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 ca

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.