“That alone should give people pause,” Dr. Rasmussen said of the team’s connection to Mr. Bannon’s nonprofit.
Dr. Yan and her colleagues did not respond to a request for comment.
Their original paper — known as “the Yan report” — was also seized upon by thousands online and reported on in The New York Post, even though experts rapidly debunked its findings. Researchers called it unscientific and said it ignored the wealth of data pointing to the virus’s natural origins.
Close relatives of the new coronavirus exist in bats. The virus may have moved directly into people from bats, or first jumped into another animal, such as a pangolin, before transitioning into humans. Both scenarios have played out before with other pathogens.
“We have a very good picture of how a virus of this kind could circulate and spill over into human beings,” said Brandon Ogbunu, a disease ecologist at Yale University.
It may take quite some time to pinpoint exactly which animals harbored the virus along this chain of transmission, if scientists ever do at all — inevitably leaving some parts of the virus’s origin story ambiguous. Like many other conspiracy theories, the lab-made hypothesis “exploits the open questions in an ongoing investigation,” Dr. Ogbunu said.
But there is no evidence so far to support a synthetic source for the virus.
Dr. Yan’s Twitter account was suspended in September 2020 for pushing coronavirus disinformation. She shared the “second Yan report” from a second Twitter account, which has gained more than 34,000 followers.
Together, the papers written by Dr. Yan and her colleagues lay out what they identified as abnormalities in the genome sequence of the coronavirus. They suggested that those unusual features indicated that the virus’s genome had been purposefully spliced together and modified, using the genetic material from other viruses — a sort of Frankenstein’s monster pathogen, Dr. Yan told Fox News in September. The cousins of the coronavirus that had been identified in bats, they said, were also fake, human-made constructions, thus supposedly quashing the natural origin hypothesis.