Studying the genomes of modern humans from 26 worldwide populations, researchers discovered the genetic “footprint” of an ancient coronavirus outbreak. Studies like this one could help identify viruses that have caused epidemics in the distant past and may do so in the future.
A new study co-authored by a University of Arizona researcher has discovered a coronavirus epidemic broke out in the East Asia region more than 20,000 years ago, with traces of the outbreak evident in the genetic makeup of people from that area.
In a paper published in Current Biology, researchers analyzed the genomes of more than 2,500 modern humans from 26 worldwide populations, to better understand how humans have adapted to historical coronavirus outbreaks. The team, co-led by researchers at the University of Arizona and the University of Adelaide, used computational methods to uncover genetic traces of adaptation to coronaviruses, the family of viruses responsible for three major outbreaks in the last 20 years, including the ongoing pandemic.
In the past 20 years, there have been three outbreaks of epidemic severe coronaviruses: SARS-CoV leading to Severe Acute Respiratory Syndrome, which originated in China in 2002 and killed more than 800 people; MERS-CoV leading to Middle East Respiratory Syndrome, which killed more than 850 people; and leading to COVID-19, which has killed 3.8 million people.
But this study of the evolution of the human genome has revealed another large coronavirus epidemic broke out thousands of years earlier.
“It is like finding fossilized dinosaur footprints instead of finding fossilized bones directly,” said David Enard, a professor in the UArizona Department of Ecology and Evolutionary Biology and one of the study’s lead authors. “We did not find the ancient virus directly – instead we found signatures of the natural selection that it imposed on human genomes at the time of an ancient epidemic.”
The team synthesized both human and SARS-CoV-2 proteins, without using living cells, and showed that these interacted directly and specifically pointed to the conserved nature of the mechanism coronaviruses use to invade cells. Modern human genomes contain evolutionary information tracing back hundreds of thousands of years, including physiological and immunological adaptions that have enabled humans to survive new threats, including viruses.
The results revealed that the ancestors of East Asian people experienced an epidemic of a coronavirus-induced disease… Brinkwire News Summary.