4 ms·

Not sure if aging is related to growing forever. Our ears never stop growing but they don't live forever :P It's more likely that those animals descended from

Not sure if aging is related to growing forever. Our ears never stop growing but they don't live forever :P It's more likely that those animals descended from an ancestor that didn't 'age' in the conventional sense _and_ had slow, unrestricted growth. Those two traits are not necessarily related. Not sure if I agree with the 'specialized' moniker. All creatures are specialized to their ecological niche. Humans are kind of an exception. What may have been selected for is fast and adaptable organisms. Why bother with 'aging' if you can tolerate damage over time, in exchange for more efficient organisms in the short term? You only need to repair enough to ensure the organism will reproduce (and maybe help care for the offspring for a while). Humans are actually pretty good in that aspect compared to many animals. Probably because it takes a while before we are able to reproduce.

celrod 4y ago
I think slow aging/longevity are "hard". You need excellent repair mechanisms, and for nothing to go wrong for a very long time. Random mutations can easily cause problems/chop some time off your lifespan. The question is, do individuals within the species benefit from longer life spans? To what extant are age related problems contributors to the deaths of individuals within a species? I would guess that a higher percentage of turtles at a reproductive age die of age related disease than reproductively mature rats. I would guess that turtles are much better at withstanding the passage of time, because time is a much more significant killer of turtles. Similarly, flying birds and bats tend to live longer than mammals of similar body mass, probably because predation is a less significant contributor to their mortality (and thus issues such as age, relatively more significant). Primates may be an exception, but they're also rather good at avoiding predators.

celrod 4y ago

I think slow aging/longevity are "hard". You need excellent repair mechanisms, and for nothing to go wrong for a very long time. Random mutations can easily cause problems/chop some time off your lifespan. The question is, do individuals within the species benefit from longer life spans? To what extant are age related problems contributors to the deaths of individuals within a species? I would guess that a higher percentage of turtles at a reproductive age die of age related disease than reproductively mature rats. I would guess that turtles are much better at withstanding the passage of time, because time is a much more significant killer of turtles. Similarly, flying birds and bats tend to live longer than mammals of similar body mass, probably because predation is a less significant contributor to their mortality (and thus issues such as age, relatively more significant). Primates may be an exception, but they're also rather good at avoiding predators.