New species develop naturally through the process of natural selection . Due to natural selection, organisms with traits that better enable them to adapt to their environment will tend to survive and reproduce in greater numbers. Natural selection causes beneficial heritable traits to become more common in a population and unfavorable heritable traits to become less common. For example, a giraffe’s neck is beneficial because it allows the giraffe to reach leaves high in trees. Natural selection caused this beneficial trait to become more common than short necks.
There are two types of mice living in the rocky Black Mountain region: a brown mouse and a black mouse. The Black Mountain region is also home to the hawk, which preys on mice. In the Black Mountain region, the majority of the rocks are black.  This makes it easy for the hawk to see the brown mice, but hard for the hawk to see the black mice.
Which type of mouse is more likely to survive, the black mouse or the brown mouse?