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So... One individual out of 28 is known to be 400 years old. There is a subadult population bulge. Any way of estimating natural life spans from this? Could be
by dalbasal 6y ago
So...
One individual out of 28 is known to be 400 years old. There is a subadult population bulge. Any way of estimating natural life spans from this? Could be some very, very old sharks out there. I wonder how big the 400yr old one is, relative to max known size.
- rahimiali 6y agothe two other useful observations are that they seem not get bigger than 5m, and that they grow by 1cm per year.
- mr_toad 6y agoYou’d need to know the probability of death as a function of chronological age. If the probability is constant, you can model the lifespan as an exponential decay - there is no real upper limit, but the population of older individuals is very small. For most animals the probability increases as they age, and becomes very high towards the end of their life, but this is not the case for all animals. https://en.wikipedia.org/wiki/Negligible_senescence https://en.wikipedia.org/wiki/Negligible_senescence
- dalbasal 6y agoThanks for the breakdown. "(probability) becomes very high towards the end of their life." This is, ultimately, what we want to know. At what age do they start to die of old age? Oldest living vertebrate is interesting, but I think it's mostly interesting because of what it says about the species? Is it possible that a large vertebrate doesn't have an old age point, where probability of death is very high?