Human newborns arrive remarkably underdeveloped. The reason lies in a deep evolutionary trade-off between big brains, bipedalism and the limits of motherhood.
Early in pregnancy, something surprising happens. Every human embryo develops a tail. It is not symbolic or imagined. A real extension forms at the base of the spine, complete with vertebrae. Later, ...
Medical intervention in human birth has become so widespread that spontaneous delivery is an increasingly rare event. Yet convincing evidence reveals an underlying 24-hour biorhythm, reflecting a ...
Medical intervention in human birth is now so widespread in industrialized countries that deliveries are seldom spontaneous. Yet with no intervention there is clear persistence of a general mammalian ...