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We age because we grow

delete2009-02-25
delete27
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H
Hillard Kaplan *
A
Arthur J. Robson
DOI:10.1098/rspb.2008.1831delete
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Abstract

Abstract

En 中文
Why do we age? Since ageing is a near-universal feature of complex organisms, a convincing theory must provide a robust evolutionary explanation for its ubiquity. This theory should be compatible with the physiological evidence that ageing is largely due to deterioration, which is, in principle, reversible through repair. Moreover, this theory should also explain why natural selection has favoured organisms that first improve with age (mortality rates decrease) and then deteriorate with age (mortality rates rise). We present a candidate for such a theory of life history, applied initially to a species with determinate growth. The model features both the quantity and the quality of somatic capital, where it is optimal to initially build up quantity, but to allow quality to deteriorate. The main theoretical result of the paper is that a life history where mortality decreases early in life and then increases late in life is evolutionarily optimal. In order to apply the model to humans, in particular, we include a budget constraint to allow intergenerational transfers. The resultant theory then accounts for all our basic demographic characteristics, including menopause with extended survival after reproduction has ceased.
Keywords:
aging
evolution
hunter-gatherers
life history
disposable soma
somatic capital
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Journal

P
Proceedings of the Royal Society B-Biological Sciences
IF:
3.5
Papers:
1.5W
Citations:
5.7W

Organization

S
Simon Fraser University
Scholars:
1.0W
Papers: 1.0W
Citations: 1.4W
U
university of new mexico
Scholars:
1.6W
Papers: 1.3W
Citations: 25