Evolutionary Question - Old Age and Natural Death

[Raziaar]

It's a simple question really, but undoubtedly a very difficult and complex answer. How does old age and death factor into evolution? What is the purpose of nature to have created organisms that wither away and self destruct in time, rather than continue on indefiniately at a certain maturity point(everlasting life until unnatural death)?

Its just a little confusing to me. Hope somebody can shed light on it. I'm asking for more than the biological facts that cells deteriorate. I'm trying to figure out why they do, and why they do at certain rates compared to other organisms. Or even why they do to begin with.

Why do certain species live longer than others, or in some cases, significantly longer(such as trees)?

*note: this isn't about religion or anything like that. Just very curious*

 

[15357]

Perhaps its because we change faster and must die out for the brand new generation?

 

[Raziaar]

Hmmm. I found this interesting article.

Microbes Are Immortal, So Why Aren't Humans?

 

[Beerdude26]

Because we haven't perfected ourselves. Evolution requires new organisms to work on. So we are limited in our lifespan. Trees, on the other hand, have perfected themselves. They are practically tanks, hard to be destroyed and will live for very, very long as long as there is food. Ants have chosen for strength in numbers rather than individuals. They can build huge nests (looking at their size) in very short amounts of time. They are probably still perfecting themselves to live longer, although they tend to risk their own life for the horde :O )

 

[CrazyHarij]

I think it's part of the survival of the fittest thing. The individuals that manage to survive and breed during their allotted time will be the best suitors for bringing on the species. The ones who don't suceed die relatively quickly.

Plus you need to consider back in the days when it was all about survival few humans made it to a natural death and not being killed by predators or some sort of disease. And we didn't live for as long back then, so it was even more intense.

Trees have a different way of breeding. They live for very long and spread their leaves, seeds and such and can spread very very far, while being at the same spot.

And correct me if i'm wrong, but I really don't think it'd be possible to live forever (without artificial/scientific help in the near future), cell structures don't work that way the human organism is amazing enough as it is already.

Besides, think of this; if we needed to live longer for our species to survive, we would. The way we are now is because that's the kind of human being that made it through all the struggles when other were victims of the competition.

 

[15357]

The above 2 just summed up what I had in mind but couldn't translate/say.

 

[Cormeh]

By nature, we reproduce too much to have unlimited lifespans. Death is just as natural as life.

 

[RandomX]

If we didn't die naturally, the earth would be overcrowded and we'd have to kill people off just to have some room. It's because we reproduce so much that this happens, so that we do not overpopulate the earth and destroy it naturally! We're doing it artificially, but that's besides the point.

 

[Nat Turner]

If we didn't die naturally, the earth would be overcrowded and we'd have to kill people off just to have some room. It's because we reproduce so much that this happens, so that we do not overpopulate the earth and destroy it naturally! We're doing it artificially, but that's besides the point.

I don't think that's actually a problem. The Earth cannot really be destroyed by anything short of nukes or asteroids, because there is a continual surplus of energy from the sun. Overpopulation solves itself.

 

[CyberPitz]

I've been contemplating this since I was a kid in science class.

I always thought of those off the wall things that only a few, if anybody could solve.

Like, I asked my dad one day, "Why do I see out of these eyes? Why not someone elses..and will I change into someone else's eyes when I die?"

He wasn't the kind of dad that just thrusted religion upon me..so he said, "I'm not sure, Paul...you'll have to find out in time I guess!"

 

[RandomX]

I don't think that's actually a problem. The Earth cannot really be destroyed by anything short of nukes or asteroids, because there is a continual surplus of energy from the sun. Overpopulation solves itself.

And with the way Bush is going, do you think Nukes are too far off?

 

[Nat Turner]

I've been contemplating this since I was a kid in science class.

I always thought of those off the wall things that only a few, if anybody could solve.

Like, I asked my dad one day, "Why do I see out of these eyes? Why not someone elses..and will I change into someone else's eyes when I die?"

He wasn't the kind of dad that just thrusted religion upon me..so he said, "I'm not sure, Paul...you'll have to find out in time I guess!"

Yeah, it's quite possible either way. Science isn't advanced enough to rule out much yet.

 

[Nat Turner]

And with the way Bush is going, do you think Nukes are too far off?

Nope. I expect a nuclear war in my lifetime.

 

[short recoil]

It's like asking why don't we still use 1940's cars on the motorway.
If humans lived forever, they could continue to breed giving the same genetics day after day....evolution would stop.

It's an advancement of the gene pool, hopefully by natural selection the weak perished before they could breed and the strong prevailed and passed on their genes, the strongest of the young should do the same.

The time our bodies live for is dependant upon our life cycle complexity.
It was advantageous for us to live for an average age of 50 or whatever (minus illness) so that's how we evolved.

A bacteria that lived 50 years and reproduced every year would be useless therefore it does not exist.

Nope. I want a nuclear war in my lifetime.

If people say they expect a nuke war, they want one.
We all know you wanna drive around in a post apocalypse dodge charger with supercharger sticking out bonnet and a m2hb bolted to the roof.

 

[Sulkdodds]

All dat shiz above, yo. Plus it's probably not actually possible for a biological machine of such incredible impossible complexity and intricacy as the human body to last too long without breaking down.

 

[Bait]

Death is your body's defence against serious sicknesses when you age. As you get older, your body is more prone to getting terribly sick, like with cancer, and as a defence cells will start to die. Too many die, then you die. Or something like that.

 

[Ren.182]

Well, about other species living shorter lives... that's down to the way they work (biologically). Like dogs, for example, their hearts beat like 7 times faster than ours... or something like that. And lets say the average dog lives to 12 years? Time that by 7 and thats 84 years... bit above the average human age, but not far off.

 

[OvA]

Not to mention overcrowding and famine.

 

[short recoil]

Well, about other species living shorter lives... that's down to the way they work (biologically). Like dogs, for example, their hearts beat like 7 times faster than ours... or something like that. And lets say the average dog lives to 12 years? Time that by 7 and thats 84 years... bit above the average human age, but not far off.

"Most parrot and parrot-like birds have a heart rate of around 260-290 beats per minute"

And parrots can out live us, put it this way, churchils parrot is still alive 104 years old

Life "speed" has nothing to do with heart rate.

It is down to a body being able to repair itself, after time the body loses this ability and weakens as someone else said.
Wear and tear can be repaired just as a child grows, it's just the fact we lose the ability to self repair.
Give us stem cells and we could live until the day something kills us.

 

[Ren.182]

"Most parrot and parrot-like birds have a heart rate of around 260-290 beats per minute"

And parrots can out live us, put it this way, churchils parrot is still alive 104 years old

Life "speed" has nothing to do with heart rate.

I have been proven wrong by the god of health and body.

Feel like a right n00b now

 

[Fliko]

Because we haven't perfected ourselves. Evolution requires new organisms to work on. So we are limited in our lifespan. Trees, on the other hand, have perfected themselves. They are practically tanks, hard to be destroyed and will live for very, very long as long as there is food. Ants have chosen for strength in numbers rather than individuals. They can build huge nests (looking at their size) in very short amounts of time. They are probably still perfecting themselves to live longer, although they tend to risk their own life for the horde :O )

Pretend Cells are like an old fashioned timebomb, the string is burning slowly, and when it disappears, the cells choose to stop producing. (Kinda like a BOOM!). There is a theory that scientists can replicate this 'string', and cause cells to live immortally, 'hence, you can't die from age, your cells will multiply for as long as you wish. Atleast, theoritically, they don't know long-term affects. I imagine the heart might stop, which would need the cause for artifical art, and perhaps lungs and live.
EDIT: You got to remember, only so much things can fit on one planet. It is possible we might evolve to live forever if we find more planets. Possible, but unlikely in my opinion.

 

[Raziaar]

If we didn't die naturally, the earth would be overcrowded and we'd have to kill people off just to have some room. It's because we reproduce so much that this happens, so that we do not overpopulate the earth and destroy it naturally! We're doing it artificially, but that's besides the point.

But how could our evolutionary process POSSIBLY be in tune with the size of the earth and whether or not we would overcrowd. Sure, I can understand if the world was already overcrowded. But still, thats something I doubt evolution could pick up on. Evolution isn't psychic... If it were, everything would be perfectly adapted to everything.

 

[Apos]

There actually are some pretty good ideas as to why we die. They are fairly complex though, so I'd suggest getting a good book on the subject. But the short of it is that species that reproduce a lot (or put a lot of effort into raising young) at the expense of their own lives tend to be more successful than those that live with long periods of stasis. Evolutionary adaptation is much more flexible when there's a new generation every few years as opposed to the same old rigid designs over and over. Also, given that most creatures would end up dying anyway from external causes, there's not much evolutionary benefit to bothering to keep something alive long after its reproduced.

Again, the reasons are much much more complicated (and the calculus is nto the same in every species) so I'd suggest a good book on the subject (and there are many available).

 

[dream431ca]

There actually are some pretty good ideas as to why we die. They are fairly complex though, so I'd suggest getting a good book on the subject. But the short of it is that species that reproduce a lot (or put a lot of effort into raising young) at the expense of their own lives tend to be more successful than those that live with long periods of stasis. Evolutionary adaptation is much more flexible when there's a new generation every few years as opposed to the same old rigid designs over and over. Also, given that most creatures would end up dying anyway from external causes, there's not much evolutionary benefit to bothering to keep something alive long after its reproduced.

Again, the reasons are much much more complicated (and the calculus is nto the same in every species) so I'd suggest a good book on the subject (and there are many available).

Actually we die because oxygen kills us...breaks down the cells in our body overtime, that's why we get old..and no I'm not lying and this is not a joke.

 

[Fliko]

Actually we die because oxygen kills us...breaks down the cells in our body overtime, that's why we get old..and no I'm not lying and this is not a joke.

That overthrows the whole cell reproduction theory. Our cells reproduce, you can't break them all down, most of them are replaced over night with new cells.

 

[Raziaar]

Hey Apos, can you answer my thing above the post you made? I hear people say all the time that critters will evolve differently, such as humans reproducing less, based on overpopulation.

That would be completely impossible with evolution, would it now? How could it have a 'sixth sense' if you will, to guage the capacity of the earth, and then act upon it.

 

[Anthraxxx]

There is no theory of evolution, just a list of creatures Chuck Norris allows to live.

 

[Murray_H]

I want longer telomeres, then I'll be immortal!

 

[Apos]

Hey Apos, can you answer my thing above the post you made? I hear people say all the time that critters will evolve differently, such as humans reproducing less, based on overpopulation.

Well, a species suddenly reproducing less isn't itself necessarily evolution at work, though it might be an instinct or reaction that evolved (and it certainly makes sense for that sort of strategy to evolve). Many animals actually do have different reproductive strategies based on the amount of resources available or what the environment is like (some so radical that they involve changing sexes!). Again, the differences between different animals are almost too many to generalize about. However, I'm not sure if this is really what you were getting at. RandomX's statement that you were responding to is sort of confused and vague. The underlying evolutionary reasons why, at least in our area of the tree of life, that we die are many and complex, but they certainly don't involve foreknowledge of the negative consequences (especially since we many times in even modern history have overpopulated certain areas, or had famines where scarce resources for too many people caused massive death)

That would be completely impossible with evolution, would it now? How could it have a 'sixth sense' if you will, to guage the capacity of the earth, and then act upon it.

It wouldn't, but that doesn't mean that there aren't natural feedback mechanisms at play. The most basic does deal with overpopulation: when there are lots of resources (food, shelter, etc.) the population expands. But it only expands to the point where there is fierce competition for resources, and at that point not every creature can survive and so many do die off. Sometimes, because of the lag in generations, a population explosion can cause extinction. For instance, if a certain population eats only one kind of food (another animal) if it's population spikes too high, the competition for that food can cause it to go extinct... which then causes a crash in the population (or, at worse, extinction there too). That's one reason why being flexible in your diet is often a more robust long term strategy than only eating one kind, and so species that are more flexible in their diets often outlive those that are too rigid in times of rapid change and extinctions. None of this is planned per se, but rather a larger scale result of evolution.

For an intro into these sorts of discussions (population genetics and population dynamics is a whole field unto its own in biology), I'd suggest a book called "Darwin's Ghost" which should be bargin bin priced by now or at the local library.