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How do we know Neanderthals DNA?

How do we know Neanderthals DNA?


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According to this article, a small amount of Neanderthal DNA was introduced into the modern human gene pool. How do biologists even know what the Neanderthals' DNA look like?

The article doesn't mention how the science recognize what the Neanderthals' DNA actually is at the first place. So how do we know what the Neanderthals' DNA is if I'm guessing we never tested Neanderthals body cell samples?

If you say "From their bones/skull" but how do you know they are actually Neanderthals and not modern humans with some rare gene mutation or something else?


Neandertal DNA has been completely sequenced multiple times now, using DNA from bone and tooth samples found in cool or cold environments. The first Neanderthal genome sequence was described in 2010:

A Draft Sequence of the Neandertal Genome

Since then, as well as higher-quality sequence, more genomes have been completed; at least 6 individuals have been sequenced (perhaps more; I've lost track a little). As well, complete genome sequences from several Denisovans -- a Homo species that were approximately contemporary with Neandertals, but a distinct species -- have been recovered.

The science of recovering ancient DNA has advanced very rapidly in the last decade, and while it isn't routine to sequence 50,000-year-old DNA it isn't as magical as it used to be. The current record for sequencing ancient DNA is 700,000 years, which is earlier than the sapiens/neandertalis split.


The answers here give you reference to the first draft genome. Take a look at these papers for high-quality sequences: Prufer et al., 2014 for Altai Neandertal, Meyer et al., 2012 for the Denisova individual. A third one, the Vindija Neandertal has been sequenced and the sequence is already available (though not published, yet) here. However, one thing has not been mentioned. The presence of ancient DNA can be confirmed by identifying specific damage patterns in the DNA molecules, i.e. mainly deamination. That is used to ensure that the DNA is old and does not result from contamination of present-day humans. Additionally, modern human contamination levels are estimated by two or three independent methods in the papers given above. These methods exploit the uniqueness of Neandertal mitochondria and Y-chromosomes, i.e. the fact that these variants have never been seen in present-day humans.

This answers the sequence part, but my answer focuses on the second part of your question and the issue your raise in the comment sections:

If you say "From their bones/skull" but how do you know they are actually Neanderthals and not Humans with some rare gene mutation or something else?

This can mainly be answered on two different levels. The first level is a parsimony argument: there are a lot of those skeletons (far more than the ones that have been sequenced) and it would be too unlikely they all suffered from the same disease. Additionally, skeletons of present-day humans with the diseases you mention do not at all look like Neandertal skeletons.

The second level is a bit more scientific: bones from the spanish cave Sima de los Huesos have been sequenced as well (Meyer et al. (2014) for a mitochondrial genome and Meyer et al. (2016) for nuclear sequences - not full genome!). Bones from this cave has been dated to approx 430,000 years ago which means that those bones may not even be Neandertal bones but rather Homo heidelbergensis. This makes a strong point against your suspicion as at that times modern humans did not even exist anywhere on the planet and it took another about 200,000 years until the first anatomically modern humans evolved in Africa (and then another 150,000 years until they set foot to Europe).


The sequence of the neanderthal genome is known because it has been sequenced and could then be compared to the human reference genome. The DNA was extracted from a toe bone found in Siberia, as described in reference 1.

The sequencing was done as described in reference 2. The researchers where sure that the bones came from Neanderthals because of anthropologic differences in the built of the bones they found. They are distinct from homo sapiens bones.

References:

  1. A proximal pedal phalanx of a Paleolithic hominin from denisova cave, Altai
  2. A Draft Sequence of the Neandertal Genome

20 Things You Didn't Know About . Neanderthals

1. You’re pretty much a Neanderthal. While it’s been more than 5 million years since we parted ways with chimps, it has been only 400,000 since human and Neanderthal lineages split.

2. If you’re Asian or Caucasian, your ancestors interbred with Neanderthals as recently as 37,000 years ago, when they crossed paths in Europe.

3. And that sex had benefits. Inherited Neanderthal genes come in alleles that help fight off nasty viruses such as Epstein-Barr — associated with several kinds of cancer, says Stanford University immunologist Laurent Abi-Rached.

4. If you want to know how much Neanderthal DNA you carry, just swab your cheek and send it to the National Geographic Society’s Genographic Project. Or you could have your entire genome sequenced as Ozzy Osbourne did in 2010. Researchers found a telltale Neanderthal segment on his chromosome 10.

5. Now that the whole Neanderthal genome has been sequenced, Harvard geneticist George Church thinks a clone could be gestated in a human surrogate mother. It could even be beneficial, he believes, because the Neanderthal mind might be able to solve problems we can’t.

6. Practically nobody believed you could read a Neanderthal’s genes until 2010, when the paleogeneticist Svante Pääbo successfully sequenced DNA from three Neanderthal skeletons found in Croatia.

7. The first evidence of Neanderthals was discovered in 1856. Miners in Germany’s Neander Valley found fossils thought to belong to a cave bear. A local natural historian begged to differ. He reckoned the strange bones were the remains of a lost Cossack suffering from rickets.

8. Charles Darwin published On the Origin of Species three years later. In the context of Darwin’s theories of evolution, the bones were re-examined by anatomist William King, who promptly named them Homo neanderthalensis , a name that provocatively (and incorrectly) suggested they were the missing link between apes and humans.

9. As late as the mid-1970s, creationists were still claiming Neanderthal fossils were the remains of modern humans with acromegaly or arthritis.

10. Paleontologist Marcellin Boule would have been well advised to study pathology. Between 1909 and 1911, he reconstructed the first skeleton of a Neanderthal — who happened to be arthritic. Thus was born the degenerate, slouching image of Neanderthals.

11. They were the ultimate craftsmen, able to pick up impressive skills through practice, but none too creative, say anthropologist Thomas Wynn and psychologist Frederick L. Coolidge of the University of Colorado at Colorado Springs.

12. Credit Neanderthals with a couple of great ideas: They made spears by hafting stone points to wooden shafts, and bonding them with glue.

13. They threw those spears at bison and woolly rhinoceros, resulting in hunting injuries that would end the career of a linebacker.

14. Not that a maimed Neanderthal could afford to retire. Instead they nursed each other back to health, enlisting their greatest concept of all: empathy.

15. They also had medicine. Traces of chamomile and yarrow, two anti-inflammatories, have been detected in the plaque on Neanderthal teeth.

16. Or are these pungent traces of haute cuisine? Neanderthals balanced their carnivorous diets with vegetables roasted over smoky fires.

17. And they had a sense of style. Archaeologists have recovered a yellow pigment in southern Spain that may have been used as foundation for their skin.

18. Evidently Spain was the place to be if you were a Neanderthal with cultural pretensions. Last summer, paintings in El Castillo Cave on the Pas River were found to be at least 40,800 years old.

19. They were better painters than talkers. The anatomy of their vocal tracts would have prevented them from sounding some vowels.

20. In any case, we lost our chance at conversation, since they died out some 25,000 years ago. Their last refuge was Gibraltar, now a haven for tax evaders.


What Neanderthals were like

Many modern humans hate winter for a reason: We aren't adapted to the cold. Some peoples have made their homes in freezing climates, but as a species, we didn't evolve for it. Neanderthals, on the other hand, were cold-weather humans who through evolution adapted to some of the harshest climates the Ice Age Earth presented. This in turn made them look a bit different from us. Honestly, if you were standing right next to a Neanderthal, you probably wouldn't notice. To you, they'd just look like an oddly proportioned modern human.

Meet great-grandpappy Ned the Neanderthal. Ned is short. He stands about 5' 2", but that's not bad for a Neanderthal. The tallest were only around 5' 5" or so. Ned's stubby legs and short arms don't help with his height, but, as The Natural History Museum, London, points out, they do help prevent frostbite and hypothermia.

After his height, one of the first things you might notice about Ned is that he's ripped. Neanderthals were thick and muscular, like tiny circus strongmen, which helped with ambush hunting great beasts like the woolly rhino. To our eyes, Ned looks a little goofy, with his giant schnoz, weak chin, protruding brow, and buck teeth, but don't think for a second that Ned is stupid. He can make tools and art with the best of them. He does come from a time before showers, however, so you might want to stay back a few steps.


Africans carry surprising amount of Neanderthal DNA

For 10 years, geneticists have told the story of how Neanderthals—or at least their DNA sequences—live on in today’s Europeans, Asians, and their descendants. Not so in Africans, the story goes, because modern humans and our extinct cousins interbred only outside of Africa. A new study overturns that notion, revealing an unexpectedly large amount of Neanderthal ancestry in modern populations across Africa. It suggests much of that DNA came from Europeans migrating back into Africa over the past 20,000 years.

“That gene flow with Neanderthals exists in all modern humans, inside and outside of Africa, is a novel and elegant finding,” says anthropologist Michael Petraglia of the Max Planck Institute for the Science of Human History. The work, reported in this week’s issue of Cell, could also help clear up a mysterious disparity: why East Asians appear to have more Neanderthal ancestry than Europeans.

As members of Homo sapiens spread from Africa into Eurasia some 70,000 years ago, they met and mingled with Neanderthals. Researchers knew that later back-migrations of Europeans had introduced a bit of Neanderthal DNA into African populations, but previous work suggested it was a just a smidgen. In contrast, modern Europeans and East Asians apparently inherited about 2% of their DNA from Neanderthals.

Previous efforts simply assumed that Africans largely lacked Neanderthal DNA. To get more reliable numbers, Princeton University evolutionary biologist Joshua Akey compared the genome of a Neanderthal from Russia’s Altai region in Siberia, sequenced in 2013, to 2504 modern genomes uploaded to the 1000 Genomes Project, a catalog of genomes from around the world that includes five African subpopulations. The researchers then calculated the probability that each stretch of DNA was inherited from a Neanderthal ancestor.

The researchers found that African individuals on average had significantly more Neanderthal DNA than previously thought—about 17 megabases (Mb) worth, or 0.3% of their genome. They also found signs that a handful of Neanderthal genes may have been selected for after they entered Africans’ genomes, including genes that boost immune function and protect against ultraviolet radiation.

The results jibe with as-yet-unpublished work by Sarah Tishkoff, an evolutionary geneticist at the University of Pennsylvania. She told Science she has also found higher-than-expected levels of apparent Neanderthal DNA in Africans.

The best fit model for where Africans got all this Neanderthal DNA suggests about half of it came when Europeans—who had Neanderthal DNA from previous matings—migrated back to Africa in the past 20,000 years. The model suggests the rest of the DNA shared by Africans and the Altai Neanderthal might not be Neanderthal at all: Instead, it may be DNA from early modern humans that was simply retained in both Africans and Eurasians—and was picked up by Neanderthals, perhaps when moderns made a failed migration from Africa to the Middle East more than 100,000 years ago.

Akey’s study might help explain another “head scratcher,” says computer biologist Kelley Harris of the University of Washington, Seattle. Studies had suggested East Asians have 20% more Neanderthal DNA than Europeans, she notes. “Europe is where Neanderthal remains are found, so why wouldn’t Europeans have more Neanderthal ancestry than any other group?”

By suggesting that Europeans introduced Neanderthal sequences into Africa, the new study points to an explanation: Researchers previously assumed that Neanderthal sequences shared by Europeans and Africans were modern and subtracted them out. After correcting for that bias, the new study found similar amounts of Neanderthal DNA in Europeans and Asians—51 and 55 Mb, respectively. It’s a “convincing and elegant” explanation, Harris says.


DNA Evidence Shows Early Humans Mated with Neanderthals in Europe

Genetic analysis of the mandible of an anatomically modern Homo sapiens who lived in what is now Romania between 42,000 and 37,000 years ago reveals that early humans interbred with Neanderthals when they first came to Europe.

This image shows a Neanderthal man. Image credit: Mauro Cutrona.

Neanderthals are thought to have disappeared in Europe around 39,000 – 41,000 years ago but they have contributed up to 3 percent of the DNA of present-day Eurasians.

“We know that before 45,000 years ago, the only humans in Europe were Neanderthals. After 35,000 years ago, the only humans in Europe were modern humans. This is a dramatic transition,” explained Dr David Reich of Howard Hughes Medical Institute and the Broad Institute of MIT and Harvard, who is a co-lead author of the paper discussing the results in the journal Nature.

There is evidence that anatomically modern humans interacted with Neanderthals during the time that they both lived in Europe: changes in tool making technology, burial rituals, and body decoration imply a cultural exchange between the groups.

But archaeologists have very few skeletons from this period. So the 40,000-year-old human jawbone that archaeologists unearthed in 2002 in the Peştera cu Oase cave in south-western Romania was an important find.

The mandible was found along with the skull of another individual. No artifacts were discovered nearby, so scientists had no cultural clues about who the individuals were or how they lived.

The physical features of the mandible were predominantly those of anatomically modern humans, but some Neanderthal traits were also apparent, and the scientists proposed that the bone might have belonged to someone descended from both groups.

Dr Reich and his colleagues from Canada, the United States, China, Germany and Romania, have now analyzed DNA from the mandible and found that on the order of 6 – 9 percent of the genome of the Oase individual is derived from Neanderthals, more than any other modern human sequenced to date.

“It’s an incredibly unexpected thing. In the last few years, we’ve documented interbreeding between Neanderthals and modern humans, but we never thought we’d be so lucky to find someone so close to that event,” Dr Reich said.

The scientists also estimated that the Oase man had a Neanderthal ancestor in the previous four to six generations.

“Three chromosomal segments of Neanderthal ancestry are over 50 centimorgans in size, indicating that this individual had a Neanderthal ancestor as recently as four to six generations back,” they said.

“The data from the jawbone imply that humans mixed with Neanderthals not just in the Middle East but in Europe as well,” said study first author Dr Qiaomei Fu from the Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences.

However, the Oase individual is not responsible for passing his Neanderthal ancestry on to present day humans.

“It may be that he was part of an early migration of modern humans to Europe that interacted closely with Neanderthals but eventually became extinct,” Dr Reich explained.

Qiaomei Fu et al. An early modern human from Romania with a recent Neanderthal ancestor. Nature, published online June 22, 2015 doi: 10.1038/nature14558


Our Hominin Ancestors

Research into ancient humans got a big boost around a decade ago, when scientists first sequenced the genomes of Neanderthals and Denisovans . For the first time, anthropologists were able to compare the genomes of both H. sapiens and other ancient humans to look for similarities. The evidence revealed clear signs of interbreeding — the human genome can contain stretches of DNA that match strongly with both the Neanderthal and Denisovan genomes.

While we know that humans contain DNA from both Neanderthals and Denisovans, the amounts vary. People whose ancestors come from Europe and Asia received about two percent of their DNA from Neanderthals. Denisovan DNA, by contrast, shows up only in people from Asia, where it can make up anywhere from a few to around five percent of their genomes.

Africans were long thought not to have any DNA from Neanderthals or Denisovans, as ancient humans acquired those genes only after leaving Africa. But a 2020 study picked out small amounts of Neanderthal DNA in people from Africa, contrary to that long-held assumption. It likely came from humans moving back to Africa from Europe or elsewhere, the authors say.

New fossils have also helped fill out the story in recent years. In 2018, scientists announced they’d found remains belonging to a young girl who was a Neanderthal-Denisovan hybrid . The specimen, called “Denisova 11” had a Neanderthal mother and a Denisovan father, and lived more than 50,000 years ago. A 2021 paper analyzing the oldest human DNA to date , found in Bacho Kiro cave in Bulgaria and dating to about 45,000 years ago, indicated the individuals had Neanderthal ancestors just a few generations back.

Comparisons of modern-day human DNA with the Denisovan genome have similarly indicated that our ancestors interbred with the ancient hominins. Studies of people of Asian and Pacific Islander descent today reveal Denisovan DNA in their genomes. Scientists think their ancestors intermingled with Denisovans sometime after migrating to the region tens of thousands of years ago. Those genes have proven beneficial in some cases. An analysis of a Denisovan jawbone found in a cave high on the Tibetan plateau revealed that modern-day Tibetans harbor a key gene, inherited from Denisovans, that allows their bodies to better deal with the punishing effects of altitude.

Genes from Neanderthals have also been linked to how our skins react to UV light, depression, allergies, myocardial infarctions and other conditions. As we come to better understand both our own and other hominins’ DNA, we’ll likely discover more.


Neanderthal DNA has subtle but significant impact on human traits

Neanderthal DNA influences many physical traits in people of Eurasian heritage. Credit: Michael Smeltzer, Vanderbilt University

Since 2010 scientists have known that people of Eurasian origin have inherited anywhere from 1 to 4 percent of their DNA from Neanderthals.

The discovery spawned a number of hypotheses about the effects these genetic variants may have on the physical characteristics or behavior of modern humans, ranging from skin color to heightened allergies to fat metabolism. generating dozens of colorful headlines including "What your Neanderthal DNA is doing for you" and "Neanderthals are to blame for our allergies" and "Did Europeans Get Fat From Neanderthals?"

Now, the first study that directly compares Neanderthal DNA in the genomes of a significant population of adults of European ancestry with their clinical records confirms that this archaic genetic legacy has a subtle but significant impact on modern human biology.

"Our main finding is that Neanderthal DNA does influence clinical traits in modern humans: We discovered associations between Neanderthal DNA and a wide range of traits, including immunological, dermatological, neurological, psychiatric and reproductive diseases," said John Capra, senior author of the paper "The phenotypic legacy of admixture between modern humans and Neanderthals" published in the Feb. 12 issue of the journal Science. The evolutionary geneticist is an assistant professor of biological sciences at Vanderbilt University.

Neanderthal-influenced traits. Credit: Deborah Brewington, Vanderbilt University

Some of the associations that Capra and his colleagues found confirm previous hypotheses. One example is the proposal that Neanderthal DNA affects cells called keratinocytes that help protect the skin from environmental damage such as ultraviolet radiation and pathogens. The new analysis found Neanderthal DNA variants influence skin biology in modern humans, in particular the risk of developing sun-induced skin lesions called keratosis, which are caused by abnormal keratinocytes.

In addition, there were a number of surprises. For example, they found that a specific bit of Neanderthal DNA significantly increases risk for nicotine addiction. They also found a number of variants that influence the risk for depression: some positively and some negatively. In fact, a surprisingly number of snippets of Neanderthal DNA were associated with psychiatric and neurological effects, the study found.

"The brain is incredibly complex, so it's reasonable to expect that introducing changes from a different evolutionary path might have negative consequences," said Vanderbilt doctoral student Corinne Simonti, the paper's first author.

According to the researchers, the pattern of associations that they discovered suggest that today's population retains Neanderthal DNA that may have provided modern humans with adaptive advantages 40,000 years ago as they migrated into new non-African environments with different pathogens and levels of sun exposure. However, many of these traits may no longer be advantageous in modern environments.

Credit: Michael Smeltzer, Vanderbilt University

One example is a Neanderthal variant that increases blood coagulation. It could have helped our ancestors cope with new pathogens encountered in new environments by sealing wounds more quickly and preventing pathogens from entering the body. In modern environments this variant has become detrimental, because hypercoagulation increases risk for stroke, pulmonary embolism and pregnancy complications.

In order to discover these associations, the researchers used a database containing 28,000 patients whose biological samples have been linked to anonymized versions of their electronic health records. The data came from eMERGE - the Electronic Medical Records and Genomics Network funded by the National Human Genome Research Institute - which links digitized records from Vanderbilt University Medical Center's BioVU databank and eight other hospitals around the country.

This data allowed the researchers to determine if each individual had ever been treated for a specific set of medical conditions, such as heart disease, arthritis or depression. Next they analyzed the genomes of each individual to identify the unique set of Neanderthal DNA that each person carried. By comparing the two sets of data, they could test whether each bit of Neanderthal DNA individually and in aggregate influences risk for the traits derived from the medical records.

"Vanderbilt's BioVU and the network of similar databanks from hospitals across the country were built to enable discoveries about the genetic basis of disease," said Capra. "We realized that we could use them to answer important questions about human evolution."

According to the evolutionary geneticist, this work establishes a new way to investigate questions about the effects of events in recent human evolution.

The current study was limited to associating Neanderthal DNA variants with physical traits (phenotypes) included in hospital billing codes, but there is a lot of other information contained in the medical records, such as lab tests, doctors' notes, and medical images, that Capra is working on analyzing in a similar fashion.


How do we know Neanderthals DNA? - Biology

By analyzing whole-genome sequencing data from 665 people from Europe and East Asia as part of the 1,000 Genomes Project, researchers have determined that more than 20 percent of the Neanderthal genome survives in the DNA of this contemporary group.

That means a substantial fraction of the Neanderthal genome persists in modern human populations. Neanderthals became extinct about 30,000 years ago but their time on earth and their geographic range overlapped with us.

Previous research proposed that someone of non-African descent may have inherited approximately 1 percent to 3 percent of their genome from Neanderthal ancestors. The new findings are a start to identifying the location of specific pieces of Neanderthal DNA in modern humans and a beginning to creating a collection of Neanderthal lineages surviving in present-day human populations.

To check the accuracy of their approach, Benjamin Vernot and Joshua Akey of the University of Washington ran their analysis before comparing the suspected Neanderthal sequences they found in modern humans to the recently mapped Neanderthal genome obtained from DNA recovered from bone. This genome came from the paleogenetics laboratory of Svante Paabo of the Max Planck Institute for Evolutionary Anthropology in Germany.

"We wanted to know how well our predictions matched the Neanderthal reference genome," Akey said. "The analysis showed that, after more refinement of these methods, scientists might not need a reference genome from an archaic species to do this type of study."

The results suggest that significant amounts of population-level DNA sequences might be obtained from extinct groups even in the absence of fossilized remains, because these ancient sequences might have been inherited by other individuals from whom scientists can gather genomic data, according to Akey. Therein lies the potential to discover and characterize previously unknown archaic humans that bred with early humans.

"In the future, I think scientists will be able to identify DNA from other extinct hominin, just by analyzing modern human genomes," Vernot said. "From our end, this was an entirely computational project. I think it's really interesting how careful application of the correct statistical and computational tools can uncover important aspects of health, biology and human history. Of course, you need good data, too."

Joshua Akey (left) and Benjamin Vernot (right). Credit: Clare McLean/University of Washington

The two closely related groups mated and produced some fertile offspring, such that portions of Neanderthal DNA were passed along to the next generations. In a proposed model, this mixing of DNA could have occurred both before and after the evolutionary divergence of non-African modern humans from a common ancestral population.

It didn't necessarily take a lot of individual hybrid offspring to introduce Neanderthal genes into early human populations. Still, Akey said that it isn't known how many Neanderthal ancestors present-day humans have.

But past interactions between the groups, Akey noted, is probably more complicated than previously thought.

"In addition, the analysis of surviving archaic lineages points to the possibility that there were fitness costs to the hybridization of Neanderthal and humans," Akey said.

"I think what was most surprising to me," Vernot noted, "is that we found evidence of selection. Last year, I would have bet that a Neanderthal/human hybrid would have been as fit as a fully modern human. This was mostly because we haven't been separated from them that long, on an evolutionary scale."

Nevertheless, the Neanderthals were also a probable source for at least a few genetic variations that were adaptive for their human descendants. Neanderthal DNA sequences are found in regions of the genome that have been linked to the regulation of skin pigmentation. The acquisition of these variants by mating with the Neanderthals may have proven to be a rapid way for humans to adapt to local conditions.

"We found evidence that Neanderthal skin genes made Europeans and East Asians more evolutionarily fit," Vernot said, "and that other Neanderthal genes were apparently incompatible with the rest of the modern human genome, and thus did not survive to present day human populations."

The researchers observed that certain chromosomes arms in humans are tellingly devoid of Neanderthal DNA sequences, perhaps due to mismatches between the two species along certain portions of their genetic materials. For example, they noticed a strong depletion of Neanderthal DNA in a region of human genomes that contains a gene for a factor thought to play an important role in human speech and language.

According to the scientists, the "fossil free" method of sequencing archaic genomes not only holds promise in revealing aspects of the evolution of now-extinct archaic humans and their characteristic population genetics, it also might provide insights into how interbreeding influenced current patterns of human diversity.

Additionally, such studies might also help researchers hone in on genetic changes not found in any other species, and learn if these changes helped endow early people with uniquely human attributes.


Mysterious relatives

Scientists have long speculated about Neanderthals’ relationships to modern humans. While the exact question shifted over the years, it’s a debate that goes back to Neanderthals’ initial discovery, says John Hawks, a paleoanthropologist at the University of Wisconsin-Madison who was not involved in the study.

In the last several decades, however, the driving question turned to mixing with modern humans. Did these two hominins interbreed. In 2010, with the first publication of a Neanderthal whole genome, scientists finally had an answer: Yes.

Comparison of Neanderthal DNA to five living humans revealed that Europeans and Asians—but not Africans—carried traces of interbreeding. Studies since have hinted at some limited Neanderthal ancestry in Africa, but no one has fully traced these tangled branches of our family tree. (Read more about the many lines of mysterious ancient humans that interbred with us.)

For a fresh look at this genetic mixing, Akey and his team developed a new way to study the scattering of ancient hominin DNA in modern genomes. All models tackling this question must not only identify shared genetic sequences, but they also have to figure out what makes it similar because not all shared genetic code is the result of interbreeding. Some DNA could be similar thanks to a common hominin ancestor.

Many models tracing Neanderthal interbreeding use what’s known as a reference population—the genomes from a group, usually from Africa, that’s assumed to not have DNA from these ancient hominins.

“That assumption was never reasonable,” Hawks says. By setting up a model in this way, these analyses hide potential Neanderthal ancestry for people of African descent.

Instead, Akey and his lab used large datasets to examine the probability that a particular site in the genome was inherited from Neanderthals or not. They tested the method with the genomes of 2,504 individuals from around the world—East Asians, Europeans, South Asians, Americans, and largely northern Africans—collected as part of the 1000 Genomes project. They then compared this DNA with a Neanderthal genome.


2 thoughts on &ldquo Neanderthal DNA: How different were they from humans? &rdquo

Your blog combines both biological anthropology and archaeology to reveal insights into early human populations. American Anthropology is often separated into four fields: linguistical anthropology, cultural anthropology, biological anthropology, and archaeology. Why does having so many subfields matter? What impact does it have on anthropology as a field?

Anthropology is the study of humans, human behaviors and societies, both in the past and the present. Hence the field encompasses a variety of concentrations which focus on different aspects of human lives. Linguistic anthropology seeks to understand the processes of human communication cultural anthropology is the study of cultural variation among humans biological (or physical) anthropology is concerned with the biological and behavioral aspects of humans and archaeology is the study of the human past through its material remains. Each field has further subfields too. Having so many subfields makes anthropology such that two different anthropologists may have completely different and unrelated courses of research. However, they are still connected by their interest in deciphering what it means to be human.



Comments:

  1. Moogugis

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