Join us on April 29th at 12:15pm in Beach Hall Rm 404 for a guest lecture by Professor Holly Dunsworth.
There Is Still No “Obstetrical Dilemma” in Human Evolution:
It has been about 15 years since I led a critique of the “obstetrical dilemma.” Considering comparative zoological, biomechanical, metabolic, energetic, and other factors, we argued against the theory that human gestation is reduced to solve the difficult birth caused by antagonistic selection for narrow bipedal hips and large neonatal brains. We proposed that the tight fit at birth is a coincidence, and not an evolutionary cause of the evolution of what anthropologists have long called our “altriciality” (or extreme helplessness) as infants. Since then, researchers have continued to assume and to even defend the “obstetrical dilemma.” In doing so, a group of researchers redefined it. In 2023, they removed the idea of an early birth, but kept the gist of the “dilemma”: an evolutionary limit to the size of the pelvis is limiting gestation. Alongside the last 15 years of pro “obstetrical dilemma” research, I and others have launched further critiques, with two of mine arguing that “there is no obstetrical dilemma.” In this talk, I share new insights and arguments that lead to the same conclusion, even with the recent change to the definition of the idea. One fundamental issue with the “obstetrical dilemma” is the hyper-focus on pelvis and fetal size. In the current culture of science, the analysis, estimation, and modeling of quantitative, anthropometric data permits researchers to effectively ignore what is known and unknown about physiological birth. At the core of the conflict between adherents to and critics of the “obstetrical dilemma” are different views of how evolution works—including what evolutionary science is capable of discovering about the past and present. Can we know the selection pressures of the past? Can we know the limits to evolution then or now? The “obstetrical dilemma” is only as good as the logic, evidence, and assumptions that go into it. In this talk, I argue that it fails on all three fronts. The “obstetrical dilemma” is unnecessary for an evolutionary perspective on childbirth. The only truth to the “obstetrical dilemma” is the real-life impact it makes on people’s experience of childbirth. The reality of the “obstetrical dilemma” is not scientific but mythic.