Type: Non adaptive hypothesis
Definition: “Aging” is due to the effects of harmful mutations, accumulated over evolutionary time, which manifest themselves at older ages when, in the wild, survivors are very few or absent and, consequently, selective forces are too weak to eliminate them
Proposers: Medawar 1952; Hamilton 1966; Edney & Gill 1968; Mueller 1987; Partridge & Barton 1993.
Theoretical arguments against the hypothesis:
Simple theoretical arguments contradict strongly Mutation Accumulation Hypothesis.
1) The existence of animals with negligible senescence is against the hypothesis.
2) The inverse correlation observed in the wild between extrinsic mortality rate and proportion of deaths due to intrinsic mortality is against the hypothesis.
3) The existence of mechanisms genetically determined and regulated limiting cell turnover and, therefore, lifespan is against the hypothesis.
Conclusion: Mutation Accumulation Hypothesis is strongly contradicted by theoretical arguments and by empirical evidence and is not a plausible hypothesis for aging.
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