the actual CORRECT answer is change.
So,
The environment needs to [change] in order for natural selection to occur.
Don't worry i took the test trust me!
Answer:
By the process of cellular differentiation which consists of physical and functional changes of the cell used by processes at the genetic level. The expression of these in each type of cell is different. That is to say that the type of cell follows at a time of development there is differential activation of some genes and repression of others
It is the last choice because their similar bone structures suggest they once had a common ancestor, which is why they are all mammals.
