Daily Star
There may have been an outbreak of coronavirus in East Asia some 25,000 years ago, a new study has claimed.
The epidemic may have even altered people’s DNA, resulting in permanent genetic adaptations that gave those living in that part of the world an advantage in fighting off a Covid-19 infection during the current pandemic.
David Enard, an evolutionary geneticist at the University of Arizona in Tucson, shared the findings at the virtual annual meeting of the American Association of Physical Anthropologists last week.
His research group used a publicly available DNA database of 2,504 individuals from 26 different ethnic populations across five continents, including Chinese Dai, Vietnamese Kinh and African Yoruba people.
Their analysis first focused on 420 proteins known to interact with coronaviruses, including 332 that interact with SARS-CoV-2, the virus which causes Covid-19. These interactions could range from boosting immune responses to making it easier for a virus to hijack a cell.
Substantially increased production of all 420 proteins, which is a sign of past exposures to coronavirus-like epidemics, was only present in the East Asians.
The group managed to trace the viral responses of 42 of those proteins back to approximately 25,000 years ago.
Analysis of the genes that orchestrate the production of said proteins determined specific variants became more common at that time but had levelled off in frequency by around 5,000 years ago.
Prof Enard said this pattern is consistent with an initially vigorous genetic response to a virus that then waned over time, either as East Asians adapted to it or as the virus lost its ability to cause disease.
Coronaviruses are a family of viruses that cause illness, of which seven different types have been identified in humans – including those responsible for the SARS, MERS and Covid-19 epidemics.
