At the level of a mother’s basic biology, the decision to bottle feed unwittingly mimics conditions associated with the death of an infant. Child loss is a well documented trigger for depression particularly in mothers, and growing evidence shows that bottle feeding is a risk factor for postpartum depression. The implications of this hypothesis for infant feeding practices, hospital procedures that lead to intermittent separation between mothers and infants during the immediate postpartum period, parallels between an increased desire to hold infants by mothers who bottle feed and responses to infant death among nonhuman primates, and the relationship between weaning and depression are discussed in the context of an emerging discipline known as evolutionary medicine.