[sampo]

One way to increase the virulence of a virus in lab, is to let it infect cells in cell culture, and replicate for a large number of generations. This is sort of natural evolution, guided in a lab, and doesn't involve genetic modification.

[angelzen]

We'll never know for sure. Which is too bad, because the plan of "Let's comb remote caves for hundreds of dangerous pathogens, bring them to a lab in the middle of a 10M metropolis, then perform gain-of-function research on them" is as nutty as it sounds.

[noahtallen]

I don’t know if it’s that nutty! “Let’s study the most dangerous pathogens” sounds like a good idea to me. So the nutty part would be doing it in a city, but would that actually make a huge difference compared to a remote lab? If it got out of a remote lab, one can imagine it would ultimately end up spreading quite far exponentially, even if it would take slightly longer to reach a metropolis.

Seems to me the main thing would be ensuring foolproof protection from anything escaping at the lab — which obviously was lacking if the theory is true. So the idea seems fine to me.

[bradknowles]

If you think anything can be made foolproof, then all I can say is that you must not yet have met a sufficiently foolish fool.

The one and only job that any fool has is to defeat any so-called “foolproof” system that they come into contact with. And, taken as a whole, history has proven that they are unbeatable.

[Metacelsus]

Typically serial passage decreases the virulence (since there's no selection pressure from the immune system, mutations accumulate in immune evasion genes). But if it's an animal virus, this is a good way to evolve it to infect human cells.