Dr. Relman of Stanford organized the letter to Science with other prominent colleagues, including Alina Chan, a scientific adviser at the Broad Institute in Cambridge, Mass., and Jesse Bloom, a virologist at the Fred Hutchinson Cancer Center in Seattle.
In August, Mr. Metzl helped plan a private bipartisan briefing for senators about the lab leak hypothesis, where Dr. Relman and Dr. Bloom spoke.
“I left the meeting with a much more open mind,” said Senator Richard Blumenthal, Democrat of Connecticut.
Market Clues
As backers of the lab leak idea made their case in Congress, Michael Worobey, an evolutionary biologist at the University of Arizona, set out to test those claims. Having once investigated — and helped to discredit — a theory that AIDS came from contaminated polio vaccines, he believed a lab leak was possible and so he signed the Science letter.
He first nudged the scientific journal Nature, he said, to request that researchers from the Wuhan Institute of Virology make available genetic sequences of previous coronaviruses they had reported in the journal. They did, and shortly thereafter, in May 2021, posted a study describing those viruses, none of which was closely enough related to the pandemic virus that genetic tinkering could have produced it.
Next, Dr. Worobey analyzed the earliest known Covid patients, finding that a disproportionate number had worked at or visited the market.
Meanwhile, evidence emerged that live mammals known to spread coronaviruses — including raccoon dogs — were being sold at the Huanan market before the pandemic. And in September 2021, a report of coronaviruses recently discovered in Laotian bats showed that naturally occurring viruses were capable of latching onto human cells.