Immortality?

A Neurotic

Found this article very interesting. An animal with some sort of perpetual rejuvenation mechanism.

I find the whole mystery of aging fascinating. It's so fundamental to us that it's easy to overlook, but, biologically, aging and dying are nowhere near properly understood. It seems quite obvious that the weakening and death of individuals with age are beneficial for a species on the whole, but is it possible that evolution could take this bigger picture into account?

asdasd

yep. dying is built in, as is aging. Since our cells renew every 7 years there is no reason for us not to be immortal except for the evolutionary advantage to getting a new generation with mutations. for that, the old generation has to die off.

A Neurotic

But how can an individual evolve in a manner that doesn't benefit the individual, but does benefit the species?

asdasd

Thanks for the link. It's pretty interesting, isn't it? I was so intrigued that I searched around and found another link that sheds a bit more light on the phenomenon.

asdasd wrote: »

yep. dying is built in, as is aging. Since our cells renew every 7 years there is no reason for us not to be immortal except for the evolutionary advantage to getting a new generation with mutations. for that, the old generation has to die off.

I've never heard of that before? It's an interesting theory, I guess it makes some logical sense; but to me it seems to be practically impossible. Any sources for that view? I'm intrigued.

A Neurotic wrote:

But how can an individual evolve in a manner that doesn't benefit the individual, but does benefit the species?

I'm not necessarily sure of the validity of the claim that it's an evolutionary advantage to die, thus leaving the world to our progeny. It has always been my understanding that ageing, and thus death, were a direct result of the action of free radicals in our bodies (that's the current theory, anyway). I don't think it has anything got to do with it being an evolutionary advantage.

As for an individual evolving in a manner that benefits its species but not itself? I can't think of any examples of that off the top of by head. It seems a bit contradictory to me, too.

asdasd

It has always been my understanding that ageing, and thus death, were a direct result of the action of free radicals in our bodies (that's the current theory, anyway). I don't think it has anything got to do with it being an evolutionary advantage.

Free radicals have no damaging effects on humans from the age 0 to 25. During that time everythig gets better, expoentially better. Then an immediate decline with little plateau.

The correct term here is Senescence

asdasd

asdasd wrote: »

Free radicals have no damaging effects on humans from the age 0 to 25. During that time everythig gets better, expoentially better. Then an immediate decline with little plateau.

The correct term here is Senescence

In all my reading about evolution I've never heard of that, odd!

Thanks for the link, I'll be sure to look into it more.

asdasd

As for an individual evolving in a manner that benefits its species but not itself? I can't think of any examples of that off the top of by head. It seems a bit contradictory to me, too.

Oh thats a common theory - group evolutionary theory.

asdasd

Cool, forum this, BTW.

A Neurotic

-JammyDodger- wrote: »

I'm not necessarily sure of the validity of the claim that it's an evolutionary advantage to die, thus leaving the world to our progeny. It has always been my understanding that ageing, and thus death, were a direct result of the action of free radicals in our bodies (that's the current theory, anyway). I don't think it has anything got to do with it being an evolutionary advantage.

I've been reading around [sounds more impressive than "I looked it up on wikipedia", no?] and there are scores of theories on the matter. I'm not sure why Evolution stuck out in my mind earlier. The concept that I had in mind was this one:

Essentially, aging is therefore the result of investing resources in reproduction, rather than maintenance of the body (the "Disposable Soma" theory)

Some say it's genetically programmed as a means of fighting cancer. Some say it's the accumulation of damage to or misrepair of DNA. All I know is, I'm out of my depth :pac:

A Neurotic

asdasd wrote: »

Oh thats a common theory - group evolutionary theory.

It's the [hopefully not too complicated] mechanism of this that intrigues/confuses me. I just don't see how on earth it can happen. Back to wikipedia I go...

asdasd

asdasd wrote: »

Oh thats a common theory - group evolutionary theory.

But an individual in the group doesn't evolve in a manner that's not beneficial to itself; it evolves in a manner that's beneficial to its group and, in doing so, its evolution is beneficial to itself. (The question posed was for evolution that benefited another-individual/group but didn't benefit the individual itself).

Although, I know very little about group selection.

asdasd

Well, for example, an overweaning case of altruism may not be benefical to some members of a given population ( the nice guy who gets pushed around and cheated, leading to less status, and less reproductive success), but to better group success.

Or someone willing to die for his in-group - that is go to war - before he gets a chance to reproduce. It is very hard to explain that in terms of a seflish gene. You can try it culturally ( i.e. people are bullied into it) but that does not negate the fact that the foolishly brave are reproductively not successful but benefit the group. The cowardly survive.


This traits are never universal, however, since reckless bravery would get everyone killed, and conversely were everyone cowardly ( or less reckless) the group would lose the war.
This has been explained mathematically. Too late to post the wiki articles :-)

Ostrom

-JammyDodger- wrote: »

But an individual in the group doesn't evolve in a manner that's not beneficial to itself; it evolves in a manner that's beneficial to its group and, in doing so, its evolution is beneficial to itself. (The question posed was for evolution that benefited another-individual/group but didn't benefit the individual itself).

Although, I know very little about group selection.

I was just reading a paper on that (group evolution) about the nature of altruism as a factor in evolutionary trajectories in humans. Left it in work, ill post up the reference tomorrow. Think it may have been in human ecology

asdasd - was that specifically a Dawkins reference?

asdasd

efla, you mean selfish gene? Yes, Dawkins is not a fan of Group evolutionary theory, but I think he is wrong.

@ A Neurotic: You're not alone when you say you're out of your depth.:pac:

@ asdasd: We're not disagreeing, anyway. Now that you mention specific cases such as altruism and fighting for death etc. it's all refreshing my mind. I was trying to think of a specific examples, and in doing so forgot about general examples such as altruism.

@ elfa: I'd love to see that paper. Group selection is one of my less knowledgeable areas when it comes to evolution.

Ostrom

asdasd wrote: »

efla, you mean selfish gene? Yes, Dawkins is not a fan of Group evolutionary theory, but I think he is wrong.

I dont know a lot about it, I'm trying to get into it more. Most of what I have come across is from sociological commentaries on Dawkins that talk loosely about altruism in social context. How is group evolutionary theory argued for?

tallaght01

asdasd wrote: »

our cells renew every 7 years .

asdasd wrote: »

Free radicals have no damaging effects on humans from the age 0 to 25

What's your source for the above statements?

asdasd

The every seven years claim has been out there for a while . WikiAnswers has more info.

The point I was making about Free radicals is simple. If they were to have a deleterious affect on humans i.e. cause signs of aging - then it would start to happen from age zero. It doesn't. And senescence/aging happens at different rates across the animal kingdom, even across mammals. A bat can live to 30, a mouse only lives to 3 at best.

If free radicals had any affect on aging it would be constant across the animal kingdom, and obvious from birth.

what happens instead from birth, is that the human body continues to grow, get fitter, more muscular and more endurant from age 0 to about 25 ( maybe younger) and then there is a slowish decline. The decline is not that slow, however, as very few athletes are working a mere 10 years later. If they are they have slowed down, and are near the end of their careers. Isn't this obvious?

if free radicals are having any affect it is overcome by that part of the aging process which takes us from mewling infant to Lions Prop Forward. Then our bodies do not plateau, but start to disintegrate.

Compare that with a non-organic entity - like a car. A car - at zero - just off the production line is at it's best, not at 25 years.

asdasd

Some information on Group Evolutionary Theory at wiki.

darjeeling

asdasd wrote: »

Well, for example, an overweaning case of altruism may not be benefical to some members of a given population ( the nice guy who gets pushed around and cheated, leading to less status, and less reproductive success), but to better group success.

Or someone willing to die for his in-group - that is go to war - before he gets a chance to reproduce. It is very hard to explain that in terms of a seflish gene. You can try it culturally ( i.e. people are bullied into it) but that does not negate the fact that the foolishly brave are reproductively not successful but benefit the group. The cowardly survive.


This traits are never universal, however, since reckless bravery would get everyone killed, and conversely were everyone cowardly ( or less reckless) the group would lose the war.
This has been explained mathematically. Too late to post the wiki articles :-)

Group selection did fall from favour as the ideas of gene-level selection and inclusive fitness came to the fore. Under inclusive fitness models, altruism can evolve if it's directed towards relatives; the closer the relative, the greater the level of gene sharing and hence expected level of altruism. This is kin selection rather than group selection.

There's also the possibility of reciprocal altruism, where individuals re-encountering each other remember and return favours. In practice, these individuals are often kin, meaning that kin selection may be acting too.

There is a current partial revival by some of group selection models, especially in the area of 'eusociality' (seen in e.g. bees, ants and the spectacularly ugly naked mole rats), where individuals forgo their own chance of breeding in favour of colony queens. Others dispute that group selection is acting, and say that what's really going on is kin selection (see e.g. this recent PNAS paper).

Edit: As a happily relevant aside, the naked mole rat is the longest-lived rodent. It's venerability is put down to its low metabolism and consequent low oxidative stress.

Faith

I read that article, and it led me to this: http://abcnews.go.com/2020/Health/Story?id=7880954&page=1

This child is 16 years old, weighs 16lbs and is 30 inches long. She has barely developed at all from infancy, never learning to talk or walk. She got very ill on many occasions and mysteriously and suddenly recovered from them all. Geneticists have found no abnormalities, and doctors are baffled. Is she immortal? Can studying her unlock the mystery of aging? It's completely bizarre!

tallaght01

asdasd wrote: »

The every seven years claim has been out there for a while . WikiAnswers has more info.

The point I was making about Free radicals is simple. If they were to have a deleterious affect on humans i.e. cause signs of aging - then it would start to happen from age zero. It doesn't. And senescence/aging happens at different rates across the animal kingdom, even across mammals. A bat can live to 30, a mouse only lives to 3 at best.

If free radicals had any affect on aging it would be constant across the animal kingdom, and obvious from birth.

what happens instead from birth, is that the human body continues to grow, get fitter, more muscular and more endurant from age 0 to about 25 ( maybe younger) and then there is a slowish decline. The decline is not that slow, however, as very few athletes are working a mere 10 years later. If they are they have slowed down, and are near the end of their careers. Isn't this obvious?

if free radicals are having any affect it is overcome by that part of the aging process which takes us from mewling infant to Lions Prop Forward. Then our bodies do not plateau, but start to disintegrate.

Compare that with a non-organic entity - like a car. A car - at zero - just off the production line is at it's best, not at 25 years.

That's fine, as long as we accept it's mostly speculation.

Ostrom

Found it:

Field, Scott A., 2000. Human Altruism: Group Selection Should Not Be Ignored, Journal of Social and Evolutionary Systems, 2 (2): 125-131

Interesting and brief piece with comments on meme vs gene transmission and its applicability in group context. I'm not sure if this is the best place to put it, as it ties in closely with the Hawking discussion. In terms of group selection, Field is suggesting that the human group should be considered as an analystical unit due to its ability to engage in purposive, planned action thereby conferring competitive advantage.

What interested me most about this, was his suggestion as to why the notion of group selection fell out of favour (and this seems to be a recurring theme in any social/natural science debate) - the analytical unit.

Early anthropologists have focused on group action in an historical-evolutionary context (I'm just referring to Morgan and Maine and the idea of evolutionary models of barbaric - civilised - modern: the approach may have fallen out of favour, but I agree that human societies do to some extent show such broad levels of development - he may have pre-empted Marx by locating these changes at the economic level). I think its an interesting approach to revisit some of the ideas and to see the parallels with what Hawking is describing - they deal with the same issues of group action - technological development, suppression of the free-rider, control through sanction and punishment, (with Hawking emphasising the former).

Anyway, the impression I'm getting from the paper is that the discarding of group-selection models results more from a bias against ethnological data, with a preference for discrete empirical units such as the meme. I think a current weakness of the group selection model is possibly in its inability to bridge both - to recognise the role of each at different levels in the reckoning of competitive advantage - but perhaps someone more widely read could correct me on this. I dont feel that authors coming from a natural science background deal too well with social forms and social change, so this is interesting as a possible area where one could inform the other

jumpguy

asdasd wrote: »

The every seven years claim has been out there for a while . WikiAnswers has more info.

The point I was making about Free radicals is simple. If they were to have a deleterious affect on humans i.e. cause signs of aging - then it would start to happen from age zero. It doesn't. And senescence/aging happens at different rates across the animal kingdom, even across mammals. A bat can live to 30, a mouse only lives to 3 at best.

If free radicals had any affect on aging it would be constant across the animal kingdom, and obvious from birth.

what happens instead from birth, is that the human body continues to grow, get fitter, more muscular and more endurant from age 0 to about 25 ( maybe younger) and then there is a slowish decline. The decline is not that slow, however, as very few athletes are working a mere 10 years later. If they are they have slowed down, and are near the end of their careers. Isn't this obvious?

I'm just thinking here but perhaps free radicals do effect us from birth, but only start to catch up with us as we get older because:
1 - Our body has been suffering damage since birth.
2 - Our bodies slow down, causing our defences against free radicals to fail.
3 - Gene damage accumulation.
4 - Apoptosis due to this "group evolution" theory.


Miles outta my depth here too

On a different level, if we lived forever, would the world not become abit too much to bear? You'd have to watch your friends and family die, all the pains and angsts of life, over and over. If everyone lived forever...overpopulation and sheer boredom would be too much.

asdasd

That's fine, as long as we accept it's mostly speculation.

Um, no it isnt. The primary cause of aging is built in senescence. I already posted that link.

There are diseases where kids age rapidly. Do they attract and absorb more free radicals?

Assuming you are a doctor, you conform my prejudices about most Doctors. It is a academic disicpline largely learned by rote - with the exception of medical research students and professors, doctors need be, by definition, conservative. They keep to what they learned until someone tells them that isnt true, wins a nobel prize, and then the general uniformity of medical opinion changes. Like the embarrassment about what causes ulcers.

Seriously, aging is in-built and evolutionary.

tallaght01

asdasd wrote: »

Um, no it isnt. The primary cause of aging is built in senescence. I already posted that link.

There are diseases where kids age rapidly. Do they attract and absorb more free radicals?

Assuming you are a doctor, you conform my prejudices about most Doctors. It is a academic disicpline largely learned by rote - with the exception of medical research students and professors, doctors need be, by definition, conservative. They keep to what they learned until someone tells them that isnt true, wins a nobel prize, and then the general uniformity of medical opinion changes. Like the embarrassment about what causes ulcers.

Seriously, aging is in-built and evolutionary.

Oh jesus.

So, where's the evidence that free radicals do know harm to youngsters? As a paediatrician, I'm amazed at that claim!! What about iron toxicity free radical toxicity. There's a multitude of problems caused by free radical formation in young people. Again, I'm not sure what you're claiming here. First yo say they don't harm young people, then you give examples of where they do. But the reality is that the role of free radical formation in human decline is just theory.
Free radicals harm everyone. The fact that we age is no proof of free radical pathogenesis.

The other stuff you talk about is also speculation. Cells replicate at a rate that is dependent on the cell type. It doesn't take 7 years for a a small bowel epithelial cell to replicate. I have no idea where that point was going.

My name is URL

Great thread.

For anyone interested, you should look into the work of Aubrey de Grey, particularly his book The Mitochondrial Free Radical Theory of Aging, which he wrote in 1999

Prof.Badass

asdasd wrote: »

Um, no it isnt. The primary cause of aging is built in senescence. I already posted that link.

There are diseases where kids age rapidly. Do they attract and absorb more free radicals?

Maybe their bodies are less able to deal with free radicals and thus age faster.

btw, I thought someone would have mentioned resveratrol by now.

asdasd

Maybe their bodies are less able to deal with free radicals and thus age faster.

That would be built in senescence

asdasd

There's a multitude of problems caused by free radical formation in young people. Again, I'm not sure what you're claiming here. First yo say they don't harm young people, then you give examples of where they do. But the reality is that the role of free radical formation in human decline is just theory.

I didnt give an example of where "they did". That is an assumption you make, a priori, that Free Radicals cause aging. The children who age faster are subject to the same amount of Free Radicals as everybody else, and age faster because their genetic bodyclock makes them age faster. the other patholigies you mentioned - where free radicals affect some children, must have genetic factors as underlying cuases since it clearly is a small subset of children affected.

Free radicals have some affect, but the underlying cause is built in senescence.

I think people are so used to aging, that they miss the woods for the Trees.

At 0 a baby is helpless. At 25 he is a Lions Prop Forward.

Clearly everything - in the non-pathological cases - has gotten better. Better muscles, memory, recall, strength, etc. So cell division and aging from 0 - 25 are not just benign but massively beneficial to the human ( and most other animals although very few are born as helpless as us). From then on the human being begins to decline, and that may cause Free Radicals to have more effect, but decline is built in.

Could we make ourselves immortal then? Yes, I think so, or at least stop seneseance.

Other lifestyle related diseases - heart conditions and cancer - could still happen even if we "turned the clock off" at 25 because arteries could still be clogged, and cel division continue. And people will die from external factors.

I think that it is theoretically possible to fight aging though.

asdasd

Here is a blog about some immortal animals - well with little or no seneseance.

health warnings apply. It is a blog on eOpinions, and she doesnt seem to be an expert,

EDIT: Of course it is hard for us to tell, being mortal, if a animal is immortal or really slow at aging. The Hydra's may or may not age, or they may be aging too slowly for us to tell.

tallaght01

asdasd wrote: »

I didnt give an example of where "they did". That is an assumption you make, a priori, that Free Radicals cause aging. The children who age faster are subject to the same amount of Free Radicals as everybody else, and age faster because their genetic bodyclock makes them age faster. the other patholigies you mentioned - where free radicals affect some children, must have genetic factors as underlying cuases since it clearly is a small subset of children affected.

Free radicals have some affect, but the underlying cause is built in senescence.

I think people are so used to aging, that they miss the woods for the Trees.

At 0 a baby is helpless. At 25 he is a Lions Prop Forward.

Clearly everything - in the non-pathological cases - has gotten better. Better muscles, memory, recall, strength, etc. So cell division and aging from 0 - 25 are not just benign but massively beneficial to the human ( and most other animals although very few are born as helpless as us). From then on the human being begins to decline, and that may cause Free Radicals to have more effect, but decline is built in.

Could we make ourselves immortal then? Yes, I think so, or at least stop seneseance.

Other lifestyle related diseases - heart conditions and cancer - could still happen even if we "turned the clock off" at 25 because arteries could still be clogged, and cel division continue. And people will die from external factors.

I think that it is theoretically possible to fight aging though.

So, to go back to the point I made, you agree it doesn't take cells 7 years to regenerate, and free radicals can harm us at a young age?

CerebralCortex

asdasd wrote: »

Um, no it isnt. The primary cause of aging is built in senescence. I already posted that link.

There are diseases where kids age rapidly. Do they attract and absorb more free radicals?

Assuming you are a doctor, you conform my prejudices about most Doctors. It is a academic disicpline largely learned by rote - with the exception of medical research students and professors, doctors need be, by definition, conservative. They keep to what they learned until someone tells them that isnt true, wins a nobel prize, and then the general uniformity of medical opinion changes. Like the embarrassment about what causes ulcers.

Seriously, aging is in-built and evolutionary.

Nope it really isn't and from what I've read here sens.org and other sources the scientific concencus is the opposite. Mainly because the only selection that matters is for replication. We're brilliant at replicating but inadequate at self maintenance. IMO I don't care about being immortal, aging is disgusting and I don't think anyone really looks forward to it I know I'd rather not do it if possible. I think it will be possible.

tallaght01

tallaght01 wrote: »

So, to go back to the point I made, you agree it doesn't take cells 7 years to regenerate, and free radicals can harm us at a young age?

I'm not sure if asdasd was refering to this, but I'll say it anyway. I've read once that it takes an organ 7 years to completely regenerate (i.e. for every cell to be completely replaced). I'm not sure of the validity of this claim -- 7 years seems like an arbitrarily chosen number -- but perhaps it's what asdasd is referring to.

A Neurotic

I'm not sure how valid a source this is, but I seem to recall reading a similar 7-year claim in Bill Bryson's Short History of Nearly Everything.

tallaght01

My understanding of that claim is that it's been around a LONG time, but no one has ever been able to prove it.

It doesn't make sense, as organs are all different sizes, and their cells are all different.

To my understanding, there's nothing in the scientific literature to prove that wrong.

Has anyone got a reference that's not an opinion piece?

tallaght01

tallaght01 wrote: »

Has anyone got a reference that's not an opinion piece?

I have no references, anyway (by the way, I'm not claiming it to be true -- 7 years just seems too arbitrary of a number -- as I've never seen any evidence, but I've seen it written in a few pop. science books, which is probably how the idea propagates).

asdasd

The seven year idea is not necessarily true. However human cells do regenerate.

Nope it really isn't and from what I've read here sens.org and other sources the scientific concencus is the opposite

the opposite of what, exactly?

CerebralCortex

asdasd wrote: »

The seven year idea is not necessarily true. However human cells do regenerate.



the opposite of what, exactly?

The concencus afaik is that aging comes from a lack genetic information not the presence of it. Genetic evolution provides us enough to stay alive long enough to reproduce aging is just the damage and junk that accumalates over time which we are incapable to deal with. I really urge you to read this http://sens.org/index.php?pagename=sensf_faq_challenging#nb6

Minder

Anybody have any thoughts on the ideas of Raymond Kurzweil.... clinical immortality is close - we just have to live long enough to see it.

The Singularity Is Near: When Humans Transcend Biology is a 2005 update of Raymond Kurzweil's 1999 book, The Age of Spiritual Machines and his 1987 book The Age of Intelligent Machines. In it, as in the two previous versions, Kurzweil attempts to give a glimpse of what awaits us in the near future. A movie with the same name is set to be released on September 1, 2009. Kurzweil's reasoning rests on the combination of four postulates:

1 A technological-evolutionary point known as "the singularity" exists as an achievable goal for humanity (the exact nature of the point is an arbitrarily high level of technology).

2 Through a law of accelerating returns, technology is progressing toward the singularity at an exponential rate.

3 The functionality of the human brain is quantifiable in terms of technology that we can build in the near future.

4 Medical advancements could keep a significant number of his generation (Baby Boomers) alive long enough for the exponential growth of technology to intersect and surpass the processing of the human brain.

CerebralCortex

Minder wrote: »

Anybody have any thoughts on the ideas of Raymond Kurzweil.... clinical immortality is close - we just have to live long enough to see it.

Interesting indeed, but I don't think either immortality or the singularity imho is as important and interesting as subject as SENS(stratagies for engineering senesence).

jumpguy

Back to the claims about cell regeneration taking 7 years (and I only read the first few posts on the debate). 7 years to me sounds like a baseless layman's claim. It's like claims of if you drop something on the floor it takes 5 seconds for it to become unsafe to eat. As Tallaght said, all organs are different sizes and are made up of different sorts of cells. Also, everyone is different, for example, an elderly person would have much slower regeneration and a younger person might have much faster.

If human immortality is indeed close (as in within 200 years), we'll destroy the planet. However, I think it's impossible. All we can do is slow down death, by medicine or leaving machines take over the function of an organ. The lower levels of death and higher birth rates we have has already overpopulated the Earth. Death is a built-in feature nessicary to secure the future of our species, and all others. It also provides food for plants...which are the beginning of all food chains.

asdasd

lets not get stuck on the seven years claim. Cells do regenerate. Thats enough.

CerebralCortex

jumpguy wrote: »

Back to the claims about cell regeneration taking 7 years (and I only read the first few posts on the debate). 7 years to me sounds like a baseless layman's claim. It's like claims of if you drop something on the floor it takes 5 seconds for it to become unsafe to eat. As Tallaght said, all organs are different sizes and are made up of different sorts of cells. Also, everyone is different, for example, an elderly person would have much slower regeneration and a younger person might have much faster.

Yep.

jumpguy wrote: »

If human immortality is indeed close (as in within 200 years), we'll destroy the planet.

By whose decree?

jumpguy wrote: »

However, I think it's impossible. All we can do is slow down death, by medicine or leaving machines take over the function of an organ.

jumpguy wrote: »

The lower levels of death and higher birth rates we have has already overpopulated the Earth.

Gross assumption here that people will have more kids if they live longer, when in fact if you look at western civilisation people are living longer and birth rates are slowing even declining. Ever hear of the concept that we're an aging population? Besides there is a clear resource distribution problem (thats an educated guess I'm making).

jumpguy wrote: »

Death is a built-in feature nessicary to secure the future of our species, and all others.

Not true.

jumpguy wrote: »

It also provides food for plants...which are the beginning of all food chains.

asdasd wrote: »

lets not get stuck on the seven years claim. Cells do regenerate. Thats enough.

Yes cells do regenerate when needed.

A Neurotic

CerebralCortex wrote:

Ever hear of the concept that we're an aging population? Besides there is a clear resource distribution problem (thats an educated guess I'm making).

Interesting side note: within 10 years, the global population of 65+ year olds will outnumber children under 5 for the first time in human history.

Article.

jumpguy

CerebralCortex wrote: »

Yep.



By whose decree?


Overpopulation. The population won't age and die. Just keep growing until demand exceeds our food supply


Gross assumption here that people will have more kids if they live longer, when in fact if you look at western civilisation people are living longer and birth rates are slowing even declining. Ever hear of the concept that we're an aging population? Besides there is a clear resource distribution problem (thats an educated guess I'm making).

The world is already overpopulated by humans. If oil were to dry up tomorrow, intensive farming would stop. We would not be able to sustain our current population. When animal populations exceeds what nature can supply without chemicals, I consider us overpopulated.
Many countries are now entering the second/middle stages of their demographic transition. Only a handful of countries in the world are at the end of the demographic transition. Don't kid yourself, just because population is static or slightly declining in some European countries, doesn't mean we're out of the woods.

Not true.

Fine, don't bother telling us what you think.

...

tallaght01

asdasd wrote: »

lets not get stuck on the seven years claim. Cells do regenerate. Thats enough.

Every schoolchild knows that cells don't last forever.

It was only your response:

asdasd wrote: »

Assuming you are a doctor, you conform my prejudices about most Doctors. It is a academic disicpline largely learned by rote - with the exception of medical research students and professors, doctors need be, by definition, conservative. They keep to what they learned until someone tells them that isnt true, wins a nobel prize, and then the general uniformity of medical opinion changes. Like the embarrassment about what causes ulcers.

that made me push the issue.

CerebralCortex

jumpguy wrote: »

Fine, don't bother telling us what you think.

I think I already did tell you what I think in post #39, but I'll try again. Aging is the acummulation of damage which eventually causes frailty and pathology due to the fact that we have inadequate mechanisms for dealing with the damage thus we die from amongst other things aging. Seems pretty simple to me. The suggestion that genetic evolution has made some kind of concious decision to build in a gene for rotting the body in my opinion suggests that you don't fully understand evolution and if I'm completely honest I don't fully understand it either perhaps not even a small bit. But from what I do understand it is impossible through natural selection to select for death unless that confers an advantage on the organism in question for replication.

asdasd

I think I already did tell you what I think in post #39, but I'll try again. Aging is the acummulation of damage which eventually causes frailty and pathology due to the fact that we have inadequate mechanisms for dealing with the damage thus we die from amongst other things aging. Seems pretty simple to me.

But wrong. If the accumulation of damage theory were true then all animals would decline at the same rate, an all animals would decline from birth. I have now posted that rebuttal three times.

The suggestion that genetic evolution has made some kind of concious decision to build in a gene for rotting the body

Nobody says that evolution is conscious of anything.

in my opinion suggests that you don't fully understand evolution and if I'm completely honest I don't fully understand it either perhaps not even a small bit

You dont. heres the thing about evolution. It selects for genes that are advantageous up until the animal's ability to procreate is ended. All that the gene needs to do to survie is get a copy to the next generation. Then we can age, and die.

Prof.Badass

asdasd wrote: »

But wrong. If the accumulation of damage theory were true then all animals would decline at the same rate, an all animals would decline from birth. I have now posted that rebuttal three times.

Damage starts occuring before we are even born. However, animals that begin to show this ageing before they reach reproducing age will be heavily selected against. Therefore most animals will age slow enough to still look undamaged when they reach reproducing age. However this damage will continue occuring at the same rate and the animal will begin to eventually show signs of decline.

Different animals age at different rates due to more/less selective pressure on ageing defenses.

asdasd

Therefore most animals will age slow enough to still look undamaged when they reach reproducing age. However this damage will continue occuring at the same rate and the animal will begin to eventually show signs of decline.

i really find arguments like this nonsensical. Sure the word are there, and it is gramatical, but like a medieval text there is no there there.

What do you mean by

this damage will continue occuring at the same rate

If that means all animals are "damaged" by free radicals ( or whatever) at the same rate, then the fact that some of them handle it better means sensence is genetic.

Different animals age at different rates due to more/less selective pressure on ageing

Are you trying to refute my point about senesecence being built-in with that statement? If so read it again...

Free radicals are only a "cause" of aging because our body stops its defence against them. The damage correlates with aging, but the cause is built in senesence.