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The somatic mutation theory of ageing states that accumulation of mutations in somatic cells is the primary cause of aging. A comparison of somatic mutation rate across several mammal species found that the total number of accumulated mutations at the end of lifespan was roughly equal across a broad range of lifespans. [16]
The mutation accumulation theory of aging was first proposed by Peter Medawar in 1952 as an evolutionary explanation for biological aging and the associated decline in fitness that accompanies it. [1] Medawar used the term 'senescence' to refer to this process.
Somatic mutations accumulate within an organism's cells as it ages and with each round of cell division; the role of somatic mutations in the development of cancer is well established, and the accumulation of somatic mutations is implicated in the biology of aging. [4]
The disposable soma theory of aging posits that there is a trade-off in resource allocation between somatic maintenance and reproductive investment.Too low an investment in self-repair would be evolutionarily unsound, as the organism would likely die before reproductive age.
A related theory is that mutation, as distinct from DNA damage, is the primary cause of aging. A comparison of somatic mutation rate across several mammal species found that the total number of accumulated mutations at the end of lifespan was roughly equal across a broad range of lifespans. [49]
Somatic hypermutation (or SHM) is a cellular mechanism by which the immune system adapts to the new foreign elements that confront it (e.g. microbes).A major component of the process of affinity maturation, SHM diversifies B cell receptors used to recognize foreign elements and allows the immune system to adapt its response to new threats during the lifetime of an organism. [1]
Aging theories based on group selection; Antagonistic pleiotropy hypothesis; C. ... Genetic mutation theory of aging; I. Immune system theory of aging;
Aging theories based on group selection; Antagonistic pleiotropy hypothesis; C. ... Genetic mutation theory of aging; I. Immune system theory of aging;