Human longevity and early reproduction in pre-industrial Sami populations

Authors


Samuli Helle, Section of Ecology, Department of Biology, University of Turku, FIN-20014 Turku, Finland. Tel.: +358 2333 6559; fax: +358 2333 6550; e-mail: samuli.helle@utu.fi

Abstract

Senescence is predicted to be associated with the intensity and timing of reproduction at an earlier age. Here, we examine the phenotypic association between reproduction and post-reproductive survival in three pre-industrial human populations that lived in Northern Scandinavia during 1640–1870. In both sexes longevity was independent of the total number of born or adult children, whereas early reproduction was negatively associated with the longevity of females and males. Our results thus do not support the view that reproductive investment as such has a negative impact on longevity, but suggest that survival costs are associated with the scheduling of reproduction. We discuss, however, an alternative point of view suggesting that less intense selection for early reproduction, extended parental care, and social structure allowing kin selection through the effects of close relatives are factors that have selected for the long post-reproductive life span in humans.

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