4 ms·

> long lifespan ...isn't it just better healthcare and nutrition?

gumby 3y ago
No, that increases the survival rate, but it's been documented for thousands of years at least that the "natural" human lifespan is over 70. Mean lifespan has been dragged down mainly because of high rates of infant mortality and, as you allude to, various untreatable diseases. But as we make progress on those, the mean has been shifting up.
Retric 3y ago
2,000 years significantly fewer people reached 90+ as a percentage of the population, but it still happened. We have done quite a lot in terms of infant mortality, but relatively little to extend the maximum age people reach. Take 1,000 random people born 100 BC vs 1,000 people born in 1900 and the oldest person from 1900 will very likely have lived longer but probably less than 10 years longer.
rbanffy 3y ago
Living longer can be advantageous as you can take care of your children and grandchildren for longer, as well as continue to amass resources after the reproductive age, but indirectly improving the chances of your descendants.
- Traubenfuchs 3y ago
  Like the gay uncle hypothesis. (-;
  - deleted 3y ago
    [deleted]
- InSteady 3y ago
  It's easy to forget in modern society, but in tribal society the elders were fountains of wisdom. When computers, reference materials, technical documents, libraries, school systems, etc don't exist, the value of lived experience goes through the roof. Being able to consult the elders when the group faces perplexing problems (who may have lived through something similar, or at least heard stories from the recently deceased generations who have) might mean the difference between between 20% of the population starving and no one starving.
- robwwilliams 3y ago
  This is all true but these indirect effects are generally too weak to actually modify allele frequencies in humans. These so-called grandmother effects were probably more forceful in the hunter-gatherer phase of human evolution—but even then may have been weak.
robwwilliams 3y ago
Yes!

No, that increases the survival rate, but it's been documented for thousands of years at least that the "natural" human lifespan is over 70. Mean lifespan has been dragged down mainly because of high rates of infant mortality and, as you allude to, various untreatable diseases. But as we make progress on those, the mean has been shifting up.

Retric 3y ago

2,000 years significantly fewer people reached 90+ as a percentage of the population, but it still happened. We have done quite a lot in terms of infant mortality, but relatively little to extend the maximum age people reach. Take 1,000 random people born 100 BC vs 1,000 people born in 1900 and the oldest person from 1900 will very likely have lived longer but probably less than 10 years longer.

rbanffy 3y ago

Living longer can be advantageous as you can take care of your children and grandchildren for longer, as well as continue to amass resources after the reproductive age, but indirectly improving the chances of your descendants.

Traubenfuchs 3y ago
Like the gay uncle hypothesis. (-;
- deleted 3y ago
  [deleted]
InSteady 3y ago
It's easy to forget in modern society, but in tribal society the elders were fountains of wisdom. When computers, reference materials, technical documents, libraries, school systems, etc don't exist, the value of lived experience goes through the roof. Being able to consult the elders when the group faces perplexing problems (who may have lived through something similar, or at least heard stories from the recently deceased generations who have) might mean the difference between between 20% of the population starving and no one starving.
robwwilliams 3y ago
This is all true but these indirect effects are generally too weak to actually modify allele frequencies in humans. These so-called grandmother effects were probably more forceful in the hunter-gatherer phase of human evolution—but even then may have been weak.

robwwilliams 3y ago

Yes!