  There is a near consensus view that SARS-CoV-2 has a natural zoonotic origin;
however, several characteristics of SARS-CoV-2 taken together are not easily
explained by a natural zoonotic origin hypothesis. These include: a low rate of
evolution in the early phase of transmission; the lack of evidence of
recombination events; a high pre-existing binding to human ACE2; a novel furin
cleavage site insert; a flat glycan binding domain of the spike protein which
conflicts with host evasion survival patterns exhibited by other coronaviruses,
and high human and mouse peptide mimicry. Initial assumptions against a
laboratory origin, by contrast, have remained unsubstantiated. Furthermore,
over a year after the initial outbreak in Wuhan, there is still no clear
evidence of zoonotic transfer from a bat or intermediate species. Given the
immense social and economic impact of this pandemic, identifying the true
origin of SARS-CoV-2 is fundamental to preventing future outbreaks. The search
for SARS-CoV-2's origin should include an open and unbiased inquiry into a
possible laboratory origin.
