Answer:Traits are determined by genes, and also they are determined by the interaction with the environment with genes. And remember that genes are the messages in our DNA that define individual characteristics. So the trait is the manifestation of the product of a gene that is coded for by the DNA.
Explanation:
Species selection. Species selection is the process by which intrinsic biological characteristics in organisms change depending on the type of environment they're interacting with. In this case, the subsequent generations of the fly lost the ability to fly because their environment didn't require them to use wings for survival, hence they stopped growing them and subsequently lost the ability to fly.