In the past 20 years, the world has faced three epidemics caused by a coronavirus. The SARS-CoV outbreak in 2002, the MERS-CoV- outbreak in 2012, and finally the SARS-CoV-2 in late 2019 confirmed the potential of coronaviruses to cause serious illness in humans.
An ancient coronavirus caused an epidemic in East Asia 20,000 years ago, and its effect can be traced in genes.
A new study found that tens of thousands of years before the 21st century, the coronavirus was already wreaking havoc on the health of our species.
“In the same way that the rings of a tree reveal the conditions it experienced during its growth, the modern human genome contains information that allows us to trace tens of thousands of years of evolution”, explains Kirill Alexandrov, professor at the Center for Genomics and Health Custom from the Queensland University of Technology.
The researchers used data from the1000 Genomes Project(the world’s largest public catalog of genetic variations) looking for changes in human genes that encode proteins that interact with SARS-CoV-2.
The sample included genomes of more than 2,500 people from 26 different countries around the globe in search of the specific proteins produced by cells that interact with viruses when they parasitize them. The result showed that the viral proteins were present only in 5 specific countries of the 26 studied, all belonging to East Asia.
The interaction was proof that tens of thousands of years ago, a common group of human ancestors from East Asia faced an epidemic triggered by another coronavirus similar to COVID-19.
So 20,000 years ago, human groups in what is now Japan, China, Mongolia, North and South Korea, and Taiwan were victims of the oldest coronavirus disease on record. And although it is impossible to know how serious the epidemic was and how many fatalities it left at that time, the study published inCurrent Biologyfound evidence of genetic adaptation to the coronavirus family in 42 genes from current populations in these countries.
In these cases, “selection favored variants of human genes related to pathogenesis, with adaptive changes that presumably led to less severe disease,” according to Alexandrov.
The study also sets a precedent for analyzing epidemics of the remote past with increasingly sophisticated genetic analysis, a novel tool to prevent and avoid the emergence of new diseases with pandemic potential.