..............................biological decay does not lead to death., biological decay happens AFTER THE DEATH OF THE SPECIES., and that you are exploring in your folder as "Ageing Process of a species"., May be you are confused with those two words or wrongly worded Ageing Process as
biological decay.....................
well correct me if I am wrong in my view on those points...
decay/degeneration/damage - the unavoidable side effect of being alive according to some scientists.
disembowelment - the perpetual punishment for disbelief according to some religionists.
either option isn't particulary attractive so perhaps it's better not to think about it too much? children/adults are inevitably indoctrinated into some world view so it may be futile to worry about the "truth" in the grand scheme of things.
well let me move that part of the posts on ageing here dear crumble....