How did we evolve to live up to elderly life?

[SitNHit]

Maybe a creator designed it that way, ooops, sry...

[Phil153]

I think all the evolutionary arguments for old age (tribes that had grandparents were fitter, etc) are nonsense.

The man reason we live to an old age because our bodies have enough vitality in youth to last for a number of years after our prime. No different to a car whose components generally work for a 10 year lifespan but is still going after 40.

[vhawk01]

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I think all the evolutionary arguments for old age (tribes that had grandparents were fitter, etc) are nonsense.

The man reason we live to an old age because our bodies have enough vitality in youth to last for a number of years after our prime. No different to a car whose components generally work for a 10 year lifespan but is still going after 40.

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But an important part of that would have to be that designing bodies with this extra vitality comes at no cost over designing less vital bodies. That may very well be true: the adaptations that were selected for in other niches and for other conflicts might just have, as a side effect, an increase in 'vitality.'

But its not exactly obvious that this is the case. It seems, perhaps superficially, that building a body that is capable of living 120 years takes more resources than building one that lasts 40 years, and these resources are wasteful, unless you can posit some benefit to grandparents. So, we've either got to explain how the resources required are identical or explain the benefit that offsets the costs. Madnak and others are trying to do the latter, and it seems like you are saying the former?

[chezlaw]

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I think all the evolutionary arguments for old age (tribes that had grandparents were fitter, etc) are nonsense.

The man reason we live to an old age because our bodies have enough vitality in youth to last for a number of years after our prime. No different to a car whose components generally work for a 10 year lifespan but is still going after 40.

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That might be true but only if there was no significant evolutionary advantage either way.

chez

[abridge]

Sharing wisdom, increasing general happiness of others, taking care of children all serve a purpose in society.

Depends on the grandparents, of course. Mine are late 60's/early 70's and still kickin' - and I'd say they produce a lot of benefit for the individuals that are around them.

Evolutionarily speaking, old people increase the ability for society to produce rational, thinking, and adaptable, well-rounded beings. Using the same perspective from the "technology as a 7th kingdom" guy, older people + technology both aid in creating a good environment for growth in this way.

[Phil153]

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I think all the evolutionary arguments for old age (tribes that had grandparents were fitter, etc) are nonsense.

The man reason we live to an old age because our bodies have enough vitality in youth to last for a number of years after our prime. No different to a car whose components generally work for a 10 year lifespan but is still going after 40.

[/ QUOTE ]

But an important part of that would have to be that designing bodies with this extra vitality comes at no cost over designing less vital bodies. That may very well be true: the adaptations that were selected for in other niches and for other conflicts might just have, as a side effect, an increase in 'vitality.'

But its not exactly obvious that this is the case. It seems, perhaps superficially, that building a body that is capable of living 120 years takes more resources than building one that lasts 40 years, and these resources are wasteful, unless you can posit some benefit to grandparents. So, we've either got to explain how the resources required are identical or explain the benefit that offsets the costs. Madnak and others are trying to do the latter, and it seems like you are saying the former?

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Vitality and spare energy in youth is a huge advantage in survival and sexual selection. Immune systems that are capable of warding off more disease in youth will no doubt enable a person to better avoid disease in older age. Heart muscles that can take prolonged strain in youth would no doubt outlast those that can't, all things being equal.

There's also the fact that the longer lifespans mean more opportunities for reproduction. Even men of Sklansky's age occasionally get one away in a healthy female of reproductive age. Perhaps female longevity is piggybacked on the genes that cause male longevity? Who knows

Besides, why would evolution design us to suddenly die when we're 40? It makes no sense. From what I've seen bodies carry on for as long as it can before they wear out.

I have no doubt that there are species of non or less social animals who would live past viable breeding age if kept stimulated.

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That might be true but only if there was no significant evolutionary advantage either way.

chez

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Many human traits are no doubt byproducts of other mechanisms. For example, our strong social bonds may well be a byproduct of some mutation that caused longer periods of infancy and weaker offspring. Or a grouping of traits causing more gray matter and longer brain development times. The cause of social behavior may not have been the direct advantages it provided to groups, but rather of byproduct of more effective rearing patterns, such as the development of bonding and communication systems between individual mothers and children, that allowed a greater development of intelligence and knowledge in those children. Just because we have some trait doesn't mean that that specific trait provided an evolutionary advantage.

In fact, this is one of my pet peeves when the people (including experts) talk about evolution. The authority you guys give to your evolutionary interpretations of human behavior is amazing, and on par with a lot of religious thought. You simply have no freaking clue how these things developed (and neither do I). You apply a highly oversimplified version of natural selection to explain what you observe in everyday, and then treat the result as obviously true. It's almost like sympathetic magic.

[tolbiny]

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I think all the evolutionary arguments for old age (tribes that had grandparents were fitter, etc) are nonsense.

The man reason we live to an old age because our bodies have enough vitality in youth to last for a number of years after our prime. No different to a car whose components generally work for a 10 year lifespan but is still going after 40.

[/ QUOTE ]

But an important part of that would have to be that designing bodies with this extra vitality comes at no cost over designing less vital bodies. That may very well be true: the adaptations that were selected for in other niches and for other conflicts might just have, as a side effect, an increase in 'vitality.'

But its not exactly obvious that this is the case. It seems, perhaps superficially, that building a body that is capable of living 120 years takes more resources than building one that lasts 40 years, and these resources are wasteful, unless you can posit some benefit to grandparents. So, we've either got to explain how the resources required are identical or explain the benefit that offsets the costs. Madnak and others are trying to do the latter, and it seems like you are saying the former?

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To begin with all lives are not lived the same. Age isn't just the adding of years, its the adding of stresses (physical, emotional, psychological). If you were able to live 40-50 years just fine under average conditions but no more your line would be wiped out when conditions were harsher and you had to do more work to survive and procreate each year. In poker terms your Risk of Ruin would be quite high if you were incapeable of living past a certain age.

[vhawk01]

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I think all the evolutionary arguments for old age (tribes that had grandparents were fitter, etc) are nonsense.

The man reason we live to an old age because our bodies have enough vitality in youth to last for a number of years after our prime. No different to a car whose components generally work for a 10 year lifespan but is still going after 40.

[/ QUOTE ]

But an important part of that would have to be that designing bodies with this extra vitality comes at no cost over designing less vital bodies. That may very well be true: the adaptations that were selected for in other niches and for other conflicts might just have, as a side effect, an increase in 'vitality.'

But its not exactly obvious that this is the case. It seems, perhaps superficially, that building a body that is capable of living 120 years takes more resources than building one that lasts 40 years, and these resources are wasteful, unless you can posit some benefit to grandparents. So, we've either got to explain how the resources required are identical or explain the benefit that offsets the costs. Madnak and others are trying to do the latter, and it seems like you are saying the former?

[/ QUOTE ]
Vitality and spare energy in youth is a huge advantage in survival and sexual selection. Immune systems that are capable of warding off more disease in youth will no doubt enable a person to better avoid disease in older age. Heart muscles that can take prolonged strain in youth would no doubt outlast those that can't, all things being equal.

There's also the fact that the longer lifespans mean more opportunities for reproduction. Even men of Sklansky's age occasionally get one away in a healthy female of reproductive age. Perhaps female longevity is piggybacked on the genes that cause male longevity? Who knows

Besides, why would evolution design us to suddenly die when we're 40? It makes no sense. From what I've seen bodies carry on for as long as it can before they wear out.

I have no doubt that there are species of non or less social animals who would live past viable breeding age if kept stimulated.

[ QUOTE ]
That might be true but only if there was no significant evolutionary advantage either way.

chez

[/ QUOTE ]
Many human traits are no doubt byproducts of other mechanisms. For example, our strong social bonds may well be a byproduct of some mutation that caused longer periods of infancy and weaker offspring. Or a grouping of traits causing more gray matter and longer brain development times. The cause of social behavior may not have been the direct advantages it provided to groups, but rather of byproduct of more effect rearing patterns, such as the development of intelligence and knowledge enhancing bonds between individual mothers and children. Just because we have some trait doesn't mean that that specific trait provided an evolutionary advantage.

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I pretty much agree with you, but I wanted to answer one thing. In regards to 'why would we be programmed to die at age 40,' while this probably isn't the case, it certainly isn't impossible. When you look at selection as effecting the gene level, having non-replicators sitting around, sucking up resources, would be something that would be selected against. So, if you had a trait for 'dying at age 40,' it wouldn't confer any specific reproductive advantage, but also no disadvantage, and if it was able to become more prevalent in the species, it would start to confer an advantage. A society where everyone dies after reproducing wastes less resources.

Of course, in humans, our adolescence is so extended that dying 'right after reproducing' isn't really beneficial. But look at flies. Doesn't it make sense to view them as 'designed' to die shortly after reproduction?

[chezlaw]

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Just because we have some trait doesn't mean that that specific trait provided an evolutionary advantage

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No but if a trait provides a significant evolutionary advantage then we would likely have it.

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Besides, why would evolution design us to suddenly die when we're 40? It makes no sense. From what I've seen bodies carry on for as long as it can before they wear out.


[/ QUOTE ] I think that may be incorrect. Maybe its some myth but don't some cells stop reproducing after a number of generations?

chez

[Phil153]

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Just because we have some trait doesn't mean that that specific trait provided an evolutionary advantage

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No but if a trait provides a significant evolutionary advantage then we would likely have it.

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Nonsense.



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Besides, why would evolution design us to suddenly die when we're 40? It makes no sense. From what I've seen bodies carry on for as long as it can before they wear out.


[/ QUOTE ] I think that may be incorrect. Maybe its some myth but don't some cells stop reproducing after a number of generations?

chez

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From what I understand the jury is very much out. There are a heap of competing theories on why most animal cells age. I'm in the "accumulated errors" camp. RDuke?