Changes with Age. In most cases, a person's normal respiratory rate will change with age; younger adults, children, and babies will typically have faster respiratory rates, because as people age, their breathing usually slows down.
Modic changes are pathological changes in the bones of the spine, the vertebrae. These changes are situated in both the body of the vertebrae and in the end plate of the neighboring disc.
Changes within a gene pool occurring from generation to generation is called microevolution. Allele frequencies in a population may change due to gene flow, genetic drift, natural selection and mutation. These are referred to as the four fundamental forces of evolution. Note that only mutation can create new genetic variation.