Evolutionary Theories of Aging

All living organisms age, from those with a life span of only a couple of days, such as the mayfly, to those with a longevity of centuries, for example, the Arctic whale and certain varieties of carp. In most organisms including humans, phenotypic traits that correspond to the set of individual characteristics (e.g., body mass, physiological performance like immunological parameters) do not remain constant over the life course. For a given trait, the individual performance reaches a peak or a plateau generally between early and mid-adulthood and then declines. These patterns lead to changes that decrease the likelihood of having a child (reproductive senescence) and increase the likelihood of dying (actuarial senescence).

For a very long time, aging has been considered a process that escaped the ...