"It’s like a kid growing up. He’s given a genotype at birth. But how he ends
up... Well, if he gets enough food to eat, he develops one way. He’s healthy.
He’s got muscles that support him. If he doesn’t get enough food, his limbs get
thin, his belly bloats. Both bodies are consistent within the range of
possibilities dictated by his genotype. But only the genotype’s interaction with
the environment can fully determine what the phenotype will be."