4 ms·

This sort of adaptivism has got to go. First of all, nothing is there for any reason; it just is. Evolution is an ad hoc process where things happen because the

This sort of adaptivism has got to go. First of all, nothing is there for any reason; it just is. Evolution is an ad hoc process where things happen because they need to, and they happen based on expediency. There are many facets of life that escape adaptive constraint - selection has a limited reach. This comment supposes that aging protects cells against cancer; I think this presumption is based on the antitumor properties of telomeres, which impose the 'Hayflick limit' on cellular division. It is presumed by humans that this mechanism may have some adaptive role in tumor suppression. However: this is not why it appeared (all eukaryotes have telomeres, even unicellular ones), so any antitumor properties are an ancillary benefit. It is incorrect to assume it impute reason to evolution. It seems highly likely that aging rests close to the border of selective influence, and it is highly presumptive to imagine it is governed by consequence.

deleted 10y ago
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lqdc13 10y ago
This is not a presumption I made. This is believed by many scientists. Telomeres are just part of the story. There are many other reasons[1,2,3]. The third link is not a paper so very readable. The cell has many ways to combat oncogenesis and when these protections fail, it tries to go into senescence (SIGTERM) or die(SIGKILL). Nanobots that would replace damaged cells with new non-cancerous ones are not yet here. [1] http://www.impactaging.com/papers/v2/n7/full/100178.html http://www.impactaging.com/papers/v2/n7/full/100178.html [2] http://www.nature.com/nrc/journal/v3/n1/full/nrc984.html http://www.nature.com/nrc/journal/v3/n1/full/nrc984.html [3] http://newscenter.lbl.gov/2008/12/02/cellular-senescence/ http://newscenter.lbl.gov/2008/12/02/cellular-senescence/
- astazangasta 10y ago
  I'm a cancer biologist, so I appreciate the relation to oncogenesis. But you said "It is there for (probably) many reasons". This is what I am contending; aging is simply there, because that is what happened. 'Reason' is a judgment we apply, and it's important to appreciate that much of what exists is not driven by anything we might call "reason". I do not believe that the collection of phenomenon we call "aging" is uniformly the product of adaptive consequence. Notably, we die in part because evolution simply doesn't care, or isn't able, to keep us alive indefinitely.

deleted 10y ago

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lqdc13 10y ago

This is not a presumption I made. This is believed by many scientists. Telomeres are just part of the story. There are many other reasons[1,2,3]. The third link is not a paper so very readable. The cell has many ways to combat oncogenesis and when these protections fail, it tries to go into senescence (SIGTERM) or die(SIGKILL). Nanobots that would replace damaged cells with new non-cancerous ones are not yet here. [1] http://www.impactaging.com/papers/v2/n7/full/100178.html http://www.impactaging.com/papers/v2/n7/full/100178.html [2] http://www.nature.com/nrc/journal/v3/n1/full/nrc984.html http://www.nature.com/nrc/journal/v3/n1/full/nrc984.html [3] http://newscenter.lbl.gov/2008/12/02/cellular-senescence/ http://newscenter.lbl.gov/2008/12/02/cellular-senescence/

astazangasta 10y ago
I'm a cancer biologist, so I appreciate the relation to oncogenesis. But you said "It is there for (probably) many reasons". This is what I am contending; aging is simply there, because that is what happened. 'Reason' is a judgment we apply, and it's important to appreciate that much of what exists is not driven by anything we might call "reason". I do not believe that the collection of phenomenon we call "aging" is uniformly the product of adaptive consequence. Notably, we die in part because evolution simply doesn't care, or isn't able, to keep us alive indefinitely.