Answer: The answer is natural selection
Explanation:
Natural selection explains how certain desirable traits like;
- shape of the beaks of Darwin's finches: to help them feed more easily
- industrial melanism to raise a population of dark-coloured organisms to evolve from pre-existing light coloured ones in industrial areas where the surrondings are blackened with soot;
are favored over LESS DESIRABLE TRAITS, resulting in organisms that are most suited/adapted to thrive in an environment, which is evolutionary change
This is a positive mutation, because the offspring will survive longer to reproduce. Their offspring will then carry the same genes passing it off to their offspring. The other color mice that did not blend into its environment will soon be extinct, leaving only the mice that can blend in.