There is evidence showing that an early variant hit the human race about 20,000
years ago. Eric
PLAY THE
CROSSWORD<https://www.nytimes.com/subscription/games/lp8J6KQ?campaignId=6F88R>
Account
<https://www.nytimes.com/section/science>
<https://www.nytimes.com/><https://www.nytimes.com/>
*
*
*
*
ADVERTISEMENT
Continue reading the main
story<https://www.nytimes.com/2021/06/24/science/ancient-coronavirus-epidemic.html?action=click&algo=bandit-all-surfaces&block=trending_recirc&fellback=false&imp_id=812686856&impression_id=30fa870e-d535-11eb-a15d-6dd6396f9409&index=2&pgtype=Article&pool=pool%2F91fcf81c-4fb0-49ff-bd57-a24647c85ea1®ion=footer&req_id=935318571&surface=most-popular-story&variant=0_bandit-all-surfaces#after-top>
MATTER
A Coronavirus Epidemic Hit 20,000 Years Ago, New Study Finds
A few dozen human genes rapidly evolved in ancient East Asia to thwart
coronavirus infections, scientists say. Those genes could be crucial to today’s
pandemic.
*
<https://www.facebook.com/dialog/feed?app_id=9869919170&link=https%3A%2F%2Fwww.nytimes.com%2F2021%2F06%2F24%2Fscience%2Fancient-coronavirus-epidemic.html%3Fsmid%3Dfb-share&name=A%20Coronavirus%20Epidemic%20Hit%2020%2C000%20Years%20Ago%2C%20New%20Study%20Finds&redirect_uri=https%3A%2F%2Fwww.facebook.com%2F>
*
<https://api.whatsapp.com/send?text=A%20Coronavirus%20Epidemic%20Hit%2020%2C000%20Years%20Ago%2C%20New%20Study%20Finds%20https%3A%2F%2Fwww.nytimes.com%2F2021%2F06%2F24%2Fscience%2Fancient-coronavirus-epidemic.html%3Fsmid%3Dwa-share>
*
<https://twitter.com/intent/tweet?url=https%3A%2F%2Fwww.nytimes.com%2F2021%2F06%2F24%2Fscience%2Fancient-coronavirus-epidemic.html%3Fsmid%3Dtw-share&text=A%20Coronavirus%20Epidemic%20Hit%2020%2C000%20Years%20Ago%2C%20New%20Study%20Finds>
*
<mailto:?subject=NYTimes.com%3A%20A%20Coronavirus%20Epidemic%20Hit%2020%2C000%20Years%20Ago%2C%20New%20Study%20Finds&body=From%20The%20New%20York%20Times%3A%0A%0AA%20Coronavirus%20Epidemic%20Hit%2020%2C000%20Years%20Ago%2C%20New%20Study%20Finds%0A%0AA%20few%20dozen%20human%20genes%20rapidly%20evolved%20in%20ancient%20East%20Asia%20to%20thwart%20coronavirus%20infections%2C%20scientists%20say.%20Those%20genes%20could%20be%20crucial%20to%20today%E2%80%99s%20pandemic.%0A%0Ahttps%3A%2F%2Fwww.nytimes.com%2F2021%2F06%2F24%2Fscience%2Fancient-coronavirus-epidemic.html%3Fsmid%3Dem-share>
*
*
*
* 34
[https://static01.nyt.com/images/2021/06/24/science/24-ancient-virus/24-ancient-virus-articleLarge.jpg?quality=75&auto=webp&disable=upscale]
[https://static01.nyt.com/images/2021/06/24/science/24-ancient-virus/24-ancient-virus-articleLarge.jpg?quality=75&auto=webp&disable=upscale]
Credit...Sercomi/Science Source
[Carl Zimmer]<https://www.nytimes.com/by/carl-zimmer>
By Carl Zimmer<https://www.nytimes.com/by/carl-zimmer>
June 24, 2021, 11:00 a.m. ET
Researchers have found evidence that a coronavirus epidemic swept East Asia
some 20,000 years ago and was devastating enough to leave an evolutionary
imprint on the DNA of people alive today.
SIGN UP FOR SCIENCE TIMES: Get stories that capture the wonders of nature, the
cosmos and the human body.
Sign Up
The new study<https://doi.org/10.1016/j.cub.2021.05.067> suggests that an
ancient coronavirus plagued the region for many years, researchers say. The
finding could have dire implications for the Covid-19 pandemic if it’s not
brought under control soon through vaccination.
“It should make us worry,” said David Enard, an evolutionary biologist at the
University of Arizona who led the study, which was published on Thursday in the
journal Current Biology. “What is going on right now might be going on for
generations and generations.”
Until now, researchers could not look back very far into the history of this
family of pathogens. Over the past 20 years, three coronaviruses have adapted
to infect humans and cause severe respiratory disease: Covid-19, SARS and MERS.
Studies on each of these coronaviruses indicate that they jumped into our
species from bats or other mammals.
ADVERTISEMENT
Continue reading the main
story<https://www.nytimes.com/2021/06/24/science/ancient-coronavirus-epidemic.html?action=click&algo=bandit-all-surfaces&block=trending_recirc&fellback=false&imp_id=812686856&impression_id=30fa870e-d535-11eb-a15d-6dd6396f9409&index=2&pgtype=Article&pool=pool%2F91fcf81c-4fb0-49ff-bd57-a24647c85ea1®ion=footer&req_id=935318571&surface=most-popular-story&variant=0_bandit-all-surfaces#after-story-ad-1>
Four other coronaviruses can also infect people, but they usually cause only
mild colds. Scientists did not directly observe these coronaviruses becoming
human pathogens, so they have relied on indirect clues to estimate when the
jumps happened. Coronaviruses gain new mutations at a roughly regular rate, and
so comparing their genetic variation makes it possible to determine when they
diverged<https://www.cell.com/trends/microbiology/fulltext/S0966-842X(16)30133-0?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0966842X16301330%3Fshowall%3Dtrue>
from a common ancestor.
The most recent of these mild coronaviruses, called HCoV-HKU1, crossed the
species barrier in the 1950s. The oldest, called HCoV-NL63, may date back as
far as 820 years.
But before that point, the coronavirus trail went cold — until Dr. Enard and
his colleagues applied a new method to the search. Instead of looking at the
genes of the coronaviruses, the researchers looked at the effects on the DNA of
their human hosts.
Over generations, viruses drive enormous amounts of change in the human genome.
A mutation that protects against a viral infection may well mean the difference
between life and death, and it will be passed down to offspring. A lifesaving
mutation, for example, might allow people to chop apart a virus’s proteins.
But viruses can evolve, too. Their proteins can change shape to overcome a
host’s defenses. And those changes might spur the host to evolve even more
counteroffensives, leading to more mutations.
Editors’ Picks
<https://www.nytimes.com/2021/06/24/style/abandoned-houses-instagram.html?action=click&algo=identity&block=editors_picks_recirc&fellback=false&imp_id=671455917&impression_id=83214230-d535-11eb-8778-77cc14b105e1&index=0&pgtype=Article&pool=editors-picks-ls®ion=ccolumn&req_id=479747553&surface=home-featured&variant=0_identity&action=click&module=editorContent&pgtype=Article®ion=CompanionColumn&contentCollection=Trending>
The Abandoned Houses of Instagram
<https://www.nytimes.com/interactive/2021/06/24/realestate/24hunt-koszer.html?action=click&algo=identity&block=editors_picks_recirc&fellback=false&imp_id=589139616&impression_id=83214231-d535-11eb-8778-77cc14b105e1&index=1&pgtype=Article&pool=editors-picks-ls®ion=ccolumn&req_id=479747553&surface=home-featured&variant=0_identity&action=click&module=editorContent&pgtype=Article®ion=CompanionColumn&contentCollection=Trending>
Seeking a House in the Bronx for $600,000. Which Option Would You Choose?
<https://www.nytimes.com/2021/06/24/nyregion/orthodox-jewish-mother-medical-school.html?action=click&algo=identity&block=editors_picks_recirc&fellback=false&imp_id=489609618&impression_id=83214232-d535-11eb-8778-77cc14b105e1&index=2&pgtype=Article&pool=editors-picks-ls®ion=ccolumn&req_id=479747553&surface=home-featured&variant=0_identity&action=click&module=editorContent&pgtype=Article®ion=CompanionColumn&contentCollection=Trending>
‘The Rabbi Said It Was OK’: Hasidic Mother of 10 Becomes Doctor
Continue reading the main
story<https://www.nytimes.com/2021/06/24/science/ancient-coronavirus-epidemic.html?action=click&algo=bandit-all-surfaces&block=trending_recirc&fellback=false&imp_id=812686856&impression_id=30fa870e-d535-11eb-a15d-6dd6396f9409&index=2&pgtype=Article&pool=pool%2F91fcf81c-4fb0-49ff-bd57-a24647c85ea1®ion=footer&req_id=935318571&surface=most-popular-story&variant=0_bandit-all-surfaces&action=click&module=editorContent&pgtype=Article®ion=CompanionColumn&contentCollection=Trending#after-pp_edpick>
ADVERTISEMENT
Continue reading the main
story<https://www.nytimes.com/2021/06/24/science/ancient-coronavirus-epidemic.html?action=click&algo=bandit-all-surfaces&block=trending_recirc&fellback=false&imp_id=812686856&impression_id=30fa870e-d535-11eb-a15d-6dd6396f9409&index=2&pgtype=Article&pool=pool%2F91fcf81c-4fb0-49ff-bd57-a24647c85ea1®ion=footer&req_id=935318571&surface=most-popular-story&variant=0_bandit-all-surfaces#after-story-ad-2>
When a random new mutation happens to provide resistance to a virus, it can
swiftly become more common from one generation to the next. And other versions
of that gene, in turn, become rarer. So if one version of a gene dominates all
others in large groups of people, scientists know that is most likely a
signature of rapid evolution in the past.
In recent
years<https://www.nytimes.com/2018/10/04/science/neanderthal-genes-viruses.html?searchResultPosition=42>,
Dr. Enard and his colleagues have searched the human genome for these patterns
of genetic variation in order to reconstruct the history of an array of
viruses. When the pandemic struck, he wondered whether ancient coronaviruses
had left a distinctive mark of their own.
He and his colleagues compared the DNA of thousands of people across 26
different populations around the world, looking at a combination of genes known
to be
crucial<https://www.nytimes.com/2020/03/17/science/coronavirus-treatment.html>
for coronaviruses but not other kinds of pathogens. In East Asian populations,
the scientists found that 42 of these genes had a dominant version. That was a
strong signal that people in East Asia had adapted to an ancient coronavirus.
But whatever happened in East Asia seemed to have been limited to that region.
“When we compared them to populations around the world, we couldn’t find the
signal,” said Yassine Souilmi, a postdoctoral researcher at the University of
Adelaide in Australia and a co-author of the new study.
The scientists then tried to estimate how long ago East Asians had adapted to a
coronavirus. They took advantage of the fact that once a dominant version of a
gene starts being passed down through the generations, it can gain harmless
random mutations. As more time passes, more of those mutations accumulate.
Dr. Enard and his colleagues found that the 42 genes all had about the same
number of mutations. That meant that they had all rapidly evolved at about the
same time. “This is a signal we should absolutely not expect by chance,” Dr.
Enard said.
They estimated that all of those genes evolved their antiviral mutations
sometime between 20,000 and 25,000 years ago, most likely over the course of a
few centuries. It’s a surprising finding, since East Asians at the time were
not living in dense communities but instead formed small bands of
hunter-gatherers.
ADVERTISEMENT
Continue reading the main
story<https://www.nytimes.com/2021/06/24/science/ancient-coronavirus-epidemic.html?action=click&algo=bandit-all-surfaces&block=trending_recirc&fellback=false&imp_id=812686856&impression_id=30fa870e-d535-11eb-a15d-6dd6396f9409&index=2&pgtype=Article&pool=pool%2F91fcf81c-4fb0-49ff-bd57-a24647c85ea1®ion=footer&req_id=935318571&surface=most-popular-story&variant=0_bandit-all-surfaces#after-story-ad-3>
Aida Andres, an evolutionary geneticist at the University College London who
was not involved in the new study, said she found the work compelling. “I’m
quite convinced there’s something there,” she said.
Still, she didn’t think it was possible yet to make a firm estimate of how long
ago the ancient epidemic took place. “The timing is a complicated thing,” she
said. “Whether that happened a few thousand years before or after — I
personally think it’s something that we cannot be as confident of.”
Scientists looking for drugs to fight the new coronavirus might want to
scrutinize the 42 genes that evolved in response to the ancient epidemic, Dr.
Souilmi said. “It’s actually pointing us to molecular knobs to adjust the
immune response to the virus,” he said.
Dr. Anders agreed, saying that the genes identified in the new study should get
special attention as targets for drugs. “You know that they’re important,” she
said. “That’s the nice thing about evolution.”
