[prestonh]

I don't think there's much direct evidence to support natural spillover event other than that much of the initial spread could be localized to a wet market, which may have had vendors selling meat from animals known to carry these types of viruses. That seems like pretty weak evidence, though. Other than that, IMO we should have very high prior weight assigned to the natural origin hypothesis in the Bayesian sense, so even without new direct evidence it's still reasonable to believe that hypothesis to be more likely.

[jacquesm]

About 60% of all diseases is the result of spillover, and that's only the part that we can trace. The null hypothesis is that this was a spillover, anything else requires hard evidence, not the other way around. There are numerous recent cases of documented spillover, but there isn't a single documented case of a lab leak leading to a major outbreak.

The people that keep pushing that angle are usually not in this for the science but to stoke the fire.

[zpeti]

Why does either option not require hard evidence? I don’t understand your distinction. Something that happens 60% of the time is almost a hard guarantee that’s that what happened now? Really?

You also ignore all circumstantial human behaviour around this, like China being completely unwilling to cooperate in any way in the investigation. Why? Surely if it was definitely a spillover they would cooperate because it’s not exactly their fault?

[jacquesm]

That is a gross misreading of what I wrote. 60% is the pathogens for which we can even after a very long time trace their origin to a spillover, but the numbers are far higher than that, we just don't have the proof.

Hard evidence is required for exceptional cases, especially when culpability is involved. Whereas the 'natural' way may simply not have left enough evidence at all to be able to trace it.