4 ms·

Or worse. If it is so easy to activate, there must be an evolutionary reason why we don’t have it.

MarkusQ 8mo ago
Systemic cost. We could have paper shredders, blenders, toasters, water taps, and so on that just ran all the time, but our utility bills would be ginormous. Same thing for our bodies.
- lokar 8mo ago
  Or the risk of autoimmune disease?
  - ekianjo 8mo ago
    Yes that's the obvious one
  - MarkusQ 8mo ago
    Yep. And probably increased allergies. Possibly decreased fertility. And who knows what else.
Rexxar 8mo ago
Maybe it would made the immune system age faster if it is "used" too much.
- ekianjo 8mo ago
  Inflammation is certainly not "free". It causes systemic damage.
  - tensor 8mo ago
    So does getting infected over and over. Much worse damage. Evolution isn't some magic thing that gives you the most optimal creature for a given metric. The only metric is procreation. Not longevity. Not a pleasant life.
gcanyon 8mo ago
I think you have evolution backwards. There only needs to not be a reason we need it to survive long enough to reproduce. Or more probabilistically, there needs to not be a significant reproductive benefit to it. And bear in mind that most people don't have a problem surviving colds and the like long enough to reproduce even with no vaccines at all, and that was probably more true for much of our evolutionary history when we were living much more isolated lives, and not cohabiting with chickens and pigs.
- ivan_gammel 8mo ago
  >There only needs to not be a reason we need it to survive long enough to reproduce. Humans had life expectancy even shorter than our fertility period until recently and they developed as social species hundreds of thousands years ago, for which living beyond fertility period is beneficial (grandparents were invented by evolution too). > And bear in mind that most people don't have a problem surviving colds That’s modern people with access to antibiotics etc. > that was probably more true for much of our evolutionary history when we were living much more isolated lives, and not cohabiting with chickens and pigs For much of our evolutionary history people were eating animals, getting viruses with them.
  - ipaddr 8mo ago
    If you made it to fertility age your life expectancy was much longer.
    - ivan_gammel 8mo ago
      Yes, and to get there we use immunity that is activated on demand. Clearly that was better from evolutionary perspective than preactivation or always-on.
      - jmye 8mo ago
        > Yes, and to get there we use immunity that is activated on demand. Clearly that was better from evolutionary perspective than preactivation or always-on. I don't think you understand evolution. Neither needs to be "better" for anything other than survival to reproduction. Evolution isn't min-maxing in a video game.
tshaddox 8mo ago
There doesn’t need to be an evolutionary reason why we don’t have something. That’s the default!
- ivan_gammel 8mo ago
  If something clearly helps survival and not an improbable thing to develop, the chances are high we would already have it. But we don’t and most species don’t. It is not the default, there likely exists a reason why.
  - Larrikin 8mo ago
    What's the reason
  - tshaddox 7mo ago
    > If something clearly helps survival and not an improbable thing to develop, the chances are high we would already have it. Well sure, but "not an improbable thing to develop" is doing a lot of work there. Again, everything complex is "improbable to develop," in the sense that evolution takes a lot of time and is very path dependent.
ajuc 8mo ago
Might be as simple as cost/effect in resource-constrained environment. Inflamation uses up resources. When we were hunter-gatherers and had to survive ice ages - it wasn't a good idea to waste calories and vitamins just in case. Better for 3 people out of 30 to die of flu than for all 30 to starve. Nowadays the optimal trade-off might be completely different.

Systemic cost. We could have paper shredders, blenders, toasters, water taps, and so on that just ran all the time, but our utility bills would be ginormous. Same thing for our bodies.

lokar 8mo ago
Or the risk of autoimmune disease?
- ekianjo 8mo ago
  Yes that's the obvious one
- MarkusQ 8mo ago
  Yep. And probably increased allergies. Possibly decreased fertility. And who knows what else.

Rexxar 8mo ago

Maybe it would made the immune system age faster if it is "used" too much.

ekianjo 8mo ago
Inflammation is certainly not "free". It causes systemic damage.
- tensor 8mo ago
  So does getting infected over and over. Much worse damage. Evolution isn't some magic thing that gives you the most optimal creature for a given metric. The only metric is procreation. Not longevity. Not a pleasant life.

gcanyon 8mo ago

I think you have evolution backwards. There only needs to not be a reason we need it to survive long enough to reproduce. Or more probabilistically, there needs to not be a significant reproductive benefit to it. And bear in mind that most people don't have a problem surviving colds and the like long enough to reproduce even with no vaccines at all, and that was probably more true for much of our evolutionary history when we were living much more isolated lives, and not cohabiting with chickens and pigs.

ivan_gammel 8mo ago
>There only needs to not be a reason we need it to survive long enough to reproduce. Humans had life expectancy even shorter than our fertility period until recently and they developed as social species hundreds of thousands years ago, for which living beyond fertility period is beneficial (grandparents were invented by evolution too). > And bear in mind that most people don't have a problem surviving colds That’s modern people with access to antibiotics etc. > that was probably more true for much of our evolutionary history when we were living much more isolated lives, and not cohabiting with chickens and pigs For much of our evolutionary history people were eating animals, getting viruses with them.
- ipaddr 8mo ago
  If you made it to fertility age your life expectancy was much longer.
  - ivan_gammel 8mo ago
    Yes, and to get there we use immunity that is activated on demand. Clearly that was better from evolutionary perspective than preactivation or always-on.
    - jmye 8mo ago
      > Yes, and to get there we use immunity that is activated on demand. Clearly that was better from evolutionary perspective than preactivation or always-on. I don't think you understand evolution. Neither needs to be "better" for anything other than survival to reproduction. Evolution isn't min-maxing in a video game.

tshaddox 8mo ago

There doesn’t need to be an evolutionary reason why we don’t have something. That’s the default!

ivan_gammel 8mo ago
If something clearly helps survival and not an improbable thing to develop, the chances are high we would already have it. But we don’t and most species don’t. It is not the default, there likely exists a reason why.
- Larrikin 8mo ago
  What's the reason
- tshaddox 7mo ago
  > If something clearly helps survival and not an improbable thing to develop, the chances are high we would already have it. Well sure, but "not an improbable thing to develop" is doing a lot of work there. Again, everything complex is "improbable to develop," in the sense that evolution takes a lot of time and is very path dependent.

ajuc 8mo ago

Might be as simple as cost/effect in resource-constrained environment. Inflamation uses up resources. When we were hunter-gatherers and had to survive ice ages - it wasn't a good idea to waste calories and vitamins just in case. Better for 3 people out of 30 to die of flu than for all 30 to starve. Nowadays the optimal trade-off might be completely different.