In this chapter, we provide an orientation to 1) how behavioral ecology, with its focus on tradeoffs and the timing of key life-history events, shapes our understanding of variation in age at maturation and first birth, birth spacing and family size, and their implications for mate choice, parenting, and cooperative childrearing; 2) how reproductive ecology informs our knowledge of how and why reproductive processes, including the allocation of time and energy to pregnancy, lactation, growth, and senescence, respond to social and ecological factors; 3) and how recent developments in evolutionary medicine and public health inform the ways in which evolved adaptations shape health, survival and fertility outcomes. Together these tracts in biological anthropology advance our understanding of the evolutionary and biological underpinnings of reproduction, the constraints and opportunities that influence reproductive processes, and contemporary issues such as teen motherhood, precocious puberty, small family sizes, changes in birth mode, and immune function, among other topics. We briefly situate the history of these fields and their relationship to other anthropology subfields, academic disciplinesm and sciences. We conclude with suggestions for future exploration, underscoring the need to increasingly develop cross-disciplinary dialogue within anthropology, and between anthropology and medical fields.