Final answer:
Mutations are not always bad. Some mutations can be beneficial, some are neutral, and some are harmful.
Step-by-step explanation:
Mutations are not always bad. Some mutations can be beneficial, some are neutral, and some are harmful. Beneficial mutations lead to changes that improve an individual's survival and/or chances of reproduction. Harmful mutations, on the other hand, can cause genetic disorders or cancer.
For example, the mutation that confers resistance to insecticide in mosquitoes is beneficial as it improves their survival. On the other hand, harmful mutations can cause genetic disorders like PKU.
In summary, mutations are essential for evolution as they increase genetic variation, but while some mutations are beneficial, the majority are harmful.