Final answer:
DNA mutations in somatic cells acquired during adulthood do not contribute to the evolution of a population because they are not passed on to the next generation, unlike mutations in gamete-producing cells and other factors that increase genetic diversity.
Step-by-step explanation:
If variation of heritable traits is the basis of all evolution, the option that would NOT contribute to the evolution of a population is b) DNA mutations in somatic cells acquired during adulthood. Mutations in somatic cells do not get passed on to offspring because they are not present in the gametes (sperm or egg cells), which are the cells responsible for transmitting genetic information to the next generation. On the other hand, a maternally inherited allele, DNA mutations in gamete-producing cells, a new combination of alleles resulting from meiotic recombination, and migration that brings novel alleles into a population, all contribute to the genetic diversity of a population and therefore can drive evolution.