I can't find the study now, but birth rate goes down as resource use goes up, where human females consume more resources than elephant females and have lower fertility rates. This follows from D'Arcy Thompson's studies on growth and form, where there are certain universal physical constraints regardless of species variables.
Plus, evolution is substrate neutral, it's just how information manages to reproduce itself. Whether it's the genes of mitochondria and other single celled organisms coming together to form communities based on trading DNA that then enclosed all of them and became multicellular organisms, to certain multicellular organisms forming communities that trade memes and become enclosed in even larger super-organisms.
The super-organisms can still get cancer, which is also substrate neutral and a natural result of evolution.
Evolution is just what can survive and reproduce does, and what can't doesn't.
It doesn't mean anything is supposed to survive.
Plus, evolution is substrate neutral, it's just how information manages to reproduce itself. Whether it's the genes of mitochondria and other single celled organisms coming together to form communities based on trading DNA that then enclosed all of them and became multicellular organisms, to certain multicellular organisms forming communities that trade memes and become enclosed in even larger super-organisms.
The super-organisms can still get cancer, which is also substrate neutral and a natural result of evolution.
Evolution is just what can survive and reproduce does, and what can't doesn't.
It doesn't mean anything is supposed to survive.