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Indeed. From a biological standpoint, it's important to realize that an indefinite lifespan, as a life history trait [1], does not confer evolutionary fitness.

Indeed. From a biological standpoint, it's important to realize that an indefinite lifespan, as a life history trait [1], does not confer evolutionary fitness. The fact is that organisms do not appear to evolve to a maximal lifespan — they evolve to an optimal lifespan. Humans are already considered to be K-selected [2], and increasing lifespan appears to necessarily decrease fitness in other areas, as has been seen in worms [3] and flies [4] (e.g. reproductive fitness decreases and age of maturity increases, when lifespan increases). More importantly, "near-infinite" lifespans reduce the efficacy of natural selection — longer-living organisms evolve at a slower rate. While, perhaps, unappealing, the culling of species members well past reproductive age is necessary to allow for more resources and potential for competition and selection in their offspring. And humans are certainly still undergoing natural selection in many arenas; just look at sickle cell trait [5] or or CCR5-Δ32 [6]. Death is a feature, not a bug. [1] https://en.wikipedia.org/wiki/Life_history_theory https://en.wikipedia.org/wiki/Life_history_theory [2] https://en.wikipedia.org/wiki/R/K_selection_theory https://en.wikipedia.org/wiki/R/K_selection_theory [3] http://www.ncbi.nlm.nih.gov/pubmed/8608934 http://www.ncbi.nlm.nih.gov/pubmed/8608934 [4] http://www.ncbi.nlm.nih.gov/pubmed/25601460 http://www.ncbi.nlm.nih.gov/pubmed/25601460 [5] http://www.ncbi.nlm.nih.gov/pubmed/11965279 http://www.ncbi.nlm.nih.gov/pubmed/11965279 [6] https://www.ncbi.nlm.nih.gov/pubmed/8791590 https://www.ncbi.nlm.nih.gov/pubmed/8791590

reasonattlm 11y ago
These are all arguments that apply to the house you live in, the blankets on your bed, the medicine you use. You are absolutely fine with all of those - you don't live in a cave, shun treatment for infectious disease, and wear furs. In fact I would go so far as to say that you probably think that modern technology is a good thing, and you are better off for it. Yet that already greatly manipulates your proposed optimal condition for the human species. So why does treating aging as a medical condition bring out this view? This seems like a very selective appeal to nature.
- jashephe 11y ago
  It may not have been expressed the most clearly, but the intention was not quite as you describe. Shelter, clothing, and modern medicine all confer enhanced fitness — I was attempting to suggest that increased lifespan does not.

reasonattlm 11y ago

These are all arguments that apply to the house you live in, the blankets on your bed, the medicine you use. You are absolutely fine with all of those - you don't live in a cave, shun treatment for infectious disease, and wear furs. In fact I would go so far as to say that you probably think that modern technology is a good thing, and you are better off for it. Yet that already greatly manipulates your proposed optimal condition for the human species. So why does treating aging as a medical condition bring out this view? This seems like a very selective appeal to nature.

jashephe 11y ago
It may not have been expressed the most clearly, but the intention was not quite as you describe. Shelter, clothing, and modern medicine all confer enhanced fitness — I was attempting to suggest that increased lifespan does not.