"According to the disposable soma theory, a cost for reproduction could exist in human beings and other species and, thus, longevity could decrease when women have a higher number of children. The purpose of this article is to review the evidence in populations living or not living under natural fertility conditions, i.e. when fertility is near its biological maximum. The results indicate that in natural fertility conditions longevity does not decrease when the number of children increases but, in modern populations, mortality could slightly increase when women have more than 5 children. Complete data for these modern cohorts will tell us, one day, whether these results are still observed when the variable of interest is longevity and not only mortality." The disposable soma theory of aging, arising from evolutionary considerations, has moved through a number of interations to its present form. It is not highly regarded in comparison to other theories, largely because of this sort of evidence. The model of the body as a self-repairing machine subject to an accumulation of characteristic types of damage it cannot repair far better fits the observed facts.

View the Article Under Discussion: http://pmid.us/17532269
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