Research: DNA shows girl had one Denisovan parent, one Neanderthal

DNA from just a single cave in Siberia revealed that it had been occupied by two archaic human groups that had interbred with the newly arrived modern humans. This included both the Neanderthals, whom we knew about previously, and the Denisovans, who we didn’t even know existed and still know little about other than their DNA sequences. The DNA also revealed that one of the Denisovans had a Neanderthal ancestor a few hundred generations back in his past…

Now, the same cave has yielded a bone fragment that indicates the interbreeding may have been common. DNA sequencing revealed that the bone fragment’s original owner had a mom that was Neanderthal and a father who was Denisovan. The fact that we have so few DNA samples from this time and that one is the immediate product of intermating gives us a strong hint that we should expect more examples in the future.

The Denisova Cave sits within Russia near its borders with China, Kazakhstan, and Mongolia. It appears to have conditions that favor the preservation of ancient DNA, as bones from the site have yielded high-quality genomes from both Neanderthals and Denisovans. It does not seem to have favored the preservation of skeletons themselves, as most material has been fragmentary; all we know about the appearance of Denisovans comes from a molar and a small finger bone, though dating indicates they occupied the cave more than 30,000 years after the Neanderthal.

Fascinating stuff…even if you’re already beyond fundamentalist fairy-tales.

Cave dweller menus were limited by what’s available – from Woolly rhino to mushrooms

❝ Eating like a caveman meant chowing down on woolly rhinos and sheep in Belgium, but munching on mushrooms, pine nuts and moss in Spain. It all depended on where they lived, new research shows.

❝ Scientists got a sneak peek into the kitchen of three Neanderthals by scraping off the plaque stuck on their teeth and examining the DNA. What they found smashes a common public misconception that the caveman diet was mostly meat. They also found hints that one sickly teen used primitive versions of penicillin and aspirin to help ease his pain.

The dental plaque provides a lifelong record of what went in the Neanderthals’ mouths and the bacteria that lived in their guts, said study co-author Alan Cooper, director of the Australian Centre for Ancient DNA in Adelaide.

“It’s like a fossil,” he said.

❝ While past studies showed varied Neanderthal diets, genetic testing allowed researchers to say what kind of meat or mushrooms they ate, Cooper said. The 42,000-year-old Belgian Neanderthal’s menu of sheep and woolly rhino reflected what roamed in the plains around the Neanderthal’s home, he said. The research is in Wednesday’s journal Nature…

There were no signs of meat in the diet of the two 50,000-year-old Spanish Neanderthals, but calling them vegetarians would be a stretch, Cooper said. Their own bones showed that they were eaten by cannibals.

I don’t doubt that the politicians, priests and pundits of the time provided believable reasons for every part of life – from diet to ritual – even if they were crap. Part of the job description that hasn’t changed.

Some Pacific Islanders have DNA of a previously unknown human ancestor

papua-new-guinea

❝ Most everyone knows that the islands of the South Pacific are some of the most remote and unique places on Earth, but a new study reveals just how unique they really are.

…Researchers have found traces of a previously unknown extinct hominid species in the DNA of the Melanesians, a group living in an area northeast of Australia that encompasses Papua New Guinea and the surrounding islands.

❝ A computer analysis suggests that the unidentified ancestral hominid species found in Melanesian DNA is unlikely to be either Neanderthal or Denisovan, the two known predecessors of humankind to this point.

❝ Archaeologists have found many Neanderthal fossils in Europe and Asia, and although the only Denisovan DNA comes from a finger bone and a couple of teeth discovered in a Siberian cave, both species are well represented in the fossil record.

But now genetic modeling of the Melanesians has revealed a third, different human ancestor that may be an extinct, distinct cousin of the Neanderthals.

“We’re missing a population, or we’re misunderstanding something about the relationships,” said researcher Ryan Bohlender…“Human history is a lot more complicated than we thought it was.”

One of the confounding delights of scientific methods becoming more accurate, more capable of revealing features contributing to a much larger system – the analysis can become more complex and expand the search for knowledge at the same time.

Genetic evidence of modern human DNA in a Neanderthal — Huh? Wha?

Using several different methods of DNA analysis, an international research team has found what they consider to be strong evidence of an interbreeding event between Neanderthals and modern humans that occurred tens of thousands of years earlier than any other such event previously documented.

…In NATURE the team publishes evidence of interbreeding that occurred an estimated 100,000 years ago. More specifically the scientists provide the first genetic evidence of a scenario in which early modern humans left the African continent and mixed with archaic (now-extinct) members of the human family prior to the migration “out of Africa” of the ancestors of present-day non-Africans, less than 65,000 years ago.

❝ “It’s been known for several years, following the first sequencing of the Neanderthal genome in 2010, that Neanderthals and humans must have interbred,” says Professor Adam Siepel, a co-team leader and Cold Spring Harbor Laboratory (CSHL) quantitative biologist. “But the data so far refers to an event dating to around 47,000-65,000 years ago, around the time that human populations emigrated from Africa. The event we found appears considerably older than that event…”

❝ “One very interesting thing about our finding is that it shows a signal of breeding in the ‘opposite’ direction from that already known,” Siepel notes. “That is, we show human DNA in a Neanderthal genome, rather than Neanderthal DNA in human genomes.”

This finding, the result of several kinds of advanced computer modeling algorithms comparing complete genomes of hundreds of contemporary humans with complete and partial genomes of four archaic humans, has implications for our knowledge of human migration patterns.

The article proceeds from this point to examination of several intertwining themes of interbreeding between different strands of the evolutionary vines that tie us all to our species. A worthwhile read.

It also validates a theme long held as strong among my Highland antecedents – whether critical or not – that our species [and any near relative] is ready to have sex with anyone willing to stand still long enough to enjoy it.

DNA yields secrets of early humans


Universal Human

DNA analysis of a 45,000-year-old human has helped scientists pinpoint when our ancestors interbred with Neanderthals…The genome sequence from a thigh bone found in Siberia shows the first episode of mixing occurred between 50,000 and 60,000 years ago.

The male hunter is one of the earliest modern humans discovered in Eurasia.

The study in Nature journal also supports the finding that our species emerged from Africa some 60,000 years ago, before spreading around the world…

The work of Prof Svante Paabo, from the Max Planck Institute in Leipzig, Germany, is rewriting the story of humanity. Prof Paabo and his colleagues have pioneered methods to extract DNA from ancient human remains and read its genetic code.

From this sequence, the scientist has been able to decipher an increasingly detailed story of modern humans as they spread across the globe.

“The amazing thing is that we have a good genome of a 45,000-year-old person who was close to the ancestor of all present-day humans outside Africa…”

Prof Paabo has analysed DNA from part of a leg bone of a man that lived in Western Siberia around 45,000 years ago. This is a key moment at the cross roads of the world, when modern humans were on the cusp of an expansion into Europe and Asia.

The key finding was that the man had large, unshuffled chunks of DNA from a now extinct species of human, Neanderthals, who evolved outside of Africa.

“Our analysis shows that modern humans had already interbred with Neanderthals then, and we can determine when that first happened much more precisely than we could before…”

Prof Paabo’s 45,000-year-old man seems to have lived at a point that was both geographically, and in time, a crossroads for humanity…”This does seem to mark a watershed where modern humans were pushing the boundaries further and further in their dispersal out of Africa,” according to Prof Chris Stringer.

Prof Paabo also compared the DNA of the man living 45,000 years ago with those living today. He found that the man was genetically midway between Europeans and Asians – indicating he lived close to the time before our species separated into different racial groups.

Fascinating stuff. I’ve had DNA tests that determined the coarser texture of how my ancestors spread from their African genesis into the steppes of Central Asia. Eventually ending up traveling west to the Scottish Highlands and, then, sweeping back east to the Danube before retreating to stay in Scotland.

Neanderthal clue to cancer origins


Abnormal Neanderthal bone (above) compared with normal Neanderthal specimen (below)

A Neanderthal living 120,000 years ago had a cancer that is common today, according to a fossil study.

A fossilised Neanderthal rib found in a shallow cave at Krapina, Croatia, shows signs of a bone tumour…The discovery is the oldest evidence yet of a tumour in the human fossil record, say US scientists.

The research, published in the journal PLOS One, gives clues to the complex history of cancer in humans.

Until now, the earliest known bone cancers have been identified in ancient Egyptian remains from about 1,000-4,000 years ago.

It’s the oldest tumour found in the human fossil record,” Dr David Frayer, the University of Kansas anthropologist who led the US team, told BBC News.

“It shows that living in a relatively unpolluted environment doesn’t necessarily protect you against cancer, even if you were a Neanderthal living 120,000 years ago.”

The fossil was uncovered from an important archaeological site that has yielded almost 900 ancient human bones, along with stone tools…The tumour was diagnosed by a medical radiologist from X-rays and CT scans.

Although efforts to extract ancient DNA from the Neanderthal fossil have proved unsuccessful, the researchers hope other fossils may shed light on cancer in prehistoric humans.

Commenting on the study, Kat Arney, science information manager at Cancer Research UK, said: “Some people think that cancer is only a modern disease, but there’s evidence from fossils, bones and mummies that it’s actually many thousands of years old.

Opens up a whole new range of scary possibilities – but, I’m not even up to an educated guess on this narrow topic. So, I’ll shut up.

Not-so-light Neanderthal lunch on the outskirts of Paris

French archaeologists have uncovered a rare, near-complete skeleton of a mammoth in the countryside near Paris, alongside tiny fragments of flint tools suggesting the carcass may have been cut into by prehistoric hunters.

The archaeologists say that if that hypothesis is confirmed, their find would be the clearest ever evidence of interaction between mammoths and ancient cavemen in this part of Europe

Archaeologists came across the giant bones by accident while they were excavating ancient Roman remains in a quarry near the town of Changis-sur-Marne, 30 km east of Paris.

The mammoth, which the archaeologists have named “Helmut”, is thought to be between 100,000 and 200,000 years old and is only the fourth near-complete specimen to be found in France…

Scientists believe Helmut, a woolly mammoth, may have become stuck in mud or drowned…

Mammoth remains are commonest in the frozen climates of Siberia, where around 140 specimens have been found including some of the world’s best-preserved carcasses.

The prehistoric animal disappeared from Western Europe around 10,000 years ago, most likely due to climate change and hunting.

We evolved as omnivores, folks. If digestible, we ate anything we could kill, find as some other critter’s leftovers, or pluck it out of a bog for lunch.

The quest for scarce goods meant we ate anything that wouldn’t kill us.

First cave painters may have been Neanderthal

European cave paintings are older than previously thought, raising the possibility that Neanderthals rather than Homo sapiens were the earliest painters…That’s not yet certain: The paintings may have been made by humans at an unexpectedly early date, which would itself raise intriguing questions, though none so tantalizing as Neanderthal painters…

Researchers led by João Zilhão and Alistair Pike of the United Kingdom’s University of Bristol measured the ages of 50 paintings in 11 Spanish caves. The art, considered evidence of sophisticated symbolic thinking, has traditionally been attributed to modern humans, who reached Europe about 40,000 years ago…

Instead of carbon, Pike and João Zilhão’s team calibrated their molecular clocks by studying mineral deposits that form naturally on cave surfaces, including paintings. The thicker the deposits, the older the painting. And as the researchers describe in a June 14 Science paper, some of the paintings are very old indeed.

Some handprint outlines are at least 37,000 years old. Several red circles are at least 41,000 years old and may be several thousand years older. That’s 10,000 years older than paintings in France, which until now were considered the oldest cave art…

This is still just a hypothesis, one that needs to be tested by dating of many more paintings — the artists were not human. Maybe they were Neanderthals.

If so, the paintings would be a pièce de résistance addition to a decade of Neanderthal research that’s showed how our closest evolutionary relatives, long considered less intelligent than humans, were truly sophisticated thinkers capable of symbolism, social planning and empathy. Paintings would provide the last bit of evidence needed to throw out the image of Neanderthals as archetypally dumb, Zilhao said.

I’ve always been ready to be surprised by individuals of our own species and many others. You don’t need prohibitive odds to allow for a few specially talented individuals who exceed the norm of capabilities.

Our ancestry keeps getting more complex

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 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…

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