Journal ArticleDOI
Evolution of senescence: late survival sacrificed for reproduction.
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TLDR
The antagonistic pleiotropy theory proposes that certain alleles that are favoured because of beneficial early effects also have deleterious later effects, and the disposable soma theory suggests that because of the competing demands of reproduction less effort is invested in the maintenance of somatic tissues than is necessary for indefinite survival.Abstract:
In so far as it is associated with declining fertility and increasing mortality, senescence is directly detrimental to reproductive success. Natural selection should therefore act in the direction of postponing or eliminating senescence from the life history. The widespread occurrence of senescence is explained by observing that (i) the force of natural selection is generally weaker at late ages than at early ages, and (ii) the acquisition of greater longevity usually involves some cost. Two convergent theories are the ‘antagonistic pleiotropy’ theory, based in population genetics, and the ‘disposable soma’ theory, based in physiological ecology. The antagonistic pleiotropy theory proposes that certain alleles that are favoured because of beneficial early effects also have deleterious later effects. The disposable soma theory suggests that because of the competing demands of reproduction less effort is invested in the maintenance of somatic tissues than is necessary for indefinite survival.read more
Citations
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Journal ArticleDOI
The Free Radical Theory of Aging Matures
Kenneth B. Beckman,Bruce N. Ames +1 more
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Understanding the odd science of aging
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A mutant Drosophila insulin receptor homolog that extends life-span and impairs neuroendocrine function.
TL;DR: It is concluded that juvenile hormone deficiency, which results from InR signal pathway mutation, is sufficient to extend life-span, and that in flies, insulin-like ligands nonautonomously mediate aging through retardation of growth or activation of specific endocrine tissue.
Journal ArticleDOI
Grandmothering, menopause, and the evolution of human life histories
TL;DR: This hypothesis also accounts for the authors' late maturity, small size at weaning, and high fertility, and has implications for past human habitat choice and social organization and for ideas about the importance of extended learning and paternal provisioning in human evolution.
References
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Book
Free radicals in biology and medicine
TL;DR: 1. Oxygen is a toxic gas - an introduction to oxygen toxicity and reactive species, and the chemistry of free radicals and related 'reactive species'
Journal ArticleDOI
Pleiotropy, natural selection, and the evolution of senescence
TL;DR: August Weismann's theory is subject to a number of criticisms, the most forceful of which are: 1) The fallacy of identifying senescence with mechanical wear, 2) the extreme rarity, in natural populations, of individuals that would be old enough to die of the postulated death-mechanism, 3) the failure of several decades of gerontological research to uncover any deathmechanisms, and 4) the difficulties involved in visualizing how such a feature could be produced
Journal Article
Pleiotropy, Natural Selection, and the Evolution of Senescence
TL;DR: A new individual entering a population may be said to have a reproductive probability distribution as discussed by the authors, where the reproductive probability is zero from zygote to reproductive maturity, i.e., the individual will have no reproductive capability from birth to maturity.