Thread by @AlabasterDiadem

For example, SARS-CoV-2’s genome closely resembles that of a bat coronavirus, but a small section of the
genome called the “polybasic cleavage site,” believed to provide a selective advantage for disease transmission, would have been expected to evolve over time but instead

is present in the earliest sequences of the virus. Investigators can further determine whether the infecting agent’s genome so closely resembles a given reference
strain that a period of limited or no replication is likely. Such socalled “frozen evolution,” when an infecting

agent’s genome lacks the expected accumulation of mutations over time, suggests that alternate origin hypotheses such as a laboratory accident must be explored.

one problem with what they said: "the ensuing spread follows expected epidemiological characteristics of a
natural event."

No it doesn't. @Ayjchan's paper that you cite later already mentioned that it was well-adapted from the get-go. if it were a natural zoonotic event, ace2

binding would get progressively better, not remain high as always. the spike appears to not be mutating much at all. and also, there's so little about the other genetic weirdness, like the reference bat virus genome they mention.