5 ms·

In the microbial world, the mildest strains will survive the longest. Ideally it would even become symbiotic to help fight antibiotic resistant bacteria.

whatshisface 7y ago
Switching from humans to human-infecting bacteria would be a very unlikely species jump.
moyix 7y ago
This is commonly repeated but not really true, see http://www.iayork.com/MysteryRays/2007/08/26/rabbits-1-virus-1-evolution-of-viral-virulence/ http://www.iayork.com/MysteryRays/2007/08/26/rabbits-1-virus...
samcal 7y ago
I'm not sure that your first sentence is true. The symptomatic effect that a not-mild virus strain has can help it spread, for obvious reasons. It seems like there's an optimization problem there, with a sweet spot where the virus doesn't kill its host, but makes them cough and sneeze to spread to other hosts.
- pingyong 7y ago
  I could imagine that not causing symptoms would probably be ideal if the virus could survive endlessly and not get eventually killed by our immune system. But anything that does get killed by our immune system is kind of on the clock and needs to spread relatively quickly.
ajross 7y ago
This is sort of true, in a Darwinian sense. But it's true because viruses which kill their hosts inhibit their own propagation! It doesn't help us at all if our goal is to prevent those people from being killed in the first place.
vikramkr 7y ago
I mean, it might not survive the longest if it's more infective, but evolution doesn't work like that, and we're worried about short term impacts. Yeah if it's really bad we'll eventually make it go extinct just like we made smallpox go extinct, but smallpox didn't adapt and survive and become less wild. We are the evolutionary pressure driving it to exinction - the virus right now is plenty happy surviving as the more virulent strain it is. It's survival of the good enough, not survival of the fittest, and a deadly strain is good enough to keep surviving.

whatshisface 7y ago

Switching from humans to human-infecting bacteria would be a very unlikely species jump.

moyix 7y ago

This is commonly repeated but not really true, see http://www.iayork.com/MysteryRays/2007/08/26/rabbits-1-virus-1-evolution-of-viral-virulence/ http://www.iayork.com/MysteryRays/2007/08/26/rabbits-1-virus...

samcal 7y ago

I'm not sure that your first sentence is true. The symptomatic effect that a not-mild virus strain has can help it spread, for obvious reasons. It seems like there's an optimization problem there, with a sweet spot where the virus doesn't kill its host, but makes them cough and sneeze to spread to other hosts.

pingyong 7y ago
I could imagine that not causing symptoms would probably be ideal if the virus could survive endlessly and not get eventually killed by our immune system. But anything that does get killed by our immune system is kind of on the clock and needs to spread relatively quickly.

ajross 7y ago

This is sort of true, in a Darwinian sense. But it's true because viruses which kill their hosts inhibit their own propagation! It doesn't help us at all if our goal is to prevent those people from being killed in the first place.

vikramkr 7y ago

I mean, it might not survive the longest if it's more infective, but evolution doesn't work like that, and we're worried about short term impacts. Yeah if it's really bad we'll eventually make it go extinct just like we made smallpox go extinct, but smallpox didn't adapt and survive and become less wild. We are the evolutionary pressure driving it to exinction - the virus right now is plenty happy surviving as the more virulent strain it is. It's survival of the good enough, not survival of the fittest, and a deadly strain is good enough to keep surviving.