Biological and social evolutionary processes, along with social and cultural developments, have allowed humans to separate procreation from pleasurable/recreational sexual activity. As a class learning project, an alternative, hypothetical reproductive scenario is presented: "What if humans were biologically ready to conceive only during one period each year?" Discussion is followed by small-group or individual research on the possible effects of this scenario on human reproductive response and its further effects on human life, society, and civilization. An important purpose of the activity is to stimulate active learning through small-group interaction, communication, and research.