A1 Vertaisarvioitu alkuperäisartikkeli tieteellisessä lehdessä
Are reproductive and somatic senescence coupled in humans? Late, but not early, reproduction correlated with longevity in historical Sami women
Tekijät: Helle S, Lummaa V, Jokela J
Kustantaja: ROYAL SOC
Julkaisuvuosi: 2005
Lehti:: Proceedings of the Royal Society B: Biological Sciences
Tietokannassa oleva lehden nimi: PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES
Lehden akronyymi: P ROY SOC B-BIOL SCI
Vuosikerta: 272
Numero: 1558
Aloitussivu: 29
Lopetussivu: 37
Sivujen määrä: 9
ISSN: 0962-8452
DOI: https://doi.org/10.1098/rspb.2004.2944
Tiivistelmä
Evolutionary theory of senescence emphasizes the importance of intense selection on early reproduction owing to the declining force of natural selection with age that constrains lifespan. In humans, recent studies have, however, suggested that late-life mortality might be more closely related to late rather than early reproduction, although the role of late reproduction on fitness remains unclear. We examined the association between early and late reproduction with longevity in historical post-reproductive Sami women. We also estimated the strength of natural selection on early and late reproduction using path analysis, and the effect of reproductive timing on offspring survival to adulthood and maternal risk of dying at childbirth. We found that natural selection favoured both earlier start and later cessation of reproduction, and higher total fecundity. Maternal age at childbirth was not related to offspring or maternal survival. Interestingly, females who produced their last offspring at advanced age also lived longest, while age at first reproduction and total fecundity were unrelated to female longevity. Our results thus suggest that reproductive and somatic senescence may have been coupled in these human populations, and that selection could have favoured late reproduction. We discuss alternative hypotheses for the mechanisms which might have promoted the association between late reproduction and longevity.
Evolutionary theory of senescence emphasizes the importance of intense selection on early reproduction owing to the declining force of natural selection with age that constrains lifespan. In humans, recent studies have, however, suggested that late-life mortality might be more closely related to late rather than early reproduction, although the role of late reproduction on fitness remains unclear. We examined the association between early and late reproduction with longevity in historical post-reproductive Sami women. We also estimated the strength of natural selection on early and late reproduction using path analysis, and the effect of reproductive timing on offspring survival to adulthood and maternal risk of dying at childbirth. We found that natural selection favoured both earlier start and later cessation of reproduction, and higher total fecundity. Maternal age at childbirth was not related to offspring or maternal survival. Interestingly, females who produced their last offspring at advanced age also lived longest, while age at first reproduction and total fecundity were unrelated to female longevity. Our results thus suggest that reproductive and somatic senescence may have been coupled in these human populations, and that selection could have favoured late reproduction. We discuss alternative hypotheses for the mechanisms which might have promoted the association between late reproduction and longevity.
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