I think Toby’s use of “evenly split” is a bit of a stretch in 2024 with the information available, but lab leak is definitely still plausible. To quote Scott in the review:
Fourth, for the first time it made me see the coronavirus as one of God’s biggest and funniest jokes. Think about it. Either a zoonotic virus crossed over to humans fifteen miles from the biggest coronavirus laboratory in the Eastern Hemisphere. Or a lab leak virus first rose to public attention right near a raccoon-dog stall in a wet market. Either way is one of the century’s biggest coincidences, designed by some cosmic joker who wanted to keep the debate [...] acrimonious for years to come.
I think lab leak is now a minority position among people who looked into it, but it’s not exactly a fringe view. I would guess at least some US intelligence agencies still think lab leak is more likely than not, for example.
The former. I think it should be fairly intuitive if you think about the shape of the distribution you’re drawing from. Here’s the code, courtesy of Claude 3.5. [edit: deleted the quote block with the code because of aesthetics, link should still work].