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Why are we genetically programmed to die?

  1. Mar 4, 2008 #1
    Our body is instructed to make our Immune system weaker at puberty....then, it is instructed to slowly poison our body at the age of 18....why? I know that as we live...we slowly damage ourself to death...but when we are kids, isn't our rate of recovery faster than the rate of damage? Then why does it slow down? I know how....it slows down b/c body only has a limited amount of untrained T-cells....but as body faces more and more diseases, it programs more and more T-cells....till it comes to a point where it cannot fight new diseases anymore.....

    This sounds pretty simple....why doesn't they just synthetically create t-cells(they already are taking dna out of one cell and implanting it into another) and insert it in our body?

  2. jcsd
  3. Mar 4, 2008 #2
  4. Mar 4, 2008 #3
    Can they make synthetic white blood cells that won't get rejected by the body?
  5. Mar 5, 2008 #4
    If we never died then assuming we have only a finite environment, eventually we'd be over populated, then presumably we'd die of natural causes. This however is hardly a very efficient way of disposing of people, and would probably cause environmental problems for other species, even worse if they too didn't die. Of course there is only a certain window of time where we can reproduce anyway, and after this our value in evolutionary terms is merely in bringing up our offspring and the knowledge we can pass on. So to be honest the simplest answer is, it just works better that way, there is greater diversity in our species because of it; it is an evolutionary fitter method of existing. Of course in things like plants where it's not so important to have a specific age, because once you reach a certain population then the system is fairly self contained and moderated by animals and other plants. Then you can have extraordinary long lived organisms. Also the longevity of an animal is related to mutation as well, the more diversity a population can exhibit, the greater its potential adaptability, this is weighed up against the other factors and all things considered the lifespan is generally that which promotes the greatest diversity and the greatest fitness. Something like that probably, not being an expert I'm not entirely sure.
  6. Mar 5, 2008 #5

    Andy Resnick

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    You present a lot of assertions without presenting any supporting evidence. For example, what do you mean by "...it is instructed to slowly poison our body at the age of 18.."?

    During embryogenesis, there is a lot of apoptosis- among other things, to ensure we have 5 fingers on each hand rather than a paddle. Does this support or refute your assertions?
  7. Mar 5, 2008 #6

    jim mcnamara

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    I imagine you are trying to describe mammalian aging. Not poisoning. Trying to work from today backwards over 270 million years to get an answer to an evolutionary change does not work. We cannot go back in time and see 'why' something happened.

    We can see the way things are today- homeothermic animals damage mitochondia and subsequently other tissues by burning food as fuel at a very high rate. This translates to the mitochondrial theory of aging. You can google for that. Poikilotheric animals live far longer, following this theory, simply because their metabolic rate is circa one order of magnitude slower than homeotherms.

    homeotherm=warm blooded
    poikiltherm=cold blooded
  8. Mar 7, 2008 #7

    I'm always impressed with your replies. You do a good job of steering clear of needless speculation.

    On this topic though, I'd appreciate a little from you. Does the mitochondrial theory of aging have good evidential support? What are it's logical implications (e.g. do high activity life styles accelerate cellular aging via boosting metabolic rates)???

    In any case, interesting stuff...
  9. Mar 7, 2008 #8
    There are many factors for the cause of aging.

    Anyone looking for a "silver bullet" cure is setting themselves up for a big disappointment.

    We are living beings programmed to grow old and die....just accept it and enjoy what life you have! :P
  10. Mar 7, 2008 #9
    There is no death gene. DNA over time becomes damaged. That's all there is folks. Stop the damage, live forever.
  11. Mar 7, 2008 #10

    jim mcnamara

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    There are several theories of aging - the mitchondrial damage theory is one.
    Yes, Bruce Ames et al (all good researchers) have published a series of papers on it.

    Now the bad part - I guess he thought enough of his work in this area to create a supplement. There are reports from several researchers that alpha lipoic acid in combination with acetyl-carnitine does have in vitro effects - reversing mitochondial oxidative damage. There are some in vivo studies as well.

    Anyway - the site that promotes the pill also does have good links to real peer reviewed research. Since I'm too lazy to compile myself separately:
    Last edited: Mar 7, 2008
  12. Mar 7, 2008 #11

    jim mcnamara

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    Greg - an awful lot of mortality derives from things other than "age" -
    pathogens, environmental problems - cancer is thought to be largely environmental for example, so are a lot of cardiovascular problems, trauma, violence, spousal retribution for years of your tweaking PF instead of taking her out - you name it.

    Nothing and nobody lives forever. Sorry.
  13. Mar 7, 2008 #12
    As Homer Simpson said, “I fall down stairs alot.”
  14. Mar 7, 2008 #13
    If anything, this is how I will go out! :tongue2:
  15. Mar 8, 2008 #14

    jim mcnamara

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    Speaking of tweaks I like the new first page - "atoms" are cool.
  16. Mar 8, 2008 #15
    Yeah - I hadn't noticed that. Noice.

    One little bit of critical feedback I'll make: I think the spacing gap at the top of quoted sections (divs?) is a bit too large, especially now that you've moved the background shading to the inner div and you're using that large quote image / character (which looks nice btw), a little CSS tweak could bring it down.
    Last edited: Mar 8, 2008
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