According to a new study, chimpanzees, like humans, must contend with a confined bony birth canal when giving birth. In humans, the problem is exacerbated by our unique form of upright walking, since ...
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 ...