Biblical Archeology > Fascinating discoveries in the field of Genetics - including Adam's rib

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We carry DNA from extinct cousins like Neanderthals.

Science is now revealing their genetic legacy

John Gurche helps people understand what ancient humans looked like by creating lifelike models based on archaeological finds. The work requires a mix of artistic skill and scientific knowledge.

(Sept. 24) (AP Video: Michael Hill)

BY LAURA UNGAR AND MADDIE BURAKOFF

Updated 8:38 AM PDT, September 27, 2023

Neanderthals live on within us.

These ancient human cousins, and others called Denisovans, once lived alongside our early Homo sapiens ancestors. They mingled and had children. So some of who they were never went away — it’s in our genes. And science is starting to reveal just how much that shapes us.

Using the new and rapidly improving ability to piece together fragments of ancient DNA, scientists are finding that traits inherited from our ancient cousins are still with us now, affecting our fertility, our immune systems, even how our bodies handled the COVID-19 virus.

“We’re now carrying the genetic legacies and learning about what that means for our bodies and our health,” said Mary Prendergast, a Rice University archeologist.

In the past few months alone, researchers have linked Neanderthal DNA to a serious hand disease, the shape of people’s noses and various other human traits. They even inserted a gene carried by Neanderthals and Denisovans into mice to investigate its effects on biology, and found it gave them larger heads and an extra rib.

In the Biblical story of Creation, God took a rib from Adam to make Eve. Man has been missing this rib ever since. Isn't that curious?

Much of the human journey remains a mystery. But Dr. Hugo Zeberg of the Karolinska Insitute in Sweden said new technologies, research and collaborations are helping scientists begin to answer the basic but cosmic questions: “Who are we? Where did we come from?”

And the answers point to a profound reality: We have far more in common with our extinct cousins than we ever thought.

NEANDERTHALS WITHIN US

Until recently, the genetic legacy from ancient humans was invisible because scientists were limited to what they could glean from the shape and size of bones. But there has been a steady stream of discoveries from ancient DNA, an area of study pioneered by Nobel Prize winner Svante Paabo who first pieced together a Neanderthal genome.

Advances in finding and interpreting ancient DNA have allowed them to see things like genetic changes over time to better adapt to environments or through random chance.

It’s even possible to figure out how much genetic material people from different regions carry from the ancient relatives our predecessors encountered.

Research shows some African populations have almost no Neanderthal DNA, while those from European or Asian backgrounds have 1% to 2%. Denisovan DNA is barely detectable in most parts of the world but makes up 4% to 6% of the DNA of people in Melanesia, which extends from New Guinea to the Fiji Islands.

That may not sound like much, but it adds up. “Half of the Neanderthal genome is still around, in small pieces scattered around modern humans,” said Zeberg, who collaborates closely with Paabo.

It’s also enough to affect us in very real ways. Scientists don’t yet know the full extent, but they’re learning it can be both helpful and harmful.

For example, Neanderthal DNA has been linked to auto-immune diseases like Graves’ disease and rheumatoid arthritis. When Homo sapiens came out of Africa, they had no immunity to diseases in Europe and Asia, but Neanderthals and Denisovans already living there did.

“By interbreeding with them, we got a quick fix to our immune systems, which was good news 50,000 years ago,” said Chris Stringer, a human evolution researcher at the Natural History Museum in London. “The result today is, for some people, that our immune systems are oversensitive, and sometimes they turn on themselves.”

Similarly, a gene associated with blood clotting believed to be passed down from Neanderthals in Eurasia may have been helpful in the “rough and tumble world of the Pleistocene,” said Rick Potts, director of the human origins program at the Smithsonian Institution. But today it can raise the risk of stroke for older adults. “For every benefit,” he said, “there are costs in evolution.”

In 2020, research by Zeberg and Paabo found that a major genetic risk factor for severe COVID-19 is inherited from Neanderthals. “We compared it to the Neanderthal genome and it was a perfect match,” Zeberg said. “I kind of fell off my chair.”

The next year, they found a set of DNA variants along a single chromosome inherited from Neanderthals had the opposite effect: protecting people from severe COVID.

The list goes on: Research has linked Neanderthal genetic variants to skin and hair color, behavioral traits, skull shape and Type 2 diabetes. One study found that people who report feeling more pain than others are likely to carry a Neanderthal pain receptor. Another found that a third of women in Europe inherited a Neanderthal receptor for the hormone progesterone, which is associated with increased fertility and fewer miscarriages.

Much less is known about our genetic legacy from Denisovans – although some research has linked genes from them to fat metabolism and better adaptation to high altitudes. Maanasa Raghavan, a human genetics expert at the University of Chicago, said a stretch of Denisovan DNA has been found in Tibetans, who continue to live and thrive in low-oxygen environments today.

Scientists have even found evidence of “ghost populations” — groups whose fossils have yet to be discovered — within modern humans’ genetic code.

SO WHY DID WE SURVIVE?

In the past, the tale of modern humans’ survival “was always told as some success story, almost like a hero’s story,” in which Homo sapiens rose above the rest of the natural world and overcame the “insufficiencies” of their cousins, Potts said.

“Well, that simply is just not the correct story.”

Neanderthals and Denisovans had already existed for thousands of years by the time Homo sapiens left Africa. Scientists used to think we won out because we had more complex behavior and superior technology. But recent research shows that Neanderthals talked, cooked with fire, made art objects, had sophisticated tools and hunting behavior, and even wore makeup and jewelry.

Several theories now tie our survival to our ability to travel far and wide.

“We spread all over the world, much more than these other forms did,” Zeberg said.

While Neanderthals were specially adapted to cold climates, Potts said, Homo sapiens were able to disperse to all different kinds of climates after emerging in tropical Africa. “We are so adaptable, culturally adaptable, to so many places in the world,” he said.

Meanwhile, Neanderthals and Denisovans faced harsh conditions in the north, like repeated ice ages and ice sheets that likely trapped them in small areas, said Eleanor Scerri, an archeologist at Germany’s Max Planck Institute for Geoanthropology. They lived in smaller populations with a greater risk of genetic collapse.

Plus, we had nimble, efficient bodies, Prendergast said. It takes a lot more calories to feed stocky Neanderthals than comparatively skinny Homo sapiens, so Neanderthals had more trouble getting by, and moving around, especially when food got scarce.

Janet Young, curator of physical anthropology at the Canadian Museum of History, pointed to another intriguing hypothesis – which anthropologist Pat Shipman shared in one of her books –- that dogs played a big part in our survival. Researchers found the skulls of domesticated dogs in Homo sapiens sites much further back in time than anyone had found before. Scientists believe dogs made hunting easier.

By around 30,000 years ago, all the other kinds of hominins on Earth had died off, leaving Homo sapiens as the last humans standing.

‘INTERACTION AND MIXTURE’

Still, every new scientific revelation points to how much we owe our ancient cousins.

Human evolution was not about “survival of the fittest and extinction,” said John Hawks, a paleoanthropologist at the University of Wisconsin-Madison. It’s about “interaction and mixture.”

Researchers expect to learn more as science continues to advance, allowing them to extract information from ever-tinier traces of ancient lives. Even when fossils aren’t available, scientists today can capture DNA from soil and sediment where archaic humans once lived.

And there are less-explored places in the world where they hope to learn more. Zeberg said “biobanks” that collect biological samples will likely be established in more countries.

As they delve deeper into humanity’s genetic legacy, scientists expect to find even more evidence of how much we mixed with our ancient cousins and all they left us.

“Perhaps,” Zeberg said, “we should not see them as so different.”

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Covid-19 > Covid Appeals to the Neanderthal in Us; Germany - State of Emergency; Netherlands Cancels Many Operations

DNA from Neanderthals affects vulnerability to covid-19

Why Africa avoids Covid disaster

Feb 24th 2021

As best as scientists can tell, Neanderthals died out around 40,000 years ago. But they did not vanish from the Earth entirely. In the past decade it has become clear that Neanderthals mated with the ancestors of modern humans, and that at least some of those unions produced viable offspring. The upshot is that almost half of the Neanderthal genome still survives, scattered in small quantities among almost all modern people’s dna. (The exception is those with mostly African ancestors, for Neanderthals seem never to have lived in Africa.)

My previous post on Covid-19, contains an article called: Scientists mystified, wary, as Africa avoids COVID disaster. It appears the answer has been found. It appears the answer was found way back in February, but scientists are still mystified!!!

Such genes have been associated with everything from hairiness to fat metabolism. Many seem to be related to the immune system, and to affect the risk of developing diseases including lupus, Crohn's and diabetes. A pair of recent papers suggest covid-19 belongs on that list as well. Two long sections of dna, both inherited from Neanderthals, appear to confer resistance or susceptibility to severe covid-19, depending on which is present.

The work was led by Hugo Zeberg and Svante Paabo at the Max Planck Institute for Evolutionary Anthropology in Leipzig, whose researchers pioneered the study of Neanderthal dna. Their first paper, published in Nature in September, described one Neanderthal dna string, known as a “haplotype”, that is associated with a higher risk of serious illness. Having one copy of the haplotype, which is found on the third of the 46 chromosomes possessed by humans, doubles the chances of a trip to intensive care. Those unlucky enough to possess two copies—one from each parent—face an even higher risk.

That genetic bad luck is not evenly distributed. The gene-sequence is most common among people of South Asian descent, with 63% of the population of Bangladesh carrying at least one copy; and among Europeans, where the prevalence is around 16%. As expected, it is virtually absent from Africa. More strikingly, it is also very rare in large swathes of eastern Asia.

Exactly what the haplotype does is not clear. One gene within it encodes a protein that interacts with the cellular receptors that sars-cov-2 (the virus which causes covid-19) uses to enter cells and hijack them. The haplotype is also thought to be involved in the production of signalling proteins, called cytokines, that help to regulate the immune system. An overly aggressive immune response is one mechanism by which covid-19 kills.

On the other hand, some of those cytokines protect against cholera. The researchers speculate that may be why the haplotype is common in Bangladesh and India, where cholera has long been a problem. And there is evidence that, even as evolution has been boosting the haplotype in some populations, it has been working to remove it from others. “The frequency differences between South Asia and East Asia are so dramatic that we cannot help but suspect that past selection is responsible,” says Dr Paabo.

The second study, published this week in Proceedings of the National Academy of Sciences, concerns another Neanderthal haplotype, found on chromosome 12. Its effect is protective, though it is also less potent: having a single copy is associated with a 22% lower chance of critical illness.

This helpful sequence is more well-travelled than the harmful one. It is present in every part of the world except sub-Saharan Africa. Between 25% and 35% of the population of Eurasia carry at least one copy. In Vietnam and eastern China more than half the population are carriers. It also exists, at much lower rates, among American populations of mainly African descent, many of whom will have some more recent Eurasian ancestry as well.

Scientists also have a better idea of what it does, for it was known to researchers even before the news of its Neanderthal origin. The haplotype hampers the spread of rna viruses, of which sars-cov-2 is one, by driving cells infected with them to self-destruct quickly. It is known to provide at least some protection against West Nile virus, hepatitis C and, intriguingly, sars-cov-1, which caused the sars outbreak that began in 2002.

Once again, the hand of natural selection is visible. The genes in the chromosome-12 haplotype are found in other mammals, and have been lost several times in other species. That hints that carrying them comes at a significant cost, leading them to be removed if they are not being heavily used. That they are common in most human populations suggests rna viruses have been a thorn in humanity's side for much of its evolutionary history.

The researchers hope that their work might help shed light on why some countries, and some populations within countries, appear to have been hit harder by covid-19 than others. They point out, for instance, that Britons of Bangladeshi heritage suffer severe covid-19 at roughly twice the rate of the general population. But disentangling the effects of dna will be tricky. Age, obesity and sex, among other things, all influence the severity of covid-19. Comparisons between countries are complicated by definitional differences and the difficulty of performing accurate counts, especially in poor countries. Despite the prevalence of the harmful haplotype, the official covid-19 death rate in Bangladesh is just 5.1 per 100,000, an order of magnitude lower than in countries where the haplotype is much rarer.

Still, a reminder that genetics matter alongside those other factors is still useful. If covid-19 becomes an endemic disease, as seems likely, cheap gene sequencing may, in future, help doctors assess which patients are likely to be vulnerable to its worst effects. Understanding the mechanisms by which genes confer resistance or susceptibility may help with the search for drugs. And history suggests that sars-cov-2 is unlikely to be the last novel coronavirus to make the jump to humans. If some populations are likely to be more vulnerable than others, that is worth knowing for next time. 

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Covid rates take Germany to ‘nationwide state of emergency’

19 Nov, 2021 14:16

FILE PHOTO. ESSEN, GERMANY. © AFP / Ina FASSBENDER

 

Germany has been plunged into a “nationwide state of emergency” because of its current high level of Covid infections, acting health minister Jens Spahn has said. He also refused to rule out further lockdowns.

“The situation is serious, the dynamic is unbroken,” Spahn told a press conference Friday.

“The incidence has increased fivefold in four weeks. We see sadly high values in the death rate. We are in a national emergency.”

Spahn refused to rule out the possibility of another lockdown, saying that, in such a drastic health situation, “we can't rule anything out.”

The head of the Robert Koch Institute (RKI), Lothar Wieler, added to the gloomy picture by saying that “all of Germany is one big outbreak,” with an estimated half a million active Covid cases in the country – and numbers rising. For the third day in a row, more than 50,000 cases have been registered in the country, while the death toll in Germany since the start of the pandemic is above 98,700, according to figures compiled by the RKI.

Wieler added that, with many hospitals already overwhelmed, more should be done to tackle the spread of the virus. Besides obvious measures such as vaccination and wearing masks, he also suggested closing poorly ventilated bars.

On Thursday, lawmakers in the Bundestag approved new measures in the fight against coronavirus, including requirements to prove vaccination status, a negative test, or proof of recovery from infection before employees can access communal workspaces or use public transport. The measures will have to be passed by the upper house before they can take effect.

Neighboring Austria announced on Friday that it would enter full lockdown as of Monday, November 22.

Does this mean that central Europe is full of Neanderthals? Asking for a friend!

Dutch hospitals ditching operations as Covid surges

34,000 to 50,000 ‘healthy life years’ had been lost due to the first Covid-19 wave alone

19 Nov, 2021 18:12

FILE PHOTO. Sommelsdijk, the Netherlands. © AFP / JEFFREY GROENEWE

Hospitals in the Netherlands have begun delaying certain operations to free-up ICU beds during a record wave of Covid-19 infections, while an infectious diseases researcher has warned of an impending ‘Code Black’ in the sector.

The country set a daily national record for new Covid infections on Thursday, registering around 23,600 cases. It was the third day in a row of the figure topping 20,000.

The population of the Netherlands is about 17.5 million.

To make more staff available for Covid wards, a number of operations, including those for cancer and heart patients, are being canceled from this week on, Dutch healthcare officials have said. Fewer than 200 beds remained available in Dutch ICUs as of Thursday, while Friday figures show almost half (47.8%) of occupied ICU beds were being used by Covid patients.

"These are cancer patients that should actually be operated-on within six weeks of diagnosis, and that won't be met in all cases. It's also heart patients," said a spokesperson for the National Coordination Center for Patient Distribution (LCPS).

Meanwhile, new calculations by an infectious disease modeller at Wageningen University & Research suggest that a so-called ‘Code Black’ in hospitals is looming. The emergency designation means that patient safety is at risk and, if declared, would mean many people with life-threatening illnesses cannot go to the ICU, while doctors have to prioritize who to treat.

According to recent estimates from the Dutch Healthcare Authority (NZa), up to 200,000 operations were not performed as a result of urgently needed Covid care since the start of the pandemic. On Thursday, the NZa revealed that almost a quarter of operating rooms across the country are not currently in use due to a combination of Covid patient pressures and rising staff absences due to illness.

It is not yet clear what impact the delayed care will have on public health. In December 2020, the Dutch National Institute for Public Health and the Environment (RIVM) calculated that an estimated 34,000 to 50,000 ‘healthy life years’ had been lost due to the first Covid-19 wave alone.

There Used to be Nine Species of Human. What Happened to Them?

The disappearance of these other species resembles a mass extinction. But there’s no obvious environmental catastrophe, except for the rise of Homo Sapiens

There is a lot of imagination in anthropology. Take what you want from this, but remember, these theories will continue to evolve for some time.

The spread of modern humans out of Africa has caused a sixth mass extinction, a greater than 40,000-year event extending from the disappearance of Ice Age mammals to the destruction of rainforests by civilisation today.Getty Images

The Conversation

Nine human species walked the Earth 300,000 years ago. Now there is just one. The Neanderthals, Homo Neanderthalensis, were stocky hunters adapted to Europe’s cold steppes. The related Denisovans inhabited Asia, while the more primitive Homo Erectus lived in Indonesia, and Homo Rhodesiensis in central Africa.

Several short, small-brained species survived alongside them: Homo Naledi in South Africa, Homo Luzonensis in the Philippines, Homo Floresiensis (“hobbits”) in Indonesia, and the mysterious Red Deer Cave People in China. Given how quickly we’re discovering new species, more are likely waiting to be found.

By 10,000 years ago, they were all gone. The disappearance of these other species resembles a mass extinction. But there’s no obvious environmental catastrophe – volcanic eruptions, climate change, asteroid impact – driving it. Instead, the extinctions’ timing suggests they were caused by the spread of a new species, evolving 260,000-350,000 years ago in Southern Africa: Homo sapiens.

Unless there was a global flood!

The spread of modern humans out of Africa has caused a sixth mass extinction, a greater than 40,000-year event extending from the disappearance of Ice Age mammals to the destruction of rainforests by civilisation today. 

But were other humans the first casualties?

We are a uniquely dangerous species. We hunted wooly mammoths, ground sloths and moas to extinction. We destroyed plains and forests for farming, modifying over half the planet’s land area. We altered the planet’s climate. But we are most dangerous to other human populations, because we compete for resources and land.

History is full of examples of people warring, displacing and wiping out other groups over territory, from Rome’s destruction of Carthage, to the American conquest of the West and the British colonisation of Australia. There have also been recent genocides and ethnic cleansing in Bosnia, Rwanda, Iraq, Darfur and Myanmar. Like language or tool use, a capacity for and tendency to engage in genocide is arguably an intrinsic, instinctive part of human nature. There’s little reason to think that early Homo sapiens were less territorial, less violent, less intolerant – less human.

History is full of examples of people warring, displacing and wiping out other groups over territory

Optimists have painted early hunter-gatherers as peaceful, noble savages, and have argued that our culture, not our nature, creates violence. But field studies, historical accounts, and archaeology all show that war in primitive cultures was intense, pervasive and lethal. Neolithic weapons such as clubs, spears, axes and bows, combined with guerrilla tactics like raids and ambushes, were devastatingly effective. Violence was the leading cause of death among men in these societies, and wars saw higher casualty levels per person than World Wars I and II.

Old bones and artefacts show this violence is ancient. The 9,000-year-old Kennewick Man, from North America, has a spear point embedded in his pelvis. The 10,000-year-old Nataruk site in Kenya documents the brutal massacre of at least 27 men, women, and children.

It’s unlikely that the other human species were much more peaceful. The existence of cooperative violence in male chimps suggests that war predates the evolution of humans. Neanderthal skeletons show patterns of trauma consistent with warfare. But sophisticated weapons likely gave Homo sapiens a military advantage. The arsenal of early Homo sapiens probably included projectile weapons like javelins and spear-throwers, throwing sticks and clubs.

Complex tools and culture would also have helped us efficiently harvest a wider range of animals and plants, feeding larger tribes, and giving our species a strategic advantage in numbers.

The ultimate weapon

But cave paintings, carvings, and musical instruments hint at something far more dangerous: a sophisticated capacity for abstract thought and communication. The ability to cooperate, plan, strategise, manipulate and deceive may have been our ultimate weapon.

The incompleteness of the fossil record makes it hard to test these ideas. But in Europe, the only place with a relatively complete archaeological record, fossils show that within a few thousand years of our arrival , Neanderthals vanished. Traces of Neanderthal DNA in some Eurasian people prove we didn’t just replace them after they went extinct. We met, and we mated.

Elsewhere, DNA tells of other encounters with archaic humans. East Asian, Polynesian and Australian groups have DNA from Denisovans. DNA from another species, possibly Homo erectus, occurs in many Asian people. African genomes show traces of DNA from yet another archaic species. The fact that we interbred with these other species proves that they disappeared only after encountering us.

But why would our ancestors wipe out their relatives, causing a mass extinction – or, perhaps more accurately, a mass genocide?

The answer lies in population growth. Humans reproduce exponentially, like all species. Unchecked, we historically doubled our numbers every 25 years. And once humans became cooperative hunters, we had no predators. Without predation controlling our numbers, and little family planning beyond delayed marriage and infanticide, populations grew to exploit the available resources.

Further growth, or food shortages caused by drought, harsh winters or overharvesting resources would inevitably lead tribes into conflict over food and foraging territory. Warfare became a check on population growth, perhaps the most important one.

Our elimination of other species probably wasn’t a planned, coordinated effort of the sort practised by civilisations, but a war of attrition. The end result, however, was just as final. Raid by raid, ambush by ambush, valley by valley, modern humans would have worn down their enemies and taken their land.

Yet the extinction of Neanderthals, at least, took a long time – thousands of years. This was partly because early Homo sapiens lacked the advantages of later conquering civilisations: large numbers, supported by farming, and epidemic diseases like smallpox, flu, and measles that devastated their opponents. But while Neanderthals lost the war, to hold on so long they must have fought and won many battles against us, suggesting a level of intelligence close to our own.

Today we look up at the stars and wonder if we’re alone in the universe. In fantasy and science fiction, we wonder what it might be like to meet other intelligent species, like us, but not us. It’s profoundly sad to think that we once did, and now, because of it, they’re gone.

Nick Longrich, Senior Lecturer, Paleontology and Evolutionary Biology, University of Bath.

Denisovans, Mysterious Human Relatives, Looked Just Like Us in At Least 1 Way

Rediscovery of missing finger bone shows slender fingertips

unlike knobby Neanderthal finger bones

Some human groups have more than five per cent Denisovan DNA

Emily Chung · CBC News 

Denisovans were originally identified from DNA in a bone from the base of the pinky finger of a young girl, shown above. Now the rest of that bone has been rediscovered, showing the entire bone is similar to that of modern humans and different from the fingertip of Neanderthals, which are more closely related to Denisovans.

They may have had huge, brutish-looking teeth, but Denisovans — ancient cousins of humans and Neanderthals — had slender, delicate fingertips like ours, a new study shows.

After rediscovering a missing piece of one of only five Denisovan fossils ever discovered, researchers from France, Russia and Canada digitally reconnected the two halves from the tip of the pinky finger from a Denisovan girl. 

The reconstruction showed it was indistinguishable from a human fingertip and different from the knobbed or clubbed fingertip bones of Neanderthals, they reported Wednesday in the journal Science Advances.

The finding is a small piece of the puzzle in figuring out who the mysterious Denisovans were, given that only five small fossils of the hominin species have ever been found.

"Until now, all we knew was how their teeth looked," said Bence Viola, a University of Toronto anthropologist who co-authored the paper. "All these little pieces allow us to build a picture of who the Denisovans were."

The image above shows the bone from the tip of the pinky finger from, left to right, a Neanderthal, modern human and Denisovan. (Bennett et al./Science Advances, licensed under CC BY NC)

The new finding suggests researchers looking for Denisovan fossils might have to be more open-minded about what to look for, and that some fossils previously identified as modern humans may, in fact, be Denisovans, said Eva-Maria Geigl, an anthropologist at the Institut Jacques Monod at the Centre national de la recherche scientifique and the University of Paris who also co-authored the report.

More closely related to Neanderthals

Denisovans were first identified in 2010 as a new species of hominin using DNA extracted from the bottom half of the finger bone. Genetic analysis showed Denisovans were more closely related to Neanderthals than modern humans, but Denisovans interbred widely with modern humans, and some human groups have more than five per cent Denisovan DNA.

Re-writing Early History of Mankind - Again

Neanderthals - Incest, Interbreeding and Possibly Pedophilia

Complex Human DNA Trail Provides Some Interesting Surprises - Neanderthals & humans interbred 100,000 years ago

However, scientists know little about what they looked like, other than the fact they had massive molars similar to those of a more ancient hominin, Homo erectus.

Viola was a postdoctoral researcher at the lab Max Planck Institute for Evolutionary Anthropology in Leipzig that analyzed the DNA from the bone from the base of the fingertip. What the researchers didn't know at the time was that after the bone was excavated from Denisova Cave in Siberia in 2008, it was cut in half.

The finger bone was excavated at Denisova Cave in 2008. (Bence Viola)

They only learned a couple of years ago that the other half had been sent to a different lab in the U.S. for analysis.

That half was subsequently photographed and measured by Geigl, who noticed that it had been cut. After she analyzed it genetically, she realized that it had exactly the same DNA as the bone that identified the Denisovans as a new species, and therefore must be part of the same bone.

But because the DNA analysis had already been published by the German researchers, and she was asked to return the bone to the U.S., she set the project aside.

2 halves reunited

Some years later, she said, she spoke to the Viola and the German researchers about the bone, which they didn't know about.

"It was a shock to us that somebody had the other half," Viola said in a phone interview from Kyrgyzstan, where he was doing field work.

Geigl offered to show the bone to them and suggested they find some way to publish the information.

"It's pity that nobody knows the no one knows that I'm the only one who has the pictures of this bone in my computer," she recalled telling them.

Viola was keen to see the photos, but quite surprised when he received them.

"This looks very different than what I expected," he recalled, writing in response.

The Denisovans had large, unusual teeth unlike those of humans or Neanderthals. (Bence Viola/University of Toronto)

Based on their huge teeth and a small fragment of skull, he had the impression Denisovans were even heftier and therefore less human-like than Neanderthals: "All of those are very large and robust. They come from huge individuals."

Geigl said the fact the bone looked more human than Neanderthal wasn't really a surprise for her. "Evolution is not something linear. Some features evolve faster than others."

The new finding suggests the knobs on the ends of Neanderthals' fingertips evolved relatively late.

Knobs on the fingertips suggest devolution, not evolution.

Viola combined the images of the two halves to reconstruct of the entire finger. That allowed the researchers to see that based on the growth of the bone, the girl it belonged to was likely a couple of years older than previously thought — about 14 or 15.

Matthew Tocheri, who holds a Canada Research Chair in Human Origins at Lakehead University in Thunder Bay, Ont., and was not involved in the study, said he thought the results were "kind of neat."

Like Geigl, he thought the similarity to humans was not that surprising. He noted modern humans, Neanderthals and Denisovans are all closely related, and, in fact, many Neanderthal and human features are indistinguishable. The fingertips just happen to be one difference.

Similarly, many Denisovans characteristics will likely be very human-like, and we don't yet know their "distinguishing" features, he said.

Tocheri said it was nice to have a bone that could be compared in modern humans, Denisovans and Neanderthals. But he added, "That's one bone out of over 200 elements to the skeleton. So we've got another 199 or so to go."

Complex Human DNA Trail Provides Some Interesting Surprises

Neanderthals & humans interbred 100,000 years ago

At least 5 different species of humans found

By Rebecca Morelle, Science Correspondent, BBC News

Neanderthal recreation   Image copyright ELISABETH DAYNES/SCIENCE PHOTO LIBRARY

Neanderthals may have been breeding with modern humans much earlier than was thought

Traces of human DNA found in a Neanderthal genome suggest that we started mixing with our now-extinct relatives 100,000 years ago.

Previously it had been thought that the two species first encountered each other when modern humans left Africa, about 60,000 years ago.

The research is published in the journal Nature.

Dr Sergi Castellano, from the Max Planck Institute for Evolutionary Anthropology, in Germany, said: "It is significant for understanding the history of modern humans and Neanderthals."

The Neanderthal remains were found in a cave in Siberia copyright BENCE VIOLA

The ancient remains of a female Neanderthal, found in a remote cave in the Altai Mountains in Siberia, are the source of these revelations about the sex lives of our ancestors.

A genetic analysis reveals that portions of human DNA lie within her genome, revealing an interspecies mingling that took place 100,000 years ago.

We really don't know how widespread Neanderthals and early modern 

humans might have been in the regions between Arabia and China at this time

Prof Chris Stringer, Natural History Museum

Earlier research suggested that humans started interbreeding with our heavy-browed, stocky relatives when they migrated out of Africa and began to spread around the world.

As they left the continent, they met - and mingled with - the Neanderthals, who lived across Europe and Asia.

Neanderthal genes from these encounters are found in humans today, and recent studies have shown that these portions of DNA play an integral role in everything from our immune system to our propensity to diseases.

But the latest finding of a flow of genes in the opposite direction, from humans to Neanderthals, suggests such mating was happening thousands of years earlier.

It is not yet clear what impact these genes had on Neanderthals. "The functional significance of this is unclear at the moment," said Dr Castellano.

Neanderthal genes in the humans are found in many Europeans and Asian populations Science Photo Library

However, the findings do shed more light on the history of human migration.

At the moment we simply don't know how these matings happened

Prof Chris Stringer, Natural History Museum

If early humans were having sex with Neanderthals 100,000 years ago, then they must have been doing so outside of Africa because our close relatives were not found there. And this means that they had left Africa before the larger dispersal that took place at least 40,000 years later.

This adds to the idea that early forays out of the continent took place. Other recent evidence includes early human fossils found in Skhul and Qafzeh in Israel, and recent research that suggests people were living in China at least 80,000 years ago.

Commenting on the study Prof Chris Stringer, research leader in human origins, from the Natural History Museum in London, said: "I think that anywhere in southern Asia could theoretically have been the location of this early interbreeding, since we really don't know how widespread Neanderthals and early modern humans might have been in the regions between Arabia and China at this time."

He added: "At the moment we simply don't know how these matings happened and the possibilities range from relatively peaceful exchanges of partners, to one group raiding another and stealing females (which happens in chimps and some modern hunter-gatherers), through to adopting abandoned or orphaned babies.

"Eventually, geneticists should be able to show if the transfer of DNA in either direction was mainly via males, females, or about equal in proportion, but it will need a lot more data before that becomes possible."

Altai Mtns, Siberia/Mongolia

The cave in the Altai Mountains of Siberian in the photo above is actually famous for having housed not only Neanderthals and humans, but also another extinct species called Denisovans. Their history just adds a whole nuther level of confusion to the human genome. This from Wikipedia:

Denisovan or Denisova hominin (pronunciation: /dᵻˈniːsəvə/ dɛ-nee-sə-və) is an extinct species of human in the genus Homo. The species is sometimes given the name Homo sp. Altai, and Homo sapiens ssp. Denisova. In March 2010, scientists announced the discovery of a finger bone fragment of a juvenile female who lived about 41,000 years ago, found in the remote Denisova Cave in the Altai Mountains in Siberia, a cave which has also been inhabited by Neanderthals and modern humans. Two teeth belonging to different members of the same population have since been reported. In November 2015, a tooth fossil containing DNA was reported to have been found and studied.

Genetically distinct DNA

Analysis of the mitochondrial DNA (mtDNA) of the finger bone showed it to be genetically distinct from the mtDNAs of Neanderthals and modern humans. Subsequent study of the nuclear genome from this specimen suggests that Denisovans shared a common origin with Neanderthals, that they ranged from Siberia to South-East Asia, and that they lived among and interbred with the ancestors of some modern humans, with about 3% to 5% of the DNA of Melanesians and Aboriginal Australians deriving from Denisovans. 

Yet another human species

DNA discovered in Spain suggests that Denisovans at some point resided in Western Europe, where Neanderthals were previously thought to be the only inhabitants. A comparison with the genome of a Neanderthal from the same cave revealed significant local interbreeding with local Neanderthal DNA representing 17% of the Denisovan genome, while evidence was also detected of interbreeding with an as yet unidentified ancient human lineage.

This probably has nothing to do with the discovery of 'hobbits', another human species, on an island in Indonesia. Consequently, that means that there were at least 5 different humanoid species in existence at some time or another.

Similar analysis of a toe bone discovered in 2011 is underway, while analysis of DNA from two teeth found in layers different from the finger bone revealed an unexpected degree of mtDNA divergence among Denisovans. In 2013, mitochondrial DNA from a 400,000-year-old hominin femur bone from Spain, which had been seen as either Neanderthal or Homo heidelbergensis, was found to be closer to Denisovan mtDNA than to Neanderthal mtDNA.