childbirth

Evolution theory held that women’s pelvises should have been shaped by the obstetrical dilemma (birthing babies with big heads safely) and thus should tend to be uniform. But The shape of a mother’s birth canal is a tug-of-war between two opposing evolutionary forces: It needs to be wide enough to allow our big-brained babies to pass through, yet narrow enough to allow women to walk efficiently. At least that’s been the common thinking. But a new study reveals birth canals come in a variety of shapes in women around the world. Erica Tennenhouse, “Birth canals are different all over the world, countering a long-held evolutionary theory” at Science Paper. (open access) Funny, the things that happen when people actually test Read More ›