nostr:npub17aqgyjm4p8z9r42mpwkt45qln7sh4hr65z2gzwahgjtchr7vmsms8g3dh0 nostr:npub1urqxmm0ezqzlw7nkhe0jl44pnmz4u5ddjau8rf7fkwjmz08f6aeqwneh67 Vertebrate animals have ageing. It's less obvious that invertebrates, eukaryotes, and non-animals (eg. plants and fungi and archaea) have baked-in senescence: indeed, many don't. (I speculate wildly that senescence is a side-effect of cellular differentiation into specialized tissues including the immune system, and didn't get selected out because it didn't impair reproductive fitness. Cf. naked mole rats—mammals with extreme longevity and cancer-resistance.)