The article explores the evolutionary significance of grandmothering and menopause in human life histories. It argues that long postmenopausal lifespans, a unique feature of humans compared to other primates, may have evolved due to mother-child food sharing, which allowed aging females to enhance their daughters' fertility and increase selection against senescence. This hypothesis, combined with Charnov's dimensionless assembly rules for mammalian life histories, explains human traits such as late maturity, early weaning, and high fertility. The authors suggest that grandmothering could slow aging by either mutation-selection balance or inter-temporal tradeoffs in reproductive effort, leading to longer lifespans after menopause. They also discuss how this hypothesis challenges traditional ideas about human evolution, such as the importance of extended learning and paternal provisioning, and implications for past human habitat choice and social organization. The article concludes by suggesting that the evolution of these traits may have occurred around 1.8 million years ago with the emergence of Homo erectus, and possibly again around 600,000 years ago with early archaic sapiens, or around 50,000 years ago with anatomically modern sapiens.The article explores the evolutionary significance of grandmothering and menopause in human life histories. It argues that long postmenopausal lifespans, a unique feature of humans compared to other primates, may have evolved due to mother-child food sharing, which allowed aging females to enhance their daughters' fertility and increase selection against senescence. This hypothesis, combined with Charnov's dimensionless assembly rules for mammalian life histories, explains human traits such as late maturity, early weaning, and high fertility. The authors suggest that grandmothering could slow aging by either mutation-selection balance or inter-temporal tradeoffs in reproductive effort, leading to longer lifespans after menopause. They also discuss how this hypothesis challenges traditional ideas about human evolution, such as the importance of extended learning and paternal provisioning, and implications for past human habitat choice and social organization. The article concludes by suggesting that the evolution of these traits may have occurred around 1.8 million years ago with the emergence of Homo erectus, and possibly again around 600,000 years ago with early archaic sapiens, or around 50,000 years ago with anatomically modern sapiens.