According to theory promulgated by evolutionary biology, the main reason for our reality is to perpetually ensure the existence of the next generation of our species. Thus, most of us are “wired” to be very healthy in order to procreate. After accomplishing this, in the evolutionary biology perspective, there is not a valid reason for us to remain intact, or even alive, e.g. beyond about 50 years. But although our “Natural Selection Insurance Policy” expires with advancing adult age, we remain alive because our environment has been protected by better hygiene, better nutrition, better healthcare that keep us alive well beyond our evolutionary life expectancy. (Adapted from Judy Campisi, personal communication)