[jmccorm]

Apart from more people falling sick (as bad as that is), is there a more fundamental concern that if it runs wild in a less developed country, it'll mutate into something more dangerous? As infections climb, the coronavirus (based on less stable RNA) gets more chances to mutate into something even more virulent or deadly?

[rwmj]

Flu viruses get less dangerous over time. The more deadly strains literally kill off their hosts, making those strains less likely to spread.

[jmccorm]

Is that a universal truth, or is it historical? Situational? This virus is said to spread well before a person even knows they're infected. A mutation could simply extend that period. Or it could increase the degree to which it is contagious without affecting mortality, right? Or are you saying that this simply doesn't happen in the real world? Flu viruses only mutate with regards to lethality, and only in a way that works against its overall impact?

[bra4you]

"Is that a universal truth, or is it historical? Situational?"

It it experience based on historical data. A virus jumping to a new host (species) will be more aggressive in the beginning until it has adopted (mutated) to his new host.

While this is not a universal truth, it is experience and could also be backed up mathematically (>host dies to soon, virus can not spread) and by game theory.