" human fetuses have a vomeronasal organ, though no one knows whether it’s functional. You can no more ask a fetus about these things than a python. Rawson surmises that the organ is a holdover from “when we were crawling out of the primordial soup,* and we needed to sense the chemicals in the environment and know which ones to go toward or away from. "

― Mary Roach , Gulp: Adventures on the Alimentary Canal