There’s isn’t anything doing selecting. A gene mutates and if it stays in the mating cycle enough times to become part of the species as a whole then it’s become “selected”. That includes things that aren’t good for adapting to an environment as well as things that are.
This makes me wonder, why are there no 100% albino species considering albinos can be found in every species and can only produce other albino offspring when paired with other albinos?
First, the vast majority of species depend on camouflage at least somewhat, since there are very few species that are neither predator nor prey. Also, albinism prevents your skin from properly protecting you from the sun. So even then, it is selected against. As other have pointed out though, caves don’t have either of these forces at play—the darkness makes visual camouflage irrelevant and there is no UV light. So there, as you predicted, most species are albino.
There’s isn’t anything doing selecting. A gene mutates and if it stays in the mating cycle enough times to become part of the species as a whole then it’s become “selected”. That includes things that aren’t good for adapting to an environment as well as things that are.
This makes me wonder, why are there no 100% albino species considering albinos can be found in every species and can only produce other albino offspring when paired with other albinos?
They get eaten
How does being albino automatically mean being eaten (assuming we rule out species that need camouflage)?
First, the vast majority of species depend on camouflage at least somewhat, since there are very few species that are neither predator nor prey. Also, albinism prevents your skin from properly protecting you from the sun. So even then, it is selected against. As other have pointed out though, caves don’t have either of these forces at play—the darkness makes visual camouflage irrelevant and there is no UV light. So there, as you predicted, most species are albino.