This chapter presents new research directions and hypotheses based on the evolutionary relationships between reproductive effort and contemporary health challenges in men. Drawing on life history, these hypotheses are grounded in the observation that human male reproductive strategies exhibit a much broader range of variability compared to other great apes. Specifically, human males are unique in that they exhibit the capacity to devote a significant amount of time and energy to offspring and mate care, often spending much more of their lives providing paternal investment compared to other primates and indeed many mammals. Men also exhibit the capability to negotiate and partition investment in offspring according to perceived paternity. The extraordinary range of human male reproductive options can be viewed as selection for neuroendocrine adjustments in response to shifting mortality challenges and extended life spans. We hypothesize that (1) investment in offspring and mates evolved in tandem with decreases in human male mortality and morbidity, (2) male fertility at older ages coevolved with an increased capacity to defend against degenerative diseases, (3) testosterone and other neuroendocrine mechanisms are primary targets of selection for the evolution of these traits, and (4) trade-offs between male health maintenance, variation in paternal investment, and male reproductive strategies are contingent on energetic constraints. Drawing on research from the literature, we provide a number of case studies that inform our hypotheses and provide guidance for future research.
This chapter can be found in the larger edited work “The Arc of Life: Evolution and Health Across the Life Course”.