3D simulation of the birth canal of chimpanzees with (B) the fetal head in a fully extended position, the typical head alignment in apes, and (C) the fetal head in a fully flexed position, the usual ...
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, ...
According to a new study, chimpanzees, like humans, must contend with a confined bony birth canal when giving birth. In humans, the problem was exacerbated by our unique form of upright walking since ...