More than five years after the Covid-19 pandemic was declared, its origins remain a subject of intense – and often acrimonious – debate among scientists and the wider public. There are two broad, competing theories. The natural-origins hypotheses suggest the pandemic began when a close relative of Sars-CoV-2 jumped from a wild animal to a human through the wildlife trade. In contrast, proponents of lab-leak theories argue that the virus emerged when Chinese scientists became infected through research-associated activities.
A perplexing aspect of the controversy is that prominent scientists continue to publish studies in leading scientific journals that they say provide compelling evidence for the natural-origins hypotheses. Yet rather than resolving the issue, each new piece of evidence seems to widen the divide further.
