They're getting closer and closer and closer...to the truth. I made a few notes, denoted in brackets within the text.
From The New York Times, July 4, 2017, by Carl Zimmer:
In Neanderthal DNA, Signs of a Mysterious Human Migration
With fossils and DNA, scientists are piecing together a picture of humanity’s beginnings, an origin story with more twists than anything you would find at the movie theater.
The expert consensus now is that Homo sapiens evolved at least 300,000 years ago in Africa. Only much later — roughly 70,000 years ago — did a small group of Africans establish themselves on other continents, giving rise to other populations of people today.
To Johannes Krause, the director of the Max Planck Institute for Human History in Germany, that gap seems peculiar. “Why did people not leave Africa before?” he asked in an interview. After all, he observed, the continent is physically linked to the Near East. “You could have just walked out."
In a study published Tuesday in Nature Communications, Dr. Krause and his colleagues report that Africans did indeed walk out — over 270,000 years ago.
Based on newly discovered DNA in fossils, the researchers conclude that a wave of early Homo sapiens, or close relatives of our species, made their way from Africa to Europe. There, they interbred with Neanderthals.
Then the ancient African migrants disappeared. But some of their DNA endured in later generations of Neanderthals.
"This is now a comprehensive picture,” Dr. Krause said. “It brings everything together."
Showing posts with label Denisovan man. Show all posts
Showing posts with label Denisovan man. Show all posts
Sunday, July 9, 2017
Friday, March 3, 2017
New Species of Human Discovered in China? Possibly...
From The Washington Post
Ben Guarino
March 3, 2017
Skulls found in China were part modern human, part Neanderthal; possibly new species
Modern humans outlasted the Neanderthals by about 40,000 years and counting. But don’t pat yourself on the back too firmly for outliving those troglodytes. Neanderthals crafted tools and tamed fire. They cared for their dead. Animal horns and blackened fire pits encircling the remains of a Neanderthal toddler suggest a 42,000-year-old funeral rite. If a Neanderthal indeed wore a talon necklace, as a collection of polished eagle claws indicate, they beat us to jewelry, too. Perhaps one of your ancient ancestors found the claw necklaces sexy: Some scientists theorize humans gave Neanderthals genital herpes and tapeworm parasites. Their proportions, however, remained distinctly Neanderthal. Neanderthal bodies were shorter and stockier, more Gimli son of Gloin than Gigi Hadid. Their skulls were built differently, too, with a few features — like heavy brow ridges — particularly unlike ours. Which makes a pair of newly described skulls something of a wonder. The partial skulls have features up to this time unseen in the hominid fossil record, sharing both human and Neanderthal characteristics. “It is a very exciting discovery,” as Katerina Harvati, an expert in Neanderthal evolution at the University of Tübingen in Germany, who was not involved with the research, told The Washington Post. “Especially because the human fossil record from East Asia has been not only fragmentary but also difficult to date.” Excavators dug up the skull cap fragments in 2007 and 2014, in Lingjing, located in China’s Henan province. The diggers discovered two partial skulls in a site thought to be inhabited 105,000 to 125,000 years ago, during an epoch called the Pleistocene. The owners of the skulls were good hunters, capable of fashioning stone blades from quartz. Ancient bones of horses and cattle, as well as extinct woolly rhinoceros and giant deer, were found strewn near the skull remains. Researchers from the Chinese Academy of Sciences in Beijing and at Washington University in St. Louis described the skulls as having a “mosaic” of features. Writing Thursday in the journal Science, they noted similarities with three groups: The brow ridges of the skulls were modest and the skull bone mass was reduced, like features of early modern humans living in the Old World. The skulls had a broad and flat brainpan, like other eastern Eurasian humans from the mid-Pleistocene epoch. Their semicircular ear canals and the enlarged section at the back of the skull, however, were like a Neanderthal’s. “Eastern Asian late archaic humans have been interpreted to resemble their Neanderthal contemporaries to some degree,” Xiujie Wu, an author of the study at the Chinese Academy of Sciences‘ Institute of Vertebrate Paleontology and Paleoanthropology, said in a statement. “Yet it is only with the discovery of two human crania,” she said, “that the nature of these eastern Eurasian early Late Pleistocene archaic humans is becoming clear.” The large brains of these archaic humans ruled out Homo erectus and other known hominid species, the scientists wrote. The researchers were vague about what they thought the species might be, describing them only as archaic humans. But Wu told Science Magazine that the fossils could represent “a kind of unknown or new archaic human that survived on in East Asia to 100,000 years ago.” Other experts speculated that these skull caps could represent a little-known human relative: the mysterious Denisovans, a species that currently exists only as sequenced DNA taken from finger bone and a tooth found in a Siberian cave. Thought to live some 100,000 to 50,000 years ago, the Denisovans shared genetic material with humans as well as Neanderthals. A 2015 analysis of the specimen scraps indicated that the Denisovans lived for some 60,000 years side-by-side with Neanderthals and humans in Asia. (That humans interbred with Neanderthals is, of course, old news. Many humans who have Eurasian ancestry carry bits of Neanderthal DNA, around 2 to 5 percent of it, within their genes. In the process of swapping DNA, Neanderthals lent us genes for bad skin while boosting our immune responses.) The cranial remains “show an intriguing combination of Neanderthal-like as well as archaic features,” Harvati said. “This would be the combination that one would expect based on the ancient DNA analysis of Denisovans, who were closely related to Neanderthals.” The paper did not mention Denisovans, the study authors said, because DNA extraction attempts failed to yield genetic material. But the lack of even a nod toward the Denisovans in the new report was a point that Philipp Gunz, an evolutionary anthropologist at the Max Planck Institute in Leipzig, found surprising. The fossils, which Gunz called “remarkable,” as he told The Post, “certainly look like what many paleoanthropologists (myself included) imagine the Denisovans to look like.” Time may tell — if scientists can pull off a successful laboratory analysis. “Unfortunately, however, it is not possible to infer skull morphology from ancient DNA directly,” Gunz said. “I therefore hope that future studies will be able to extract ancient DNA from these or similar specimens.”
Ben Guarino
March 3, 2017
Skulls found in China were part modern human, part Neanderthal; possibly new species
Modern humans outlasted the Neanderthals by about 40,000 years and counting. But don’t pat yourself on the back too firmly for outliving those troglodytes. Neanderthals crafted tools and tamed fire. They cared for their dead. Animal horns and blackened fire pits encircling the remains of a Neanderthal toddler suggest a 42,000-year-old funeral rite. If a Neanderthal indeed wore a talon necklace, as a collection of polished eagle claws indicate, they beat us to jewelry, too. Perhaps one of your ancient ancestors found the claw necklaces sexy: Some scientists theorize humans gave Neanderthals genital herpes and tapeworm parasites. Their proportions, however, remained distinctly Neanderthal. Neanderthal bodies were shorter and stockier, more Gimli son of Gloin than Gigi Hadid. Their skulls were built differently, too, with a few features — like heavy brow ridges — particularly unlike ours. Which makes a pair of newly described skulls something of a wonder. The partial skulls have features up to this time unseen in the hominid fossil record, sharing both human and Neanderthal characteristics. “It is a very exciting discovery,” as Katerina Harvati, an expert in Neanderthal evolution at the University of Tübingen in Germany, who was not involved with the research, told The Washington Post. “Especially because the human fossil record from East Asia has been not only fragmentary but also difficult to date.” Excavators dug up the skull cap fragments in 2007 and 2014, in Lingjing, located in China’s Henan province. The diggers discovered two partial skulls in a site thought to be inhabited 105,000 to 125,000 years ago, during an epoch called the Pleistocene. The owners of the skulls were good hunters, capable of fashioning stone blades from quartz. Ancient bones of horses and cattle, as well as extinct woolly rhinoceros and giant deer, were found strewn near the skull remains. Researchers from the Chinese Academy of Sciences in Beijing and at Washington University in St. Louis described the skulls as having a “mosaic” of features. Writing Thursday in the journal Science, they noted similarities with three groups: The brow ridges of the skulls were modest and the skull bone mass was reduced, like features of early modern humans living in the Old World. The skulls had a broad and flat brainpan, like other eastern Eurasian humans from the mid-Pleistocene epoch. Their semicircular ear canals and the enlarged section at the back of the skull, however, were like a Neanderthal’s. “Eastern Asian late archaic humans have been interpreted to resemble their Neanderthal contemporaries to some degree,” Xiujie Wu, an author of the study at the Chinese Academy of Sciences‘ Institute of Vertebrate Paleontology and Paleoanthropology, said in a statement. “Yet it is only with the discovery of two human crania,” she said, “that the nature of these eastern Eurasian early Late Pleistocene archaic humans is becoming clear.” The large brains of these archaic humans ruled out Homo erectus and other known hominid species, the scientists wrote. The researchers were vague about what they thought the species might be, describing them only as archaic humans. But Wu told Science Magazine that the fossils could represent “a kind of unknown or new archaic human that survived on in East Asia to 100,000 years ago.” Other experts speculated that these skull caps could represent a little-known human relative: the mysterious Denisovans, a species that currently exists only as sequenced DNA taken from finger bone and a tooth found in a Siberian cave. Thought to live some 100,000 to 50,000 years ago, the Denisovans shared genetic material with humans as well as Neanderthals. A 2015 analysis of the specimen scraps indicated that the Denisovans lived for some 60,000 years side-by-side with Neanderthals and humans in Asia. (That humans interbred with Neanderthals is, of course, old news. Many humans who have Eurasian ancestry carry bits of Neanderthal DNA, around 2 to 5 percent of it, within their genes. In the process of swapping DNA, Neanderthals lent us genes for bad skin while boosting our immune responses.) The cranial remains “show an intriguing combination of Neanderthal-like as well as archaic features,” Harvati said. “This would be the combination that one would expect based on the ancient DNA analysis of Denisovans, who were closely related to Neanderthals.” The paper did not mention Denisovans, the study authors said, because DNA extraction attempts failed to yield genetic material. But the lack of even a nod toward the Denisovans in the new report was a point that Philipp Gunz, an evolutionary anthropologist at the Max Planck Institute in Leipzig, found surprising. The fossils, which Gunz called “remarkable,” as he told The Post, “certainly look like what many paleoanthropologists (myself included) imagine the Denisovans to look like.” Time may tell — if scientists can pull off a successful laboratory analysis. “Unfortunately, however, it is not possible to infer skull morphology from ancient DNA directly,” Gunz said. “I therefore hope that future studies will be able to extract ancient DNA from these or similar specimens.”
Sunday, May 17, 2015
Oldest Stone Bracelet Yet Found - 40,000 Year Old Denisovan (?)Writing in the Novosibirsk magazine, Science First Hand, Dr Derevyanko said: 'There were found two fragments of the bracelet of a width of 2.7cm and a thickness of 0.9 cm. The estimated diameter of the find was 7cm. Near one of the cracks was a drilled hole with a diameter of about 0.8 cm. Studying them, scientists found out that the speed of rotation of the drill was rather high, fluctuations minimal, and that was there was applied drilling with an implement - technology that is common for more recent times.Writing in the Novosibirsk magazine, Science First Hand, Dr Derevyanko said: 'There were found two fragments of the bracelet of a width of 2.7cm and a thickness of 0.9 cm. The estimated diameter of the find was 7cm. Near one of the cracks was a drilled hole with a diameter of about 0.8 cm. Studying them, scientists found out that the speed of rotation of the drill was rather high, fluctuations minimal, and that was there was applied drilling with an implement - technology that is common for more recent times. Discovery
Oh, those mysterious Denisovans. Check out this latest:
Story and many photographs of the wonderful bracelet from The Siberian Times online:
Story and many photographs of the wonderful bracelet from The Siberian Times online:
Stone bracelet is oldest ever found in the world
By Anna Liesowska
Tuesday, November 19, 2013
New "Archaic" Mystery Humans Uncovered in Latest DNA Genome Sequencing
Heh heh heh :) I love this!
From Nature Magazine Online:
From Nature Magazine Online:
Mystery humans spiced up ancients’ rampant sex lives
Genome analysis suggests interbreeding between modern humans, Neanderthals, Denisovans and a mysterious archaic population.
Sunday, September 9, 2012
More on the Deciphering of DNA of Denisovan - Girl!
From BBC News - always so well written!
31 August 2012 Last updated at 02:17 ET
31 August 2012 Last updated at 02:17 ET
DNA of girl from Denisova cave gives up genetic secrets
Sunday, September 2, 2012
Denisovan Genome Deciphered!
Article at Popular Archaeology:
Archaic Human DNA Reveals its Secrets
Recently completed research has revealed the complete sequence of the Denisovan genome, the DNA "blueprint" or strands that describe the makeup of a new species of archaic human, fossils of which were first recovered in March, 2010 in a cave in southern Siberia*.
Although the available evidence for testing was slim -- the Denisovan finds have consisted only of a finger bone fragment and two teeth (the test sample itself was derived from the finger bone fragment) -- the researchers were able to develop a means to "unzip" the DNA such that its two strands could be used to generate new molecules for sequencing, permitting the team to determine a very complete genome sequence much like what can be obtained for a modern human genome. [So, basically, they made it up?] They then compared the genome with genomes of modern humans from around the world.
Among the study results, the researchers found that the Denisovans share more genes with individuals from Papua New Guinea than any other population, and that more Denisovan alleles were common with those of Asian and South American populations than European populations. The study authors suggest that the latter reflects interbreeding between modern humans and the Neandertals, who are also related to Neanderthals, rather than direct gene flow from the Denisovans. [What?] In addition, the study reports several other findings: One, that the Denisovan genome contained alleles that correspond to alleles in present-day humans that are associated with dark skin, brown hair and brown eyes; two, that there were a number of genetic changes in modern humans that occurred after the split from the Denisovans; and three, that Denisovan genetic diversity was extremely low, due, they suggest, to a small initial population that grew quickly, without time for genetic diversity to increase to any substantial degree. Along this vain, the authors suggest that if further research shows that the Neanderthal population size changed over time in a similar way, it could mean that a single population expanding out of Africa gave rise to both the Denisovans and Neandertals.
In conclusion, the study team remarks on the general implications of the research results for future endeavors. Reports M. Meyer, et. al.:
[1] "A High-Coverage Genome Sequence from an Archaic Denisovan Individual," by M. Meyer; M. Kircher; M.-T. Gansauge; F. Racimo; K. Prüfer; C. de Filippo; Q. Fu; M. Siebauer; U. Stenzel; J. Dabney; A.M. Andrés; J. Kelso; S. Pääbo at Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. For a complete list of authors, please see the manuscript.
VAIN? Are you kidding me? Are there no longer people who know the difference between VEIN and VAIN? Holy Goddess!
Although the available evidence for testing was slim -- the Denisovan finds have consisted only of a finger bone fragment and two teeth (the test sample itself was derived from the finger bone fragment) -- the researchers were able to develop a means to "unzip" the DNA such that its two strands could be used to generate new molecules for sequencing, permitting the team to determine a very complete genome sequence much like what can be obtained for a modern human genome. [So, basically, they made it up?] They then compared the genome with genomes of modern humans from around the world.
Among the study results, the researchers found that the Denisovans share more genes with individuals from Papua New Guinea than any other population, and that more Denisovan alleles were common with those of Asian and South American populations than European populations. The study authors suggest that the latter reflects interbreeding between modern humans and the Neandertals, who are also related to Neanderthals, rather than direct gene flow from the Denisovans. [What?] In addition, the study reports several other findings: One, that the Denisovan genome contained alleles that correspond to alleles in present-day humans that are associated with dark skin, brown hair and brown eyes; two, that there were a number of genetic changes in modern humans that occurred after the split from the Denisovans; and three, that Denisovan genetic diversity was extremely low, due, they suggest, to a small initial population that grew quickly, without time for genetic diversity to increase to any substantial degree. Along this vain, the authors suggest that if further research shows that the Neanderthal population size changed over time in a similar way, it could mean that a single population expanding out of Africa gave rise to both the Denisovans and Neandertals.
In conclusion, the study team remarks on the general implications of the research results for future endeavors. Reports M. Meyer, et. al.:
By providing a comprehensive catalog of features that became fixed in modern humans after their separation from their closest archaic relatives, this work will eventually lead to a better understanding of the biological differences that existed between the groups. This should ultimately aid in determining how it was that modern humans came to expand dramatically in population size as well as cultural complexity while archaic humans eventually dwindled in numbers and became physically extinct. [1]* In March 2010, scientists announced the discovery of a finger bone fragment of a juvenile female that lived about 41,000 years ago, found in the remote Denisova Cave in the Altai mountains in Siberia, a region also inhabited at about the same time by Neanderthals and perhaps modern humans. Two other bone specimens belonging to different members of the same population have since been found.
[1] "A High-Coverage Genome Sequence from an Archaic Denisovan Individual," by M. Meyer; M. Kircher; M.-T. Gansauge; F. Racimo; K. Prüfer; C. de Filippo; Q. Fu; M. Siebauer; U. Stenzel; J. Dabney; A.M. Andrés; J. Kelso; S. Pääbo at Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. For a complete list of authors, please see the manuscript.
******************************
VAIN? Are you kidding me? Are there no longer people who know the difference between VEIN and VAIN? Holy Goddess!
Sunday, February 5, 2012
Where We Came From
The New York Times has put together a clear synopsis of the most recent research and findings regarding who WE are and where WE came from:
DNA Turning Human Story Into a Tell-All
By ALANNA MITCHEL
The tip of a girl’s 40,000-year-old pinky finger found in a cold Siberian cave, paired with faster and cheaper genetic sequencing technology, is helping scientists draw a surprisingly complex new picture of human origins.
The new view is fast supplanting the traditional idea that modern humans triumphantly marched out of Africa about 50,000 years ago, replacing all other types that had gone before.
Instead, the genetic analysis shows, modern humans encountered and bred with at least two groups of ancient humans in relatively recent times: the Neanderthals, who lived in Europe and Asia, dying out roughly 30,000 years ago, and a mysterious group known as the Denisovans, who lived in Asia and most likely vanished around the same time.
Their DNA lives on in us even though they are extinct. “In a sense, we are a hybrid species,” Chris Stringer, a paleoanthropologist who is the research leader in human origins at the Natural History Museum in London, said in an interview.
The Denisovans (pronounced dun-EE-suh-vinz) were first described a year ago in a groundbreaking paper in the journal Nature made possible by genetic sequencing of the girl’s pinky bone and of an oddly shaped molar from a young adult.
Those findings have unleashed a spate of new analyses.
Scientists are trying to envision the ancient couplings and their consequences: when and where they took place, how they happened, how many produced offspring and what effect the archaic genes have on humans today.
Other scientists are trying to learn more about the Denisovans: who they were, where they lived and how they became extinct.
A revolutionary increase in the speed and a decline in the cost of gene-sequencing technology have enabled scientists at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, to map the genomes of both the Neanderthals and the Denisovans.
Comparing genomes, scientists concluded that today’s humans outside Africa carry an average of 2.5 percent Neanderthal DNA, and that people from parts of Oceania also carry about 5 percent Denisovan DNA. A study published in November found that Southeast Asians carry about 1 percent Denisovan DNA in addition to their Neanderthal genes. It is unclear whether Denisovans and Neanderthals also interbred.
A third group of extinct humans, Homo floresiensis, nicknamed “the hobbits” because they were so small, also walked the earth until about 17,000 years ago. It is not known whether modern humans bred with them because the hot, humid climate of the Indonesian island of Flores, where their remains were found, impairs the preservation of DNA.
This means that our modern era, since H. floresiensis died out, is the only time in the four-million-year human history that just one type of human has been alive, said David Reich, a geneticist at Harvard Medical School who was the lead author of the Nature paper on the Denisovans.
For many scientists, the epicenter of the emerging story on human origins is the Denisova cave in the Altai Mountains of Siberia, where the girl’s finger bone was discovered. It is the only known place on the planet where three types of humans — Denisovan, Neanderthal and modern — lived, probably not all at once.
John Hawks, a paleoanthropologist at the University of Wisconsin-Madison, whose lab is examining the archaic genomes, visited the cave in July. It has a high arched roof like a Gothic cathedral and a chimney to the sky, he said, adding that being there was like walking in the footsteps of our ancestors.
The cave has been open to the elements for a quarter of a million years and is rich with layers of sediments that may contain other surprises. Some of its chambers are unexplored, and excavators are still finding human remains that are not yet identified. The average temperature for a year, 32 degrees Fahrenheit, bodes well for the preservation of archaic DNA.
Could this cave have been one of the spots where the ancient mating took place? Dr. Hawks said it was possible.
But Dr. Reich and his team have determined through the patterns of archaic DNA replications that a small number of half-Neanderthal, half-modern human hybrids walked the earth between 46,000 and 67,000 years ago, he said in an interview. The half-Denisovan, half-modern humans that contributed to our DNA were more recent.
And Peter Parham, an immunologist at the Stanford University School of Medicine, has used an analysis of modern and ancient immune-system genetic components — alleles — to figure out that one of the Denisovan-modern couplings most likely took place in what is now southeastern China.
He has also found some evidence that a Neanderthal-modern pair mated in west Asia.
He stressed, however, that his study was just the first step in trying to reconstruct where the mating took place.
Dr. Parham’s analysis, which shows that some archaic immune alleles are widespread among modern humans, concludes that as few as six couplings all those tens of thousands of years ago might have led to the current level of ancient immune alleles.
Another paper, by Mathias Currat and Laurent Excoffier, two Swiss geneticists, suggests that breeding between Neanderthals and modern humans was rare. Otherwise, they say, modern humans would have far more Neanderthal DNA.
Were they romantic couplings? More likely they were aggressive acts between competing human groups, Dr. Stringer said. For a model, he pointed to modern hunter-gatherer groups that display aggressive behavior among tribes. [Of course! Leave it to a modern "human" male to proclaim that it was all about rape and nothing but rape, rape, rape. Not a smidgeon of evidence to support his claim, but when did that ever stop an Establishment scientist from proclaiming something as Gospel Truth? Just remember the tale of the unfaithful mares that I've posted about before to show how such narrow-minded views of "accepted truth" can blow up in the Establishment's face!]
When modern humans mated with them, they got an injection of helpful genetic immune material, so useful that it remains in the genome today. This suggests that modern humans needed the archaic DNA to survive.
The downside of archaic immune material is that it may be responsible for autoimmune diseases like diabetes, arthritis and multiple sclerosis, Dr. Parham said, stressing that these are preliminary results.
Dr. Reich and others suggest that the interbreeding that led to this phenomenon probably occurred in the south, rather than in Siberia. If so, the Denisovans were more widely dispersed than Neanderthals, and possibly more successful. [What nonsense! So-called Neanderthal and so-called Denisovans continue to live - within us - today. You know, you can't have the theory of "evolution" both ways. Just because hairy wide-browed red-heads with big noses aren't supposedly walking around among us today does not mean the species was not "successful." And are we really so sure such people aren't walking around among us today? Just take a look around!]
But the questions of how many Denisovans there were and how they became extinct have yet to be answered. Right now, as Dr. Reich put it, they are “a genome in search of an archaeology.”
Yeah, isn't it interesting how scientists are now trying to redefine the term "extinct" without coming right out and saying so? If so-called "Denisovan" man was extinct, how come at least 5% of all human beings alive on the earth today carry Denisovan DNA? It's not possible for them to be called "extinct" under such a circumstance! The same applies to the so-called "Neanderthals." What a lot of bull shit these people are dishing out.
The full story of humankind has yet to be told, and there are still dudes running around trying to find the "missing link" when each DNA study makes it clearer and clearer that there were humans, and there were simians. Simians and humans cannot breed. Humans breed with other humans.
I wonder what they'll be dishing out to us 30 years from now? Remember, so-called experts of the day were once absolutely fooled by "Piltdown Man." Check out this article from The Guardian, complete with references to "early apemen." Geez!
 |
| A view from a cave! Wow - spectacular! Photo by Johannes Krause
EARLY LAIR A view above the Denisova
cave, where clues to prehistoric interbreeding
were found. Faster technology is aiding research
|
The new view is fast supplanting the traditional idea that modern humans triumphantly marched out of Africa about 50,000 years ago, replacing all other types that had gone before.
Instead, the genetic analysis shows, modern humans encountered and bred with at least two groups of ancient humans in relatively recent times: the Neanderthals, who lived in Europe and Asia, dying out roughly 30,000 years ago, and a mysterious group known as the Denisovans, who lived in Asia and most likely vanished around the same time.
Their DNA lives on in us even though they are extinct. “In a sense, we are a hybrid species,” Chris Stringer, a paleoanthropologist who is the research leader in human origins at the Natural History Museum in London, said in an interview.
The Denisovans (pronounced dun-EE-suh-vinz) were first described a year ago in a groundbreaking paper in the journal Nature made possible by genetic sequencing of the girl’s pinky bone and of an oddly shaped molar from a young adult.
Those findings have unleashed a spate of new analyses.
Scientists are trying to envision the ancient couplings and their consequences: when and where they took place, how they happened, how many produced offspring and what effect the archaic genes have on humans today.
Other scientists are trying to learn more about the Denisovans: who they were, where they lived and how they became extinct.
A revolutionary increase in the speed and a decline in the cost of gene-sequencing technology have enabled scientists at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, to map the genomes of both the Neanderthals and the Denisovans.
Comparing genomes, scientists concluded that today’s humans outside Africa carry an average of 2.5 percent Neanderthal DNA, and that people from parts of Oceania also carry about 5 percent Denisovan DNA. A study published in November found that Southeast Asians carry about 1 percent Denisovan DNA in addition to their Neanderthal genes. It is unclear whether Denisovans and Neanderthals also interbred.
A third group of extinct humans, Homo floresiensis, nicknamed “the hobbits” because they were so small, also walked the earth until about 17,000 years ago. It is not known whether modern humans bred with them because the hot, humid climate of the Indonesian island of Flores, where their remains were found, impairs the preservation of DNA.
This means that our modern era, since H. floresiensis died out, is the only time in the four-million-year human history that just one type of human has been alive, said David Reich, a geneticist at Harvard Medical School who was the lead author of the Nature paper on the Denisovans.
For many scientists, the epicenter of the emerging story on human origins is the Denisova cave in the Altai Mountains of Siberia, where the girl’s finger bone was discovered. It is the only known place on the planet where three types of humans — Denisovan, Neanderthal and modern — lived, probably not all at once.
John Hawks, a paleoanthropologist at the University of Wisconsin-Madison, whose lab is examining the archaic genomes, visited the cave in July. It has a high arched roof like a Gothic cathedral and a chimney to the sky, he said, adding that being there was like walking in the footsteps of our ancestors.
The cave has been open to the elements for a quarter of a million years and is rich with layers of sediments that may contain other surprises. Some of its chambers are unexplored, and excavators are still finding human remains that are not yet identified. The average temperature for a year, 32 degrees Fahrenheit, bodes well for the preservation of archaic DNA.
Could this cave have been one of the spots where the ancient mating took place? Dr. Hawks said it was possible.
But Dr. Reich and his team have determined through the patterns of archaic DNA replications that a small number of half-Neanderthal, half-modern human hybrids walked the earth between 46,000 and 67,000 years ago, he said in an interview. The half-Denisovan, half-modern humans that contributed to our DNA were more recent.
And Peter Parham, an immunologist at the Stanford University School of Medicine, has used an analysis of modern and ancient immune-system genetic components — alleles — to figure out that one of the Denisovan-modern couplings most likely took place in what is now southeastern China.
He has also found some evidence that a Neanderthal-modern pair mated in west Asia.
He stressed, however, that his study was just the first step in trying to reconstruct where the mating took place.
Dr. Parham’s analysis, which shows that some archaic immune alleles are widespread among modern humans, concludes that as few as six couplings all those tens of thousands of years ago might have led to the current level of ancient immune alleles.
Another paper, by Mathias Currat and Laurent Excoffier, two Swiss geneticists, suggests that breeding between Neanderthals and modern humans was rare. Otherwise, they say, modern humans would have far more Neanderthal DNA.
Were they romantic couplings? More likely they were aggressive acts between competing human groups, Dr. Stringer said. For a model, he pointed to modern hunter-gatherer groups that display aggressive behavior among tribes. [Of course! Leave it to a modern "human" male to proclaim that it was all about rape and nothing but rape, rape, rape. Not a smidgeon of evidence to support his claim, but when did that ever stop an Establishment scientist from proclaiming something as Gospel Truth? Just remember the tale of the unfaithful mares that I've posted about before to show how such narrow-minded views of "accepted truth" can blow up in the Establishment's face!]
The value of the interbreeding shows up in the immune system, Dr. Parham’s analysis suggests. The Neanderthals and Denisovans had lived in Europe and Asia for many thousands of years before modern humans showed up and had developed ways to fight the diseases there, he said in an interview.
When modern humans mated with them, they got an injection of helpful genetic immune material, so useful that it remains in the genome today. This suggests that modern humans needed the archaic DNA to survive.
The downside of archaic immune material is that it may be responsible for autoimmune diseases like diabetes, arthritis and multiple sclerosis, Dr. Parham said, stressing that these are preliminary results.
Although little is known about the Denisovans — the only remains so far are the pinky bone and the tooth, and there are no artifacts like tools. Dr. Reich and others suggest that they were once scattered widely across Asia, from the cold northern cave to the tropical south. The evidence is that modern populations in Oceania, including aboriginal Australians, carry Denisovan genes.
Dr. Reich and others suggest that the interbreeding that led to this phenomenon probably occurred in the south, rather than in Siberia. If so, the Denisovans were more widely dispersed than Neanderthals, and possibly more successful. [What nonsense! So-called Neanderthal and so-called Denisovans continue to live - within us - today. You know, you can't have the theory of "evolution" both ways. Just because hairy wide-browed red-heads with big noses aren't supposedly walking around among us today does not mean the species was not "successful." And are we really so sure such people aren't walking around among us today? Just take a look around!]
But the questions of how many Denisovans there were and how they became extinct have yet to be answered. Right now, as Dr. Reich put it, they are “a genome in search of an archaeology.”
Yeah, isn't it interesting how scientists are now trying to redefine the term "extinct" without coming right out and saying so? If so-called "Denisovan" man was extinct, how come at least 5% of all human beings alive on the earth today carry Denisovan DNA? It's not possible for them to be called "extinct" under such a circumstance! The same applies to the so-called "Neanderthals." What a lot of bull shit these people are dishing out.
The full story of humankind has yet to be told, and there are still dudes running around trying to find the "missing link" when each DNA study makes it clearer and clearer that there were humans, and there were simians. Simians and humans cannot breed. Humans breed with other humans.
I wonder what they'll be dishing out to us 30 years from now? Remember, so-called experts of the day were once absolutely fooled by "Piltdown Man." Check out this article from The Guardian, complete with references to "early apemen." Geez!
Sunday, August 14, 2011
Challenges to the "Out of Africa" Theory of Human Evolution/Migration Continue
Here's the lastest in the ongoing battle:
from bloomberg.com
Caveman Zezva’s 1.8-Million-Year Grin Forces Rewrite of History
By Helena Bedwell - Aug 8, 2011 6:00 PM CT
from bloomberg.com
Caveman Zezva’s 1.8-Million-Year Grin Forces Rewrite of History
By Helena Bedwell - Aug 8, 2011 6:00 PM CT
The history of human evolution needs to be rewritten.
This is the view of David Lordkipanidze, who claims his discovery of the bones of a couple known as Zezva and Mzia puts the Black Sea country of Georgia at the center of the archaeological world.
The small-brained apelike creatures lived in the area at least 1.75 million years ago, making them the first proven residents of Europe and Asia, says Lordkipanidze. The find has thrown into question the theory that the first hominids to disperse from Africa were homo erectus, a species with large brains and bodies approaching human size.
“Now the news is that we have found stone tools,” says Lordkipanidze, the Georgian National Museum’s director. “Stone and bone samples are older than any other findings, proving we’ve had human presence in Georgia from at least 1.85 million years or more.”
The 49-year-old professor remains calm about the discovery, sitting in his office wearing a blue shirt and denims. The news is supported by 10 experts who have written a report to the National Academy of Science, he says. Lordkipanidze is also dismissive of skeptics who say the announcement is only intended to help Georgia to become a bigger tourist destination and global hub for archaeology.
The nation of 4.6 million people on the Silk Road has been trying to restore its economy after it fought a five-day war in 2008 over the breakaway Georgian region of South Ossetia. The Georgian government forecasts as many as 3 million tourist visits this year, rising to 5 million by 2015.
Human Jaw
Lordkipanidze’s room is bright and modest. Shelves are full of memorabilia of the findings from near the village of Dmanisi, southwest of the capital Tbilisi and near the Armenian border.
An international team found the first human jaw there in 1991. Between then and 2007, fossils from as many as six individuals have been found at the same site. Three are being reconstructed by artists -- Zezva and Mzia (typical old- fashioned Georgian names) and their possible offspring of a teenage female. The skulls can be covered with flesh and hair to give them simian smiles and protruding jaws. The excavations are funded by Georgia’s government and companies including BP Plc and Rolex Group.
National Geographic magazine, and Science, have both put Zezva and Mzia on their covers, noting that they hold the key to human evolution. Perhaps early humans took a detour into Eurasia before an epic journey out of Africa.
“Dmanisi humans are either the first representatives of homo erectus,” says Lordkipanidze. “Or ancestors of homo erectus.”
Tiger Skulls
These people were about 1.4 meters (4 feet 9 inches) tall, with small brains and legs more developed than their arms, showing that they were good runners. They lived alongside predators like saber-toothed tigers, whose skulls were also found.
“Their main lifestyle was to compete with big and dangerous animals,” Lordkipanidze says. “They lived in groups and they were taking care of each other.” They were on a site totaling no more than 10 square meters and their death was mostly natural.
Lordkipanidze’s museum’s collection dates back to 1852. After the Rose revolution in 2003, it was re-established the following year by a presidential decree. It unifies the Soviet Occupation Museum, the archives of the Ministry of State Security and Internal Affairs of Georgia, and the golden treasury, including objects from the ancient kingdom of Colchis from Vani, known as the destination of Jason and the Argonauts in their quest for the Golden Fleece.
Excavations continue at Dmanisi, while only 10 percent of the historical site has been explored, Lordkipanidze says.
“The world should know that we are preserving a world heritage, not just ours,” Lordkipanidze says. “It’s highly educational and has huge tourism potential.”
Information: http://www.museum.ge/web_page/
And this - not exactly related but it only goes to show that we have a lot yet to learn about what happened 50,000 to 40,000 years ago, let alone a couple of million years ago!
From newscientist.com
Stone Age toe could redraw human family tree
10 August 2011 by Colin Barras
Magazine issue 2825.
ON THE western fringes of Siberia, the Stone Age Denisova cave has surrendered precious treasure: a toe bone that could shed light on early humans' promiscuous relations with their hominin cousins.
New Scientist has learned that the bone is now in the care of Svante Pääbo at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, who revealed the first genetic evidence of interbreeding between ancient humans and other hominins (New Scientist, 30 July, p 34).
There are tantalising hints that the find strengthens the case for a third major group of hominins circulating in Eurasia at the same time as early humans and the Neanderthals. It might possibly even prove all three groups were interbreeding (see diagram).
The Denisova cave had already yielded a fossil tooth and finger bone, in 2000 and 2008. Last year, Pääbo's DNA analysis suggested both belonged to a previously unknown group of hominins, the Denisovans. The new bone, an extremely rare find, looks likely to belong to the same group.
It is a very exciting discovery, says Isabelle De Groote at London's Natural History Museum. "Hominin material from southern Siberia is rare and usually extremely fragmentary."
The primitive morphology of the 30,000 to 50,000-year-old Denisovan finger bone and tooth indicates that Denisovans separated from the Neanderthals roughly 300,000 years ago. At the time of the analysis, Pääbo speculated that they came to occupy large parts of east Asia at a time when Europe and western Asia were dominated by Neanderthals. By 40,000 years ago, Homo sapiens was also moving around much of the region. But the Denisovans remain known only from the finger and tooth fossils - not enough information to formally assign them to their own species.
That may change with analysis of the newly discovered toe bone. It was found in the same layer of the cave floor as the finger bone, by Maria Mednikova at the Russian Academy of Sciences in Moscow (Archaeology, Ethnology and Anthropology of Eurasia, vol 39, p 129).
Mednikova says this suggests it belonged to a contemporary individual, alive roughly 40,000 years ago. But her studies show the finger and toe bones belonged to distinct people. In addition, the toe bone is stocky and its shape is somewhere between that of a modern human and a typical Neanderthal.
Others are less convinced. Erik Trinkaus at Washington University in St Louis, Missouri, who has written extensively on hominin foot bone morphology, says the bone's sturdy appearance is interesting but inconclusive from a taxonomic perspective.
What's needed is DNA evidence. For now, though, Pääbo's team remain very tight-lipped about what, if anything, they have found. "We have no results we are ready to talk about yet," Pääbo told New Scientist. Mednikova saw some of the team's preliminary findings last month and promises a "wonderful result" will be published in the near future - although with the analysis still under review she can say no more.
Her enthusiasm suggests that Pääbo's team has successfully extracted DNA from the toe bone, and hints that it shows that this was no ordinary hominin. At the very least, one can presume it doesn't belong to a human or a Neanderthal.
"The Neanderthals came to the Altai mountains [in Siberia] about 45,000 years ago and were probably assimilated by the native Denisovan population," she says. "It cannot be excluded that the individual was Denisovan, Neanderthal or even a hybrid - why not?"
If the Stone Age toe really did belong to a Neanderthal-Denisovan hybrid, it would be a remarkable find. Pääbo is fast building a reputation for revealing Homo sapiens' promiscuous past. He has shown that humans and Neanderthals interbred, as did humans and Denisovans. Until the latest analysis is published, we can only speculate on what has been found. But the human family tree could be about to get even more complicated. If so, there may be a case for reclassifying all three as members of the same species.
Tuesday, June 21, 2011
Not Cannibals After All?
This story certainly presents a different take on this discovery - I'm sure I read about it a few months ago and then it was being said the marks on the human bones were evidence of butchering. Now, the careful term defleshing is being used. Well, as much as I hate to think that humans ate other humans, we certainly know that happened, so why not back then, too? Does that make us sound too uncivilized, certainly a lot less civilized than the so-called Neanderthals?
20 June 2011 Last updated at 19:22 ET
Early human fossils unearthed in Ukraine
By Jennifer Carpenter
Science reporter, BBC News
Ancient remains uncovered in Ukraine represent some of the oldest evidence of modern people in Europe, experts have claimed.
Archaeologists found human bones and teeth, tools, ivory ornaments and animal remains at the Buran-Kaya cave site.
The 32,000-year-old fossils bear cut marks suggesting they were defleshed as part of a post-mortem ritual.
Details have been published in the journal PLoS One.
Archaeologist Dr Alexander Yanevich from the National Ukrainian Academy of Science in Kiev discovered the four Buran-Kaya caves in the Crimean mountains in 1991.
Since then, roughly two hundred human bone fragments have been unearthed at the site. Among the shards of human bones and teeth, archaeologists have found ornaments fashioned from ivory, along with the abundant remains of animals.
The artefacts made by humans at the site allowed archaeologists to tie the ancient people to a cultural tradition known as the Gravettian. This culture came to span the entire European continent and is named after the site of La Gravette in France, where this stone age culture was first studied.
Researchers were able to directly date the human fossils using radiocarbon techniques. The shape and form of the remains told the scientists they were dealing with modern humans (Homo sapiens sapiens).
Eastern promise
One thing that intrigued researchers was the scarcity of human long bones (bones from the limbs) in the caves.
The site yielded countless limb bones from antelope, foxes and hares.
But the human remains consisted of vertebrae, teeth and skull bones no larger than 12cm. What is more, the positions of cut marks found on the human fragments were distinct from those found on the animal bones.
And while the bone marrow had been removed from butchered animals, it had been left alone in the case of the human remains at the site, explained co-author Sandrine Prat from the French National Centre for Scientific Research (CNRS) in Paris. She suspects this demonstrates that human bones were processed differently from those of animals. Human flesh was removed as part of ritual "cleaning", not to be eaten.
Defining culture
The finds offer anthropologists a glimpse into a very early and important human culture, said Professor Clive Finlayson, an evolutionary ecologist and director of the Gibraltar Museum.
"Gravettian culture is the culture that defines modern humans. These people had knives, lightweight tools, open air camps, they used mammoth bones to make tents," he said, adding that this was the earliest example of the Gravettian cultural tradition.
Professor Finlayson said that uncovering evidence of this culture in Ukraine gave weight to the idea that early modern people spread into Europe from the Russian plains, not north through the Balkans from the Middle East.
"What has excited me is that we have found evidence of humans where I would expect them to be, exploiting foods that I would expect them to be exploiting," Professor Finlayson told BBC News.
So, perhaps humans were eating each other 32,000 years ago - or not. The jury is definitely still out on this one. Just because the marrow wasn't removed from the human bones doesn't mean the flesh wasn't consumed. Perhaps there was some big tribal ataboo about eating human bone marrow. We just don't know - and probably will never know.
Still not explained - how Homo Sapiens Sapiens, Homo Neanderthalis and Homo Denisovan could breed with each other and produce viable human beings that evidently also were able to produce offspring, enough at any rate, that some genes of both Neanderthal and Denisovan are found in modern human populations. (This was reported at New Science on June 16, 2010, Breeding with Neanderthals helped humans go global). Do you see the bias implicit in that article's title? As if Neanderthals were something less than fully human! Har!
Some people would have us believe that modern humans and the chimpanzee are like 99.98% related. Fine - so their DNA may share many similarities. Yet, humans cannot breed with chimpanzees, or great apes, or bonopos, etc. etc. Let's face it, there is a fundamental, unbridgeable difference between a human being and not-human ape-like being, and never the twain shall meet, not 2 million, 1 million, 100,000 or 10,000 years ago, and not 10,000, 100,000, 1 million or 2 million years from now. Neanderthals and Denisovans were fully human, and they bred with other humans. Their descendants walk among us today, and we know it now, for certain, because some of their unique DNA sequences survived in today's human population.
20 June 2011 Last updated at 19:22 ET
Early human fossils unearthed in Ukraine
By Jennifer Carpenter
Science reporter, BBC News
Ancient remains uncovered in Ukraine represent some of the oldest evidence of modern people in Europe, experts have claimed.
Archaeologists found human bones and teeth, tools, ivory ornaments and animal remains at the Buran-Kaya cave site.
The 32,000-year-old fossils bear cut marks suggesting they were defleshed as part of a post-mortem ritual.
Details have been published in the journal PLoS One.
Archaeologist Dr Alexander Yanevich from the National Ukrainian Academy of Science in Kiev discovered the four Buran-Kaya caves in the Crimean mountains in 1991.
Since then, roughly two hundred human bone fragments have been unearthed at the site. Among the shards of human bones and teeth, archaeologists have found ornaments fashioned from ivory, along with the abundant remains of animals.
The artefacts made by humans at the site allowed archaeologists to tie the ancient people to a cultural tradition known as the Gravettian. This culture came to span the entire European continent and is named after the site of La Gravette in France, where this stone age culture was first studied.
Researchers were able to directly date the human fossils using radiocarbon techniques. The shape and form of the remains told the scientists they were dealing with modern humans (Homo sapiens sapiens).
Eastern promise
One thing that intrigued researchers was the scarcity of human long bones (bones from the limbs) in the caves.
The site yielded countless limb bones from antelope, foxes and hares.
But the human remains consisted of vertebrae, teeth and skull bones no larger than 12cm. What is more, the positions of cut marks found on the human fragments were distinct from those found on the animal bones.
And while the bone marrow had been removed from butchered animals, it had been left alone in the case of the human remains at the site, explained co-author Sandrine Prat from the French National Centre for Scientific Research (CNRS) in Paris. She suspects this demonstrates that human bones were processed differently from those of animals. Human flesh was removed as part of ritual "cleaning", not to be eaten.
Defining culture
The finds offer anthropologists a glimpse into a very early and important human culture, said Professor Clive Finlayson, an evolutionary ecologist and director of the Gibraltar Museum.
"Gravettian culture is the culture that defines modern humans. These people had knives, lightweight tools, open air camps, they used mammoth bones to make tents," he said, adding that this was the earliest example of the Gravettian cultural tradition.
Professor Finlayson said that uncovering evidence of this culture in Ukraine gave weight to the idea that early modern people spread into Europe from the Russian plains, not north through the Balkans from the Middle East.
"What has excited me is that we have found evidence of humans where I would expect them to be, exploiting foods that I would expect them to be exploiting," Professor Finlayson told BBC News.
**********************************************
What happened to the "long bones," then? Were they buried somewhere, yet to be discovered? Did they dissolve away while the other bones/fragments survived inside the cave? So, perhaps humans were eating each other 32,000 years ago - or not. The jury is definitely still out on this one. Just because the marrow wasn't removed from the human bones doesn't mean the flesh wasn't consumed. Perhaps there was some big tribal ataboo about eating human bone marrow. We just don't know - and probably will never know.
Still not explained - how Homo Sapiens Sapiens, Homo Neanderthalis and Homo Denisovan could breed with each other and produce viable human beings that evidently also were able to produce offspring, enough at any rate, that some genes of both Neanderthal and Denisovan are found in modern human populations. (This was reported at New Science on June 16, 2010, Breeding with Neanderthals helped humans go global). Do you see the bias implicit in that article's title? As if Neanderthals were something less than fully human! Har!
Some people would have us believe that modern humans and the chimpanzee are like 99.98% related. Fine - so their DNA may share many similarities. Yet, humans cannot breed with chimpanzees, or great apes, or bonopos, etc. etc. Let's face it, there is a fundamental, unbridgeable difference between a human being and not-human ape-like being, and never the twain shall meet, not 2 million, 1 million, 100,000 or 10,000 years ago, and not 10,000, 100,000, 1 million or 2 million years from now. Neanderthals and Denisovans were fully human, and they bred with other humans. Their descendants walk among us today, and we know it now, for certain, because some of their unique DNA sequences survived in today's human population.
Thursday, December 23, 2010
And Then There Were Three...
From 'Sis. Thanks, 'Sis! There are now three "sub-species" of Homo Sapiens that are known to have interbred with each other. Stay tuned. Some day the scientists will actually figure it all out and get it RIGHT...
From The New York Times
Siberian Fossils Were Neanderthals’ Eastern Cousins, DNA Reveals
By CARL ZIMMER
Published: December 22, 2010
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.
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. [That's what they think they know - now.]
Dr. Paabo’s success with European Neanderthal fossils inspired him and his colleagues to look farther afield. They began to work with Anatoli Derevianko of the Russian Academy of Sciences, who explores Siberian caves in search of fossils of hominins (species more closely related to living humans than to chimpanzees, our closest living relatives).
Last year, Dr. Derevianko and his colleagues sent Dr. Paabo a nondescript fragment of a finger bone from a cave called Denisova. Dr. Derevianko thought that the fossil, which is at least 50,000 years old, might have belonged to one of the earliest humans to live in Siberia.
Dr. Paabo and his colleagues isolated a small bundle of DNA from the bone’s mitochondria, the energy-generating structures within our cells. Dr. Paabo and his colleagues were surprised to discover that the Denisova DNA was markedly different from that of either humans or Neanderthals. “It was a great shock to us that it was distinct from those groups,” Dr. Paabo said in an interview.
Dr. Paabo and his colleagues immediately set about to collect all the DNA in the Denisova finger bone. Once they had sequenced its genome, they sent the data to researchers at Harvard Medical School and the Broad Institute in Cambridge, Mass., to compare with other species.
The Massachusetts scientists concluded that the finger bone belonged to a hominin branch that split from the ancestors of Neanderthals roughly 400,000 years ago. Dr. Paabo and his colleagues have named this lineage the Denisovans.
Next, the researchers looked for evidence of interbreeding. Nick Patterson, a Broad Institute geneticist, compared the Denisovan genome to the complete genomes of five people, from South Africa, Nigeria, China, France and Papua New Guinea. To his astonishment, a sizable chunk of the Denisova genome resembled parts of the New Guinea DNA. [They need to do more cross-matching, but I suppose lack of funding is a big issue...]
“The correct reaction when you get a surprising result is, ‘What am I doing wrong?’ ” said Dr. Patterson. To see if the result was an error, he and his colleagues sequenced the genomes of seven more people, including another individual from New Guinea and one from the neighboring island of Bougainville. But even in the new analysis, the Denisovan DNA still turned up in the New Guinea and Bougainville genomes.
If the Denisovans did indeed have a range spreading from Siberia to South Asia, they must have been a remarkably successful kind of human. [I don't understand the surprise. We KNOW that people built rafts or canoes or some type of ocean-worthy craft and spread to the islands from southeast Asia at least 50,000 years ago.] And yet, despite having the entire genome of a Denisovan, Dr. Paabo cannot say much yet about what they were like. “By sequencing my complete genome, there’s very little you could predict about what I look like or how I behave,” he said.
One solid clue to what the Denisovans looked like emerged in January. Dr. Paabo and his team had flown to Novosibirsk to share their initial results with Dr. Derevianko. Dr. Derevianko then presented them with a wisdom tooth from Denisova.
Bence Viola, a paleoanthropologist in the Department of Human Evolution at the Max Planck Institute of Evolutionary Anthropology, who was at the meeting, was flummoxed. “I looked at it and said, ‘Ah, O.K., this is not a modern human, and it’s definitely not a Neanderthal,”’ said Dr. Viola. “It was just so clear.”
The tooth had oddly bulging sides, for one thing, and for another, its large roots flared out to the sides. Back in Germany, Dr. Paabo and his colleagues managed to extract some mitochondrial DNA from the tooth. It proved to be a nearly perfect match to that of the Denisova finger bone. [But not a perfect match - so not from the same person, but closely related? A bone and a tooth from two relatives who died in the same cave? We need more information! Unless all the articles I've read about mitochondrial DNA have been lying, this is only inherited through a mother. Is potential cross-contamination an issue?]
That match offers some hope that if researchers can find the same kind of tooth on a fossil skull, or perhaps even a complete skeleton, they’ll be able to see what these ghostly cousins and ancestors looked like in real life.
Dr. Bustamante also thinks that other cases of interbreeding are yet to be discovered. “There’s a lot of possibility out there,” he said. “But the only way to get at them is to sequence more of these ancient genomes.” [Or re-analyze and understand better what we already think we know! What will we think we know 30 years from now, for instance?]
From The New York Times
Siberian Fossils Were Neanderthals’ Eastern Cousins, DNA Reveals
By CARL ZIMMER
Published: December 22, 2010
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.
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. [That's what they think they know - now.]
Dr. Paabo’s success with European Neanderthal fossils inspired him and his colleagues to look farther afield. They began to work with Anatoli Derevianko of the Russian Academy of Sciences, who explores Siberian caves in search of fossils of hominins (species more closely related to living humans than to chimpanzees, our closest living relatives).
Last year, Dr. Derevianko and his colleagues sent Dr. Paabo a nondescript fragment of a finger bone from a cave called Denisova. Dr. Derevianko thought that the fossil, which is at least 50,000 years old, might have belonged to one of the earliest humans to live in Siberia.
Dr. Paabo and his colleagues isolated a small bundle of DNA from the bone’s mitochondria, the energy-generating structures within our cells. Dr. Paabo and his colleagues were surprised to discover that the Denisova DNA was markedly different from that of either humans or Neanderthals. “It was a great shock to us that it was distinct from those groups,” Dr. Paabo said in an interview.
Dr. Paabo and his colleagues immediately set about to collect all the DNA in the Denisova finger bone. Once they had sequenced its genome, they sent the data to researchers at Harvard Medical School and the Broad Institute in Cambridge, Mass., to compare with other species.
The Massachusetts scientists concluded that the finger bone belonged to a hominin branch that split from the ancestors of Neanderthals roughly 400,000 years ago. Dr. Paabo and his colleagues have named this lineage the Denisovans.
Next, the researchers looked for evidence of interbreeding. Nick Patterson, a Broad Institute geneticist, compared the Denisovan genome to the complete genomes of five people, from South Africa, Nigeria, China, France and Papua New Guinea. To his astonishment, a sizable chunk of the Denisova genome resembled parts of the New Guinea DNA. [They need to do more cross-matching, but I suppose lack of funding is a big issue...]
“The correct reaction when you get a surprising result is, ‘What am I doing wrong?’ ” said Dr. Patterson. To see if the result was an error, he and his colleagues sequenced the genomes of seven more people, including another individual from New Guinea and one from the neighboring island of Bougainville. But even in the new analysis, the Denisovan DNA still turned up in the New Guinea and Bougainville genomes.
If the Denisovans did indeed have a range spreading from Siberia to South Asia, they must have been a remarkably successful kind of human. [I don't understand the surprise. We KNOW that people built rafts or canoes or some type of ocean-worthy craft and spread to the islands from southeast Asia at least 50,000 years ago.] And yet, despite having the entire genome of a Denisovan, Dr. Paabo cannot say much yet about what they were like. “By sequencing my complete genome, there’s very little you could predict about what I look like or how I behave,” he said.
One solid clue to what the Denisovans looked like emerged in January. Dr. Paabo and his team had flown to Novosibirsk to share their initial results with Dr. Derevianko. Dr. Derevianko then presented them with a wisdom tooth from Denisova.
Bence Viola, a paleoanthropologist in the Department of Human Evolution at the Max Planck Institute of Evolutionary Anthropology, who was at the meeting, was flummoxed. “I looked at it and said, ‘Ah, O.K., this is not a modern human, and it’s definitely not a Neanderthal,”’ said Dr. Viola. “It was just so clear.”
The tooth had oddly bulging sides, for one thing, and for another, its large roots flared out to the sides. Back in Germany, Dr. Paabo and his colleagues managed to extract some mitochondrial DNA from the tooth. It proved to be a nearly perfect match to that of the Denisova finger bone. [But not a perfect match - so not from the same person, but closely related? A bone and a tooth from two relatives who died in the same cave? We need more information! Unless all the articles I've read about mitochondrial DNA have been lying, this is only inherited through a mother. Is potential cross-contamination an issue?]
That match offers some hope that if researchers can find the same kind of tooth on a fossil skull, or perhaps even a complete skeleton, they’ll be able to see what these ghostly cousins and ancestors looked like in real life.
Dr. Bustamante also thinks that other cases of interbreeding are yet to be discovered. “There’s a lot of possibility out there,” he said. “But the only way to get at them is to sequence more of these ancient genomes.” [Or re-analyze and understand better what we already think we know! What will we think we know 30 years from now, for instance?]
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