Describe how genetic variation is introduced into a population through both mutation and sexual reproduction

Mutation is the ultimate source of all new genetic variation. It involves random changes in the DNA sequence, which can create new alleles (different versions of a gene) that were not previously present in the population. These new alleles can then be passed on to offspring.

Sexual reproduction introduces genetic variation by combining existing alleles in new ways. During meiosis, independent assortment of chromosomes and crossing over between homologous chromosomes create unique combinations of alleles in gametes. When these gametes fuse during random fertilization, they produce offspring with a novel genetic makeup, different from either parent.