Reproductive strategies in female postgenerative life
In: Fisher, M. L., Garcia , J. R., Chang, R. S. (Eds.): Evolution's empress: Darwinian perspectives on the nature of women, 243–259
New York, Oxford University Press (2013)
Women’s postgenerative longevity represents one of the major puzzles in Darwinian theory. This chapter argues that cooperative breeding fits well as an evolutionary explanation for increased lifespan. It covers the ways through which mothers who live beyond their generative career are still able to increase their reproductive success, due to the behavioral diversity of grandmothers. First, it briefly reviews the available empirical data on fitness-relevant behavioral traits, which have been described for postmenopausal mothers. Second, it is found that grandmaternal strategies are conditional and therefore dependent on various factors. Among these are differences in genetic relatedness between grandmothers and their daughters or their daughters-in-law. Moreover, socioeconomic conditions might also contribute to the partly contradictory effects, which have been reported from various populations for maternal and paternal grandmothers as well.