Biology Regents Practice Exam

How do mutations contribute to evolution?

1. They reduce genetic diversity

2. They provide new traits for selection

3. They eliminate species

4. They stabilize populations

The correct answer is: They provide new traits for selection

Mutations are changes in the DNA sequence that can introduce new genetic variations within a population. These variations are essential for evolution because they can lead to the development of new traits that may confer advantages or disadvantages in a particular environment. When these new traits arise, natural selection can act on them; advantageous mutations may become more common in the population over time, leading to evolutionary change. For example, if a mutation results in a trait that allows an organism to better survive and reproduce in its environment, that trait is likely to be passed on to future generations. This process contributes to the overall adaptive evolution of a species, as the population may gradually evolve in response to changing environmental conditions and selective pressures. Thus, mutations play a crucial role in providing the raw material for evolution by generating the diversity that selection can act upon.