Theories of aging Flashcards
what is antagonistic pleiotropy theory?
pleiotropic genes or molecular processes, which may benefit early fitness components in the young, may carry harmful effects on late-life fitness. Because there is no pressure for natural selection to favor traits for improving late-life fitness, genes with deleterious effects confined to late life are less likely to undergo negative selection.
EX: cellular senescence - tumor suppression in the young
what is disposable soma theory
considers aging to be a tradeoff between an organism’s efforts to maintain nonreproductive aspects (soma) and the cost of its efforts to reproduce. In this sense, available energy is limited and must be allocated between reproductive activities and repair or maintenance. Finite resources are invested in reproduction rather than in repair of other cellular damage. Thus, damage accumulates in the soma because the body cannot repair all of it.
What is Homeostenosis theory
narrowing of reserve capacity that contributes to decreased ability to maintain functional homeostasis under stress
what is Mutation accumulation theory
random, detrimental mutations accumulate over time and manifest their effects only late in life.
