My guess would have been 5% or less, but I don't know anything about it other than from a few rumors so I am not very confident. We have seen plenty of previous pandemics that presumably did not require any human intervention to get started, but now thousands—even millions—of people have access to biotech tools and information. The Washington Post says it's doubtful that the virus came from a lab, but the evidence provided suggests that we don't know where it originated. The expressed concern about terrorists and weirdos made me exclude well-intentioned researchers who accidentally release a virus, but that's just what Rees meant by "bioerror." Pinker seems to have accepted this bet without a definition of that term.
The early samples have reportedly been destroyed. It would be trivial to determine if the virus originated from the lab if the effort was made. Shi was doing gain-of-function experiments with SARS-Cov in a lab without sufficient safeguards, and epidemiological data shows it did not originate at the wet market, but nearby. I don't think it is fully appreciated what types of experiments Shi and others were conducting. They were taking coronaviruses, and making them infect human cells efficiently, both by driving random mutations, and by engineering them to do so.In March, Shi told the Scientific American that in the early days of the outbreak, even she wondered whether coronaviruses were to blame. “Could they have come from our lab?” After all, her lab had collected and sequenced tens of thousands of coronaviruses over the past decade. (She has since adamantly denied that the new coronavirus could have emerged from her lab. Her boss and the WIV issued similar denials.)
The Scientific American article is pretty amazing. The description of Shitou Cave is just as creepy as Kitum Cave was in The Hot Zone. "Editor’s Note (4/24/20): This article was originally published online on March 11. It has been updated for inclusion in the June 2020 issue of Scientific American and to address rumors that SARS-CoV-2 emerged from Shi Zhengli’s lab in China." There are many differences between the March 11 article and the current version, mostly editorial.
Interesting. After:The genomic sequences of the viral strains from patients are, in fact, very similar to one another, with no significant changes since late last December, based on analyses of 326 published viral sequences. “This suggests the viruses share a common ancestor,” Baric says.
Since then, researchers have published more than 4,500 genomic sequences of the virus, showing that samples around the world appear to “share a common ancestor,” Baric says.