I don't know that we have evidence that survival instinct goes away after reproduction. It's still valuable to our species to survive after reproduction in order to protect and nurture offspring, for example.
There's no evolutionary reason that survival instinct would turn off after a certain age.
> There's no evolutionary reason that survival instinct would turn off after a certain age
Umm, without wishing to get too clinical or morbid, it's clear that once your offspring have reached adulthood there will always come a point beyond which you rely on them more than they rely on you, right?
There's no evolutionary reason that survival instinct would turn off after a certain age.