[yters]

does gain of function require directly engineering the sequence? i saw one gain of function expeeiment where a cat virus was exposed to mouse material, and underwent zoonosis on its own additionally the sequence can just be manually copied over that paper for some reason ignores plausible alternative approaches to creating viruses in the lab

[DiogenesKynikos]

Are you suggesting serial passage in the lab?

The problem with that theory is that the virus contains thousands of mutations throughout its genome, which would take decades of evolution to accumulate. In the wild, this virus jumps to a new host every few days, meaning that decades of evolution amount to thousands of generations of virus. No lab has the time to pass virus through so many animals.

[yters]

i dont understand why it would have to jump through a bunch of animals first. cant it go from bat to human?

fauci was conducting coronavirus gain of function experiments in wuhan in 2019 trying to go from bat to human, so at least some scientists didn't consider the evolutionary distance to be so great

UPDATE: newsweek article on fauci https://www.newsweek.com/dr-fauci-backed-controversial-wuhan...

[trhway]

>cant it go from bat to human?

That is the answer you get from the experiments, if it jumps then it can, if it doesn't jump, keep trying different strains and generations selectively bred in mice/ferrets/etc. (in addition to using human cells in vitro to filter the candidates at various stages, an interesting modern possibility is to use mice seeded with human cells with the receptors of target type like ACE2 in this case and/or with human cells from respiratory surfaces). In general it is like you'd selectively breed new type of apple or grain, condensing the decades of chaotic natural selection into managed selection over few years or even months when it comes to fast iterating objects like for example viruses and bacteria.

So far it looks like the experiments did succeed. China is a country where prison inmates voluntarily donate organs while still alive, and in general it sounds like their prisons are very harsh, comparable or even worse than for example in Russia. Compare to that getting infected with a flu and spending few weeks in a nice lab hospital being well fed and relieved from the hard labor and abuse by the guards and other prisoners - i suspect there would be a line to sign up for those experiments.

[DiogenesKynikos]

I can't make heads or tails of what you're saying. Fauci was conducting experiments in Wuhan? Where are you getting this from?

[yters]

here is the article about fauci endorsing and funding such research

https://www.newsweek.com/dr-fauci-backed-controversial-wuhan...

[DiogenesKynikos]

Good. This is very important reasearch, as the pandemic has shown.

[yters]

So I'm still not following. You say it is infeasible for a lab to generate sars2, yet it seems Fauci thinks it is feasible enough to fund an attempt.

If I understand your argument, you claim sars2 is too genetically different from the closest public sequences to have been lab engineered. But, what precludes a lab from discovering a virus in the wild that is close to making the jump, and then pushing it the rest of the way? I am not understanding the argument that we have to limit the range of possibility to only the publicly disclosed virus sequences.

For example, if you line up the ace2 site between sars2 and sars, they have a lot of similarity. This author claims the section is essentially copied over, although I don't know if it is statistically significant enough to not just be an accident. https://nerdhaspower.weebly.com/blog/scientific-evidence-and...

So, a "lab origin" theorist could say they isolated a virus in the wild, and copied over the ace2 section from sars, and then ran it through human tissue until it gain enough function to spread effectively in the human population. Is that less or more likely than a coronavirus in the wild mutating enough to make such a lethal jump to humans? Is there any way to put a probability on the two theories?