What is the role of mutations in evolution?

What is the role of mutations in evolution?

• A. Mutations introduce new genetic variation on which natural selection can act.
• B. Mutations always reduce fitness.
• C. Only sexual reproduction creates mutations.
• D. Mutations are reversible on all occasions.

Answer: (A)

Mutations introduce new genetic variation on which natural selection can act. Mutations are changes in DNA that create new alleles, providing the raw material for evolution. Natural selection can only favor traits that differ genetically and are heritable, so the introduction of new variants through mutation allows populations to adapt to changing environments over time. Mutations do not always reduce fitness; many are neutral or even beneficial in certain contexts, while most are sometimes harmful or have no effect at all. Also, mutations can arise in any organism, not just through sexual reproduction, since they occur during DNA replication or due to external factors. And reversibility is not guaranteed—back mutations are possible but not universal, and many mutations persist or are offset by other genetic changes. So the essential role is that mutations generate new genetic variation that natural selection can act upon, driving evolutionary change.

Mutations introduce new genetic variation on which natural selection can act. Mutations are changes in DNA that create new alleles, providing the raw material for evolution. Natural selection can only favor traits that differ genetically and are heritable, so the introduction of new variants through mutation allows populations to adapt to changing environments over time.

Mutations do not always reduce fitness; many are neutral or even beneficial in certain contexts, while most are sometimes harmful or have no effect at all. Also, mutations can arise in any organism, not just through sexual reproduction, since they occur during DNA replication or due to external factors. And reversibility is not guaranteed—back mutations are possible but not universal, and many mutations persist or are offset by other genetic changes.

So the essential role is that mutations generate new genetic variation that natural selection can act upon, driving evolutionary change.