Menopause is puzzling because life-history theory predicts there should be no selection for outliving one's reproductive capacity. Adaptive explanations of menopause offered thus far turn on women's long-term investment in offspring and grandoffspring, all variations on the grandmother hypothesis. Here, I offer a very different explanation. The patriarch hypothesis proposes that once males became capable of maintaining high status and reproductive access beyond their peak physical condition, selection favored the extension of maximum life span in males. Because the relevant genes were not on the Y chromosome, life span increased in females as well. However, the female reproductive span was constrained by the depletion of viable oocytes, which resulted in menopause.
Keywords: Grandmother hypothesis; Hadza; Life history theory; Male-male competition; Menopause; Oocyte depletion; Pair-bond; Patriarch hypothesis.