Arguments Against Antagonistic Pleiotropy Hypothesis

 

Type: Non adaptive hypothesis

Definition: “Senescence” is caused by pleiotropic genes with beneficial effects at early ages and deleterious effects at later ages.

Proposers: Williams 1957; Rose 1991.

Theoretical arguments against the hypothesis:
This hypothesis implicitly assumes - without any proof - that the hypothesized genes have no alternative gene with analogous good effects at early ages and no deleterious effect at later ages.

Empirical Evidence:
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
4) There is no documentation about aging-causing antagonistic pleiotropic genes in species that show the aging phenomenon [Ricklefs 1998]

Conclusion: Antagonistic Pleiotropy Hypothesis is strongly contradicted by theoretical arguments and by empirical evidence and is not a plausible hypothesis for aging.

References:
- Ricklefs, R.E. (1998) Evolutionary Theories of Aging: Confirmation of a Fundamental Prediction, with Implications for the Genetic Basis and Evolution of Life Span. Am. Nat. 152, 24-44. [PubMed] [Google Scholar]
- Rose M.R. (1991) Evolutionary biology of aging. Oxford University Press, New York. [Google Scholar]
- Williams G.C. (1957) Pleiotropy, natural selection and the evolution of senescence. Evolution 11, 398-411. [Google Scholar]

www.Programmed-Aging.org

Sponsored by Azinet LLC © 12/2009