How can you tell that organisms are members of the same species?

Key points. According to the biological species concept, organisms belong to the same species if they can interbreed to produce viable, fertile offspring. Species are separated from one another by prezygotic and postzygotic barriers, which prevent mating or the production of viable, fertile offspring.

Explanation:

he is very short, and he can only reach halfway up on the elevator buttons. but on a rainy day, he has his umbrella with him, and he uses it to poke the button at the top.