Corona Virus Apparently Already in East Asia 20,000 Years Ago, This is Scientists’ Explanation

New York, Beritasatu.com – Researchers have found evidence that the epidemic virus corona once swept through East Asia some 20,000 years ago, and left an evolutionary imprint on the DNA of people living today.

New study shows virus corona An ancient plague plagued the region for years, the researchers said. These findings could have dire implications for the pandemic Covid-19 if not immediately controlled through vaccination.

“This (finding) should worry us,” said David Enard, an evolutionary biologist at the University of Arizona who led the study, which was published Thursday in the journal Current Biology. “What is happening today will probably last from generation to generation.”

So far, researchers have been unable to look back too far into the history of this family of pathogens. Over the past 20 years, three viruses corona have adapted to infect humans and cause severe respiratory diseases: Covid-19, SARS, and MERS. Studies on each of these viruses show they jumped to our species from bats or other mammals.

Four viruses corona others can also infect humans, but usually only cause mild colds. Scientists don’t directly observe the virus corona these become human pathogens, so they rely on indirect clues to predict when the jump occurred.

Virus corona acquire new mutations at a regular rate, so comparing their genetic variation makes it possible to determine when they diverged from their ancestors.

The newest of the mild corona virus is called HCoV-HKU1, crossed the species barrier in the 1950s. The eldest, called HCoV-NL63, probably 820 years old.

But before that point, traces of the virus corona cold, until Enard and his colleagues apply a new method to the search. Instead of looking at genes corona virus, the researchers looked at their effect on the DNA of their human hosts.

Over several generations, viruses drive a large number of changes in the human genome. A mutation that protects against viral infection may mean the difference between life and death, and it will be passed on to the offspring. Life-saving mutations, for example, allow people to bypass viral proteins.

But viruses can also evolve. Their proteins can change shape to overcome the host’s defenses. And those changes may spur the host to develop even more counterattacks, leading to more mutations.

When a new mutation randomly occurs to confer resistance to a virus, it can quickly become more common from one generation to the next. And other versions of the gene, in turn, are becoming rarer. So if one version of a gene dominates all other versions in a large group of people, scientists know it’s most likely a sign of rapid evolution in the past.

In recent years, Enard and his colleagues have searched the human genome for these patterns of genetic variation in order to reconstruct the history of a series of viruses. When the pandemic hit, he wondered if the virus corona the ancients have left their own distinctive mark.

He and his colleagues compared the DNA of thousands of people in 26 different populations around the world, looking at combinations of genes known to be essential for viruses corona but not other types of pathogens. In East Asian populations, scientists found that there were 42 genes that had dominant versions. It is a strong signal that people in East Asia have adapted to the virus corona ancient.

But whatever happens in East Asia seems to be confined to that region. “When we compared it with populations around the world, we couldn’t find a signal,” said Yassine Souilmi, researcher postdoctoral at the University of Adelaide in Australia and co-author of the new study.

The scientists then tried to estimate how long East Asians had adapted to the virus corona. They benefit from the fact that once the dominant version of a gene begins to be passed down from generation to generation, it can acquire harmless random mutations. The more time passed, the more mutations accumulated.

Enard and his colleagues found. the 42 genes all have nearly the same number of mutations. That meant that they all evolved rapidly at about the same time. “This is a signal we shouldn’t expect by chance,” Enard said.

They estimate that all of these genes developed their antiviral mutations between 20,000 and 25,000 years ago, most likely over several centuries. This was a surprising finding, as East Asians at that time did not live in dense communities, but instead formed small hunter-gatherer groups.

Aida Andres, an evolutionary geneticist at University College London who was not involved in the new study, said she found the research interesting. “I’m pretty sure there’s something there,” he said.

Still, he hadn’t thought of making a definite estimate of how long the ancient epidemic would last. “Time is a complicated thing,” he said. “Whether it happened a few thousand years before or after, I personally think it’s something we can’t be sure of.”

Scientists looking for a drug to fight the virus corona may want to examine these 42 genes that evolved in response to ancient epidemics, Souilmi said. “This actually leads us to the molecular knobs for adjusting the immune response to the virus,” he said.

Source: channelnewsasia.com

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