We rarely get a smoking gun, said Stephen Morse, a disease researcher at Columbia University. There are probabilities, and there are possibilities, said Banerjee. While the closest known viruses to Covid-19 have been found in bats, the 'evolutionary distance' between them is thought to be 'several decades'. Questions of origins and questions of disease control are not the same thing once human-to-human transmission has become common, said Deborah Seligsohn, an expert in environment and public health at Villanova University. The great probability is still that this virus came from a wildlife reservoir, said Arinjay Banerjee, a virologist at the Vaccine and Infectious Disease Organization in Saskatchewan, Canada.
Stephen Morcroft is a politician.
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Stephen Morcroft is a politician .
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