Among the non-mammalian vertebrates, the cloaca is an anatomical structure that function as a shared pathway for the digestive, excretory, and reproductive systems. Cloaca in vertebrates, common chamber and outlet into which the intestinal, urinary, and genital tracts open. It is present in amphibians, reptiles, birds, elasmobranch fishes, and monotremes. Cloaca is not present in placental mammals or in most bony fish.
Hi
Answer: Its origin is not sunlight
I hope that's help !
Answer:
If I am correct it is when the weaker individuals or mutated individuals are killed of by other predators or by nature. Because they cannot survive this is natural selection because they are killed of by nature. Then if they are weak their species will go extinct, thus they are naturally selected to die and only the strong species remain.