The most accurate statement about natural selection is:
Natural selection does not change the alleles an organism has.
Instead, natural selection acts on the existing genetic variation within a population. It favors certain traits that enhance survival and reproduction, leading to changes in the frequency of alleles in the population over time, but it does not change the alleles in an individual organism.
The other statements are not accurate:
- Natural selection can influence which genes are expressed or suppressed, but it does not "inactivate" genes in the sense of permanently altering the genetic code.
- While mutations can introduce new alleles into a population, natural selection operates on the effects of these mutations and other existing alleles rather than causing mutations itself.
- Natural selection does impact reproduction rates by favoring individuals with traits that enhance reproductive success.