Published: July 21, 2021

Leakey Foundation grantee Anna G. Warrener, Assistant Professor of Anthropology, was recently featured on the Leaky Foundation Origin Stories podcast to discuss the “obstetrical dilemma.” A hypothesis that explains why babies are so helpless, and why childbirth is so difficult for humans compared to other animals, the obstetrical dilemma suggests that babies are born early so their big brains can fit through the mother’s pelvis (which can’t get any wider due to our method of bipedal locomotion). This problem, the idea says, is solved by an evolutionary tradeoff that increases risks to pregnant mothers who must struggle to birth bigger and bigger-brained babies through narrow birth canals.