Longevity and the costs of reproduction in a historical human population

It has been argued that the priority that natural selection places on repro duction negatively affects other processes such as longevity and the proble m posed by this trade-off underlies the disposable soma theory for the evol ution of human ageing. Here we examine the relationship between reproductio n and longevity in a historical human population (the Krummhorn, north-west Germany 1720-1870). In our initial analyses, we found no support for the h ypothesized negative effects of reproduction on longevity: married women wh o remained childless lived no longer than women who reproduced and women wh o had few children lived no longer than women who had many children. Howeve r, more detailed analyses in relation to socio-economic class revealed that the extent to which reproduction has an effect on longevity is a function of the level of economic deprivation. We found that, when possible sources of confound were controlled for (e.g. duration of marriage and amount of ti me spent in fecund marriage), there is an increasingly strong relationship between longevity and reproduction with increasing poverty.