Why are not all types of living beings the same size?

Question

for example elephant isn’t the same size as a sheep

In: 0

Answer 1

After hundreds of thousands of reproductive generations, in one biome, smallish size and wool coats led what became sheep to consistently not die before reproducing, whereas in another biome, being massive and stompy, and having tusks and a trunk led what eventually became elephants to consistently not die before reproducing.