Costs and Consequences of Reproduction

Abstract

The life history of women is characterized by several unusual patterns: women have a relatively late age at maturity compared to other primates, they produce offspring at short inter-birth intervals, and typically have many dependent offspring of varying ages to care for simultaneously. Women then lose their potential to bear children at menopause but can live a few decades afterwards. Such a reproductive strategy involves several trade-offs and costs of reproduction to future success that have to be optimized across the entire lifespan. This chapter summarizes evidence from humans on the costs of reproduction. First, I discuss the short-and long-term effects of investment in reproduction on the survival patterns of individuals. Second, I address how current reproductive investment affects the ability to invest in future reproductive events. Third, I review the evidence for such costs of reproduction and trade-offs changing with the age of the individual and across different environments. Trade-offs are predicted to be most severe among the very young and senescing females, and when resources are limited. Finally, I investigate the heritable genetic basis for individual differences in the consequences of reproduction, and how heritabilities and genetic trade-offs between traits vary with age and across environmental conditions.