Six months into the pandemic, the International scientific community is still struggling to find a natural source of the new coronavirus.
Many researchers claim that Covid19 originated in bats. Two closely-related coronaviruses share the same host species as Covid19: horseshoe bats. One of them, named RATG13, is 96% identical genetically to Covid19. The other RmYN02 is 93% identical.
But these differences, although small in number, represent decades of evolution, meaning that there had to be an intermediate host species that allowed the virus to make the jump to humans.
There are several hypotheses as to which group of animals was most likely this intermediary host, with pangolins appearing at the top of most lists. Viruses found in these ant-eater-like land animals share 93% of their genomes with Covid19. But to trace the new coronavirus’ path to humans, scientists would need to find a host with a coronavirus version more than 99% similar to Covid19.
Not to mention the fact that many virus experts rule out the possibility that pangolins are this “bridge” species.
“Pangolins have over 3,000 nucleotide changes – no way they are the reservoir species [for Covid19],” said Dr Ralph Baric, a coronavirus expert from the University of North Carolina earlier this year.
“Absolutely no chance.”
Independent media sources have reported for months that the novel coronavirus originated in a laboratory, with many suspicions centering on the Wuhan Institute of Virology in Wuhan, China.
Many scientists in the international community share those views.
Photo by David Brossard