderthals and modern humans", with the tooth similar to those of much older human ancestors, such as homo erectus.
It was unclear why the species had not been discovered before - but Prof Green said that because both the bone and the tooth, which came from different members of the same population, resembled those of earlier humans other finds may have been overlooked.
He said: "It could be that other samples are misclassified.
"But now, by analysing DNA, we can say more definitively what they are.
"It's getting easier technically to do this, and it's a great new way to extract information from fossil remains."
Prof Green said the evidence now suggests that an ancestral group of early humans left Africa up to 400,000 years ago and diverged, with one branch heading to Europe and becoming the Neanderthals and a second moving east and becoming Denisovans.
When modern humans left Africa - some 80,000 years ago - they came into contact with first the Neanderthals before another group interbred with Denisovans, the traces of which now exist in Melanesia.
Prof Green said: "This study fills in some of the details, but we would like to know much more about the Denisovans and their interactions with human populations.
"And you have to wonder if there were other populations that remain to be discovered. Is there a fourth player in this story?"
posted
Every day discoveries are being made, loosening the grip of the pseudo-OOA parentage, a parentage enjoyed by Afrocentrists for quite some time now. The "Negrito" stock, commonly linked to continental Sub-saharan Negroes is officially 'BUNKED. Science is wonderful! Fallacies are falling apart by the minute!
Posts: 1340 | Registered: Apr 2010
| IP: Logged |
posted
^^Exactly how does finding this new species falsify the OOA model accepted by most scientists?
-------------------- Note: I am not an "Egyptologist" as claimed by some still bitter, defeated, trolls creating fake profiles and posts elsewhere. Hapless losers, you still fail. My output of hard data debunking racist nonsense has actually INCREASED since you began.. Posts: 5905 | From: The Hammer | Registered: Aug 2008
| IP: Logged |
posted
You are a fvcking fool if you do not see that evidence is pointing to humanity having multiple origins. Oh yea, and no one disputes continental origin. It is the Afrocentrist origin of race that is being shattered.
quote:Originally posted by zarahan: ^^Exactly how does finding this new species falsify the OOA model accepted by most scientists?
quote:^^Exactly how does finding this new species falsify the OOA model accepted by most scientists?
Confirming Truth has proven his lack of facility with numbers yet again. The Denisovan genetic contribution to the population of New Guinea is less than 1/20.
Posts: 1038 | From: Franklin Park, NJ | Registered: Aug 2005
| IP: Logged |
posted
You're so desperate for OOA to be dis-proven it's ridiculous the imbecilic conclusions you come up with and lengths you'll go to.
Anyone with a brain who has read the below knows you're the only fool here.
quote:DNA taken from the 30,000 year old finger bone of a young girl was found to be neither from **early human** nor Neanderthal , and was from a previously unknown species, now called Denisovan..[..]..Denisovans were found to be a sister group to Neanderthals, and had descended from the same ancestors who split from the ancestors of modern humans. Scientists had known that Neanderthals and early humans had interbred, as there is Neanderthal DNA in all non-African humans. But they found that Denisovans also interbred with humans - and traces of their genes are found in modern-day Melanesians, suggesting the cavemen travelled widely across Asia, reports Nature.
^^The above does not in the least imply that modern humans descend from Denisovans nor Neanderthal. Keep dreaming I guess.
If you don't want to be part of the anatomically modern human family, and instead be a Neanderthal or Denisovan you can always dream.
Posts: 6572 | From: N.Y.C....Capital of the World | Registered: Jun 2008
| IP: Logged |
quote:An international team of scientists has identified a previously shadowy human group known as the Denisovans as cousins to Neanderthals who lived in Asia from roughly 400,000 to 50,000 years ago and interbred with the ancestors of today’s inhabitants of New Guinea.
All the Denisovans have left behind are a broken finger bone and a wisdom tooth in a Siberian cave. But the scientists have succeeded in extracting the entire genome of the Denisovans from these scant remains. An analysis of this ancient DNA, published on Wednesday in Nature, reveals that the genomes of people from New Guinea contain 4.8 percent Denisovan DNA.
An earlier, incomplete analysis of Denisovan DNA had placed the group as more distant from both Neanderthals and humans. On the basis of the new findings, the scientists propose that the ancestors of Neanderthals and Denisovans emerged from Africa half a million years ago. The Neanderthals spread westward, settling in the Near East and Europe. The Denisovans headed east. Some 50,000 years ago, they interbred with humans expanding from Africa along the coast of South Asia, bequeathing some of their DNA to them.
“It’s an incredibly exciting finding,” said Carlos Bustamante, a Stanford University geneticist who was not involved in the research.
The research was led by Svante Paabo, a geneticist at the Max Planck Institute for Evolutionary Anthropology in Liepzig, Germany. Dr. Paabo and his colleagues have pioneered methods for rescuing fragments of ancient DNA from fossils and stitching them together. In May, for example, they published a complete Neanderthal genome.
The stocky, barrel-chested Neanderthals left a fossil record stretching from about 240,000 to 30,000 years ago in Europe, the Near East and Russia. Analyzing the Neanderthal genome, Dr. Paabo and his colleagues concluded that humans and Neanderthals descended from common ancestors that lived 600,000 years ago.
But the scientists also found that 2.5 percent of the Neanderthal genome is more similar to the DNA of living Europeans and Asians than to African DNA. From this evidence they concluded that Neanderthals interbred with humans soon after they emerged from Africa roughly 50,000 years ago.
quote: Published online 22 December 2010 | Nature 468, 1012 (2010) | doi:10.1038/4681012a
News Fossil genome reveals ancestral link ------------------------------------ A distant cousin raises questions about human origins.
Ewen Callaway
The ice-age world is starting to look cosmopolitan. While Neanderthals held sway in Europe and modern humans were beginning to populate the globe, another ancient human relative lived in Asia, according to a genome sequence recovered from a finger bone in a cave in southern Siberia. A comparative analysis of the genome with those of modern humans suggests that a trace of this poorly understood strand of hominin lineage survives today, but only in the genes of some Papuans and Pacific islanders.
A finger bone and a tooth (inset) from Denisova Cave have illuminated a mysterious strand of hominin. B. VIOLA, MPI EVA
Named after the cave that yielded the 30,000–50,000-year-old bone, the Denisova nuclear genome follows publication of the same individual's mitochondrial genome in March(1). From that sequence, Svante Pääbo of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, and his colleagues could tell little, except that the individual, now known to be female, was part of a population long diverged from humans and Neanderthals.
Her approximately 3-billion-letter nuclear genome, reported in this issue of Nature(2), now provides a more telling glimpse into this mysterious group. It also raises previously unimagined questions about its history and relationship to Neanderthals and humans. "The whole story is incredible. It's like a surprising Christmas present," says Carles Lalueza Fox, a palaeogeneticist at Pompeu Fabra University in Barcelona, Spain, who was not involved in the research.
When the ancient genome was compared to a spectrum of modern human populations, a striking relationship emerged. Unlike most groups, Melanesians — inhabitants of Papua New Guinea and islands northeast of Australia — seem to have inherited as much as one-twentieth of their DNA from Denisovan roots. This suggests that after the ancestors of today's Papuans split from other human populations and migrated east, they interbred with Denisovans, but precisely when, where and to what extent is unclear.
More answers could come from a closer look at Denisovan, human and even Neanderthal DNA. So far, conclusions about interbreeding have been drawn from a relatively small number of human genomes using conservative DNA-analysis methods, says David Reich, a geneticist at Harvard Medical School in Boston, Massachusetts, who led the Denisova analysis. "There may have been many more interactions," he says. Pääbo says it may be possible to determine roughly when humans interbred with Denisovans by examining the length of DNA segments lurking in various human genomes, with shorter segments corresponding to more shuffling of genes and a longer elapsed time.
A molar discovered in the same cave also yielded mitochondrial DNA resembling that of the finger bone. But the Denisovans were probably more widespread, says Pääbo. Some fossils from China, for example, resemble neither Neanderthals nor modern humans — nor Homo erectus, an earlier human ancestor. Pääbo wonders whether they could be more closely related to Denisovans. His Russian collaborators plan to search for more complete Denisovan fossils that could be matched to others from China.
Chris Stringer, a palaeoanthropologist at London's Natural History Museum, agrees that Asian fossils, such as the 200,000-year-old Dali skull from central China, could have links to the Denisovans. But he says that firm conclusions about such relationships will have to await the discovery of more complete Denisovan fossils.
Preserved DNA from other Asian fossils would also provide a clearer picture of the Denisovans, which Pääbo, to sidestep controversy, has opted not to call a new species or subspecies of hominin. The challenge will be to make sense of such discoveries and put them in the context of ancient human history, says Lalueza Fox. Palaeoanthropologists are just beginning to scrutinize the Neanderthal genome published earlier this year(3) for clues to ancient human history. With the Denisova genome, "they will need to deal with another surprise", he says.
quote: Genetic history of an archaic hominin group from Denisova Cave in Siberia
David Reich, Richard E. Green, Martin Kircher, Johannes Krause, Nick Patterson, Eric Y. Durand, Bence Viola, Adrian W. Briggs, Udo Stenzel, Philip L. F. Johnson, Tomislav Maricic, Jeffrey M. Good, Tomas Marques-Bonet, Can Alkan, Qiaomei Fu, Swapan Mallick, Heng Li, Matthias Meyer, Evan E. Eichler, Mark Stoneking, Michael Richards, Sahra Talamo, Michael V. Shunkov, Anatoli P. Derevianko, Jean-Jacques Hublin,Janet Kelso, Montgomery Slatkin & Svante Pääbo et al.
Journal name:Nature Volume:468, Pages:1053–1060 Date published:(23 December 2010) DOI: doi:10.1038/nature09710Received 15 August 2010 Accepted 30 November 2010 Published online 22 December 2010
ABTRACT
Using DNA extracted from a finger bone found in Denisova Cave in southern Siberia, we have sequenced the genome of an archaic hominin to about 1.9-fold coverage. This individual is from a group that shares a common origin with Neanderthals. This population was not involved in the putative gene flow from Neanderthals into Eurasians; however, the data suggest that it contributed 4–6% of its genetic material to the genomes of present-day Melanesians. We designate this hominin population ‘Denisovans’ and suggest that it may have been widespread in Asia during the Late Pleistocene epoch. A tooth found in Denisova Cave carries a mitochondrial genome highly similar to that of the finger bone. This tooth shares no derived morphological features with Neanderthals or modern humans, further indicating that Denisovans have an evolutionary history distinct from Neanderthals and modern humans.
Figure 1: A neighbour-joining tree based on pairwise autosomal DNA sequence divergences for five ancient and five present-day hominins.close Vindija 33.16, Vindija 33.25 and Vindija 33.26 refer to the catalogue numbers of the Neanderthal bones
Figure 2: Relationship of present-day populations to the Denisova individual and Neanderthals based on 255,077 SNPs. Principal component analysis of the means of 53 present-day human populations projected onto the top two principal components defined by Denisova, Neanderthal and chimpanzee. The seven ‘African’ populations are San, Mbuti, Biaka, Bantu Kenya, Bantu S…
posted
Nice article but it is an attempt to attack the Out of Africa idea. This paper claims that the Melanesians are related to some ancient group that lived in Siberia in the ancient past.
This theory is bull. If you read the article they provide no firm dates for this hominid--so their conclusion lacks any validity due to the fact their findings are not reliable.
The Melanesian language is related to West African languages. They also share many placenames with West Africans and probably only arrived in the Pacific region with megalithic culture which only entered the area after 2000BC. So there is no way they met this population over 60kya.
The journal Nature like the European Journal of Human Genetics is very Eurocentric. They rarely publish any letters to the editor disputing their findings--which usually aim to isolate Africans in Africa, and Africans being influenced by Europeans and Asians carrying African genes through a back migration.
The recent discovery of African skeletons in China that are 100ky old suggest that the OOA event probably took place much earlier than the precent agreed upon date of 60kya.
You can read about the Chinese skeletal fine here:
1.[Liu:Zhirendong:2010] Liu, Wu, et al. "Human remains from Zhirendong, South China, and modern human emergence in East Asia." Proceedings of the National Academy of Sciences (Early online).
.
.
-------------------- C. A. Winters Posts: 13012 | From: Chicago | Registered: Jan 2006
| IP: Logged |
Scientists found evidence that in the genomes of people now living in Melanesia, about 5 percent of their DNA can be traced to Denisovans, a sign of ancient interbreeding that took researchers by surprise.
"We thought it was a mistake when we first saw it," Reich said. "But it's real." And that suggests Denisovans once ranged widely across Asia, he said. Somehow, they or their ancestors had to encounter anatomically modern humans who started leaving Africa some 55,000 years ago and reached New Guinea by some 45,000 years ago.
Neanderthal, Denisovan, and Modern all have the same great great grandparent way down the line but each is a distinct hominin population, not a one being a parent to the other.
Cousins have the same grandparent. One cousin can't be the parent of another cousin but two cousins can produce offspring. That progeny of a Denisovan-Modern offspring were absorbed by that Modern lineage leading up to certain Oceana regional populations is what Reich et al imply.
In the dozens of news articles about the Denisovan many irresponsibly use the word ancestor, a claim Reich et al never make.
As a counterpoint to Papuans and Melanesians sharing in the Denisovan genome a non-team member
quote:Rick Potts, director of the human origins program at the Smithsonian Institution, said the Melanesia finding could mean that the Melanesians and the Denisovans didn't intermix, but simply happened to retain ancestral DNA sequences that had been lost in other populations sampled in the study.
If anything, the Liu,Trinkhaus et al report attacks OoA theory.
Posts: 8014 | From: the Tekrur in the Western Sahel | Registered: Feb 2006
| IP: Logged |
posted
Neanderthals do not support an ancient existence of the contemporary European type. Neanderthals like other ancient homonids looked African.
These researchers fail to remind people that some of the earliest neanderthal remains come from Africa. This being the case Neanderthals were also Black.
Europeans have invented a lie that Neanderthal looked like modern Europeans when they did not. I show a picture of the recreation of Neanderthals in my video below at 3:35 :
As you can see the Neanderthal looked African too. They are using the myth of European appearing Neanderthals to fool people into believing that Africans are not their ancestors. Sad is it not.
-------------------- C. A. Winters Posts: 13012 | From: Chicago | Registered: Jan 2006
| IP: Logged |
UBBFriend: Email this page to someone!
Printer-friendly view of this topic