Research Shows Genetic Influence of Neanderthals, Denisovans
2023-10-02
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1Neanderthals live on within us.
2These ancient human relatives, and others, called Denisovans, once lived alongside our early Homo sapiens ancestors.
3The groups mixed and had children.
4As a result, some of the Neanderthals and Denisovans live on in our genes.
5And science is starting to show just how much that shapes us.
6Mary Prendergast, a Rice University archeologist, said, "We're now carrying the genetic legacies and learning about what that means for our bodies and our health."
7In the past few months, researchers have linked Neanderthal DNA to a serious hand disease, the shape of people's noses and other human traits.
8They even placed a gene carried by Neanderthals and Denisovans into mice to investigate its effects on biology.
9The researchers found that the gene gave the mice larger heads and an extra rib.
10Much of the human story remains a mystery.
11But Dr. Hugo Zeberg of the Karolinska Institute in Sweden said new technologies and research are helping scientists begin to answer the questions: "Who are we? Where did we come from?"
12And the answers point to a deep reality: We have far more in common with our ancient cousins than we ever thought.
13Until recently, the genetic legacy from ancient humans was invisible.
14But there has been a number of discoveries from ancient DNA, an area of study developed by Nobel Prize winner Svante Paabo.
15He was first in creating a Neanderthal genome.
16Research shows some African populations have almost no Neanderthal DNA, while those from European or Asian backgrounds have up to two percent.
17Denisovan DNA is rarely found in most parts of the world but makes up four to six percent of the DNA of people in Melanesia.
18The Pacific Ocean area extends from New Guinea to the Fiji Islands.
19That may not sound like much, but it adds up: Even though only 100,000 Neanderthals ever lived, "half of the Neanderthal genome is still around, in small pieces scattered around modern humans," said Zeberg, who works closely with Paabo.
20It is also enough to affect us in very real ways. Scientists studying the subject say the DNA can be both helpful and harmful.
21For example, Neanderthal DNA has been linked to autoimmune diseases like Graves' disease and rheumatoid arthritis.
22When Homo sapiens came out of Africa, they had no immunity to diseases in Europe and Asia.
23But, Neanderthals and Denisovans already living there did.
24Chris Stringer is a human evolution researcher at the Natural History Museum in London.
25Stringer said that by mating with Neanderthals and Denisovans, Homo sapiens "got a quick fix to our immune systems, which was good news 50,000 years ago."
26Stringer added, "The result today is, for some people, that our immune systems are oversensitive, and sometimes they turn on themselves."
27In 2020, research by Zeberg and Paabo found that a major genetic risk factor for severe COVID-19 came from Neanderthals.
28"We compared it to the Neanderthal genome and it was a perfect match," Zeberg said.
29The 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.
30Much less is known about our genetic legacy from Denisovans - although some research has linked genes from them to fat processing and better performance at high altitudes.
31Maanasa Raghavan, a human genetics expert at the University of Chicago, said Tibetans carry an amount of Denisovan DNA.
32She noted that the population continues to live and do well in low-oxygen environments today.
33John Hawks of the University of Wisconsin-Madison said that human evolution was not about "survival of the fittest and extinction."
34Instead, he suggested, it is about "interaction and mixture."
35Researchers expect to learn more as the science continues to develop.
36Even when ancient bones are not available, scientists today can get DNA from soil where ancient humans once lived.
37And there are less-explored places in the world where researchers hope to learn more.
38Zeberg said "biobanks" that collect biological materials will likely be established in more countries.
39As researchers go 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.
40"Perhaps," Zeberg said, "we should not see them as so different."
41I'm John Russell.
42And I'm Anna Matteo.
1Neanderthals live on within us. 2These ancient human relatives, and others, called Denisovans, once lived alongside our early Homo sapiens ancestors. The groups mixed and had children. As a result, some of the Neanderthals and Denisovans live on in our genes. And science is starting to show just how much that shapes us. 3Mary Prendergast, a Rice University archeologist, said, "We're now carrying the genetic legacies and learning about what that means for our bodies and our health." 4In the past few months, researchers have linked Neanderthal DNA to a serious hand disease, the shape of people's noses and other human traits. They even placed a gene carried by Neanderthals and Denisovans into mice to investigate its effects on biology. The researchers found that the gene gave the mice larger heads and an extra rib. 5Much of the human story remains a mystery. But Dr. Hugo Zeberg of the Karolinska Institute in Sweden said new technologies and research are helping scientists begin to answer the questions: "Who are we? Where did we come from?" 6And the answers point to a deep reality: We have far more in common with our ancient cousins than we ever thought. 7Neanderthal, Denisovan DNA 8Until recently, the genetic legacy from ancient humans was invisible. But there has been a number of discoveries from ancient DNA, an area of study developed by Nobel Prize winner Svante Paabo. He was first in creating a Neanderthal genome. 9Research shows some African populations have almost no Neanderthal DNA, while those from European or Asian backgrounds have up to two percent. Denisovan DNA is rarely found in most parts of the world but makes up four to six percent of the DNA of people in Melanesia. The Pacific Ocean area extends from New Guinea to the Fiji Islands. 10That may not sound like much, but it adds up: Even though only 100,000 Neanderthals ever lived, "half of the Neanderthal genome is still around, in small pieces scattered around modern humans," said Zeberg, who works closely with Paabo. 11It is also enough to affect us in very real ways. Scientists studying the subject say the DNA can be both helpful and harmful. 12For example, Neanderthal DNA has been linked to autoimmune 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. 13Chris Stringer is a human evolution researcher at the Natural History Museum in London. Stringer said that by mating with Neanderthals and Denisovans, Homo sapiens "got a quick fix to our immune systems, which was good news 50,000 years ago." Stringer added, "The result today is, for some people, that our immune systems are oversensitive, and sometimes they turn on themselves." 14In 2020, research by Zeberg and Paabo found that a major genetic risk factor for severe COVID-19 came from Neanderthals. "We compared it to the Neanderthal genome and it was a perfect match," Zeberg said. 15The 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. 16Much less is known about our genetic legacy from Denisovans - although some research has linked genes from them to fat processing and better performance at high altitudes. Maanasa Raghavan, a human genetics expert at the University of Chicago, said Tibetans carry an amount of Denisovan DNA. She noted that the population continues to live and do well in low-oxygen environments today. 17Human evolution 18John Hawks of the University of Wisconsin-Madison said that human evolution was not about "survival of the fittest and extinction." Instead, he suggested, it is about "interaction and mixture." 19Researchers expect to learn more as the science continues to develop. Even when ancient bones are not available, scientists today can get DNA from soil where ancient humans once lived. 20And there are less-explored places in the world where researchers hope to learn more. Zeberg said "biobanks" that collect biological materials will likely be established in more countries. 21As researchers go 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. 22"Perhaps," Zeberg said, "we should not see them as so different." 23I'm John Russell. 24And I'm Anna Matteo. 25Laura Ungar and Maddie Burakoff reported on this story for the Associated Press. 26________________________________________________ 27Words in This Story 28legacy - n. something that comes from someone in the past 29trait - n. a quality that makes one person or thing different from another 30genome - n. the complete set of genetic material present in an organism 31scatter - v. to cause (things or people) to go in different directions 32variant - n. something that is different in some way from others of the same kind