You mean the polytomy argument? As I said earlier, it's incredibly weak. They're assuming they can capture the spread of the first human cases in an SIR-type model well enough to recreate the shape of that early phylogenetic tree. During this pandemic, such models haven't shown particularly good accuracy in forecasting case count at a country level, certainly no better than less physical curve-fitting approaches like Youyang Gu's. I see no reason to believe such a model would be accurate on the more difficult problem of SARS-CoV-2's early spread, in an unknown group of people with unknown behaviors, and perhaps different biology for those earliest variants too.
Essentially Pekar's argument is a "two introductions of the gaps"--that if their model of a single introduction doesn't conform to reality, then it must have been two introductions. But the other possibility is simply that their model is wrong. I see no reason to exclude that. Here are some Twitter threads expressing the same concerns in more detail:
Essentially Pekar's argument is a "two introductions of the gaps"--that if their model of a single introduction doesn't conform to reality, then it must have been two introductions. But the other possibility is simply that their model is wrong. I see no reason to exclude that. Here are some Twitter threads expressing the same concerns in more detail:
https://twitter.com/NimwegenLab/status/1563490916006264833
https://twitter.com/nizzaneela/status/1509431997713764352