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Oxygen[0] by Nick Lane makes a pretty compelling argument why this will not happen. With perfect health you can at best achieve ~120 years age. I think this pap

by rusanu 11y ago

Oxygen[0] by Nick Lane makes a pretty compelling argument why this will not happen. With perfect health you can at best achieve ~120 years age. I think this paper A unifying view of ageing and disease:the double-agent theory[2] covers some of the arguments in the book. To give a simplified view, the big obstacles are a) a technology capable of repairing damaged mythocondrial material in a living organism and b) a technology capable of repairing neural cells w/o replacing them (that is if you want to preserver 'you', not just your body). That is assuming that our current understanding of senescence[1] is even mildly accurate. [0] http://www.amazon.com/Oxygen-Molecule-World-Popular-Science/dp/0198607830 http://www.amazon.com/Oxygen-Molecule-World-Popular-Science/... [1] https://en.wikipedia.org/wiki/Senescence https://en.wikipedia.org/wiki/Senescence [2] http://www.nick-lane.net/double-agent%20theory.pdf http://www.nick-lane.net/double-agent%20theory.pdf

EGreg 11y ago
What do you define as "perfect health" when you are made up of cells that keep being regenerated? Some animals have biological immortality as far as we know. Most however enter senescence after reproduction, probably because evolution optimized for that. I think that if we sampled people's DNA at 15, and then used a retrovirus every few years to refresh the DNA in the cells, we would solve the biggest issue of random mutations piling up. But this is a long way away. Of course, there may be other processes that build up but a youthful immune system should be able to fight them relatively effectively. Even so, the chance of death would only be reduced from exponential-exponential to exponential, since the chances of someone living A to B and B to C are independent and therefore multiply.
adrianN 11y ago
I'm pretty sure that you can replace a significant number of my neurons without changing "me".
- rendezvouscp 11y ago
  That’s a great question that’s been pondered by philosophers for a while: https://en.wikipedia.org/wiki/Ship_of_Theseus https://en.wikipedia.org/wiki/Ship_of_Theseus Here’s a fun video talking about the same thing: https://www.youtube.com/watch?v=nQHBAdShgYI https://www.youtube.com/watch?v=nQHBAdShgYI
- rusanu 11y ago
  What makes you sure? Central nervous system neurons are incapable of regeneration[0], so is anybody's guess what would happen if they did get replaced. And, long term, "significant" has to be "all". [0] https://en.wikipedia.org/wiki/Neuroregeneration https://en.wikipedia.org/wiki/Neuroregeneration
  - adrianN 11y ago
    People can have rather serious strokes that kill large number of neurons without losing their sense of self. Sometimes we remove half the brain https://en.wikipedia.org/wiki/Hemispherectomy https://en.wikipedia.org/wiki/Hemispherectomy That gives me confidence that replacing neurons at a rate that counters natural aging does not significantly alter me.
- snowwrestler 11y ago
  To the contrary, "you" are constantly changing as your existing neurons reconfigure themselves. Replacing them would have at least the same effect.
erjjones 11y ago
From a Biblical perspective (if you believe that) it isn't possible. Genesis 6:3

by rusanu 11y ago

EGreg 11y ago

What do you define as "perfect health" when you are made up of cells that keep being regenerated? Some animals have biological immortality as far as we know. Most however enter senescence after reproduction, probably because evolution optimized for that. I think that if we sampled people's DNA at 15, and then used a retrovirus every few years to refresh the DNA in the cells, we would solve the biggest issue of random mutations piling up. But this is a long way away. Of course, there may be other processes that build up but a youthful immune system should be able to fight them relatively effectively. Even so, the chance of death would only be reduced from exponential-exponential to exponential, since the chances of someone living A to B and B to C are independent and therefore multiply.

adrianN 11y ago

I'm pretty sure that you can replace a significant number of my neurons without changing "me".

rendezvouscp 11y ago
That’s a great question that’s been pondered by philosophers for a while: https://en.wikipedia.org/wiki/Ship_of_Theseus https://en.wikipedia.org/wiki/Ship_of_Theseus Here’s a fun video talking about the same thing: https://www.youtube.com/watch?v=nQHBAdShgYI https://www.youtube.com/watch?v=nQHBAdShgYI
rusanu 11y ago
What makes you sure? Central nervous system neurons are incapable of regeneration[0], so is anybody's guess what would happen if they did get replaced. And, long term, "significant" has to be "all". [0] https://en.wikipedia.org/wiki/Neuroregeneration https://en.wikipedia.org/wiki/Neuroregeneration
- adrianN 11y ago
  People can have rather serious strokes that kill large number of neurons without losing their sense of self. Sometimes we remove half the brain https://en.wikipedia.org/wiki/Hemispherectomy https://en.wikipedia.org/wiki/Hemispherectomy That gives me confidence that replacing neurons at a rate that counters natural aging does not significantly alter me.
snowwrestler 11y ago
To the contrary, "you" are constantly changing as your existing neurons reconfigure themselves. Replacing them would have at least the same effect.

erjjones 11y ago

From a Biblical perspective (if you believe that) it isn't possible. Genesis 6:3