One of the studies — neither of which has been peer-reviewed or published in a professional journal — used spatial analysis to show that the earliest known COVID-19 cases, diagnosed in December 2019, were centered on the market.
The other study says the two major viral lineages were the result of at least two events in which the virus crossed species into humans.
Experts have roundly condemned the theory of a laboratory origin for the virus, saying that there’s no proof of such origins or of a leak.
The new studies take this area of research “to a new level” and are the strongest evidence yet that the pandemic had animal-related origins, Michael Worobey, a professor and head of ecology and evolutionary biology at the University of Arizona told CNN.
Garry was co-author on the study that found at least two zoonotic or animal-transmission events.
Worobey also said human surveillance is crucial to preventing future pandemics, adding that experts and officials should be better at detecting cases of respiratory disease with no clear cause, isolating patients and sequencing viruses.