Final answer:
No, individuals within populations do not change over their lifetime due to natural selection. Natural selection acts on populations, not individuals.
Step-by-step explanation:
No, individuals within populations do not change over their lifetime due to natural selection acting upon their individual fitnesses. Evolution is the change in genetic composition of a population over time, resulting from differential reproduction of individuals with certain alleles. While individuals may change over their lifetime through development, this is programmed by their genes and their environment. Natural selection acts on populations, not on individuals, and it selects for individuals with greater contributions to the gene pool of the next generation, known as evolutionary fitness.