> Evolutionarily, it pays to have a nose that can pick up the minutest presence of thiols, says study co-author Eric Block, a chemist at the University at Albany, State University of New York. The sulfur compounds are released by rotting food, for instance, and some predators give off olfactory cues to their presence in this form.

Ah the classic, "Your body evolved to let you know when things will kill you". That's usually a successful evolutionary process.