> the selection pressure that promotes this kind of evolution is _death._ Not necessarily. Assume that people try to self-quarantine as soon as they notice sy

> the selection pressure that promotes this kind of evolution is _death._ Not necessarily. Assume that people try to self-quarantine as soon as they notice symptoms. (They don't need to be 100% effective at this.) Consider "mutations that affect how quickly it spreads within your body". Those that increase said efficiency would presumably increase the likelihood of death; but they would also probably shorten the "asymptomatic spreading" period, which means they'd get selected against; this selection happens even among those that aren't dying. (Author background disclaimer: No biology beyond 9th grade.)