Your claim that such a pathogen is very likely impossible seems oddly strong to me, given that evolutionary constraints are not the same thing as physical constraints.
I think this is an important point (as are the rest of your points), and something similar came to my mind too. I think we may be able to put it more strongly. Your phrasing makes me think of evolution ātryingā to create the sort of pathogen that could lead to human extinction, but there being constraints on its ability to do so, which, given that they arenāt physical constraints, could perhaps be overcome through active technological effort. It seems to me that evolution isnāt even ātryingā to create that sort of pathogen in the first place.
In fact, Iāve seen it argued that natural selection actively pushes against extreme virulence. From the Wikipedia article on optimal virulence:
A pathogen that is too restrained will lose out in competition to a more aggressive strain that diverts more host resources to its own reproduction. However, the host, being the parasiteās resource and habitat in a way, suffers from this higher virulence. This might induce faster host death, and act against the parasiteās fitness by reducing probability to encounter another host (killing the host too fast to allow for transmission). Thus, there is a natural force providing pressure on the parasite to āself-limitā virulence. The idea is, then, that there exists an equilibrium point of virulence, where parasiteās fitness is highest. Any movement on the virulence axis, towards higher or lower virulence, will result in lower fitness for the parasite, and thus will be selected against.
I donāt have any background in this area, so Iām not sure how well that Wikipedia article represents expert consensus, what implications to draw from that idea, and whether thatās exactly what you were already saying. But it seems to me that this presents additional reason to doubt how much we can extrapolate from what pathogens naturally arise to what pathogens are physically possible.
(Though I imagine that what pathogens are physically possible still provides some evidence, and that itās reasonable to tentatively raise it in discussions of risks from engineered pandemics.)
I think this is an important point (as are the rest of your points), and something similar came to my mind too. I think we may be able to put it more strongly. Your phrasing makes me think of evolution ātryingā to create the sort of pathogen that could lead to human extinction, but there being constraints on its ability to do so, which, given that they arenāt physical constraints, could perhaps be overcome through active technological effort. It seems to me that evolution isnāt even ātryingā to create that sort of pathogen in the first place.
In fact, Iāve seen it argued that natural selection actively pushes against extreme virulence. From the Wikipedia article on optimal virulence:
I donāt have any background in this area, so Iām not sure how well that Wikipedia article represents expert consensus, what implications to draw from that idea, and whether thatās exactly what you were already saying. But it seems to me that this presents additional reason to doubt how much we can extrapolate from what pathogens naturally arise to what pathogens are physically possible.
(Though I imagine that what pathogens are physically possible still provides some evidence, and that itās reasonable to tentatively raise it in discussions of risks from engineered pandemics.)