news @ nature.com - People track scents in same way as dogs - Human reputation for poor sense of smell is down to lack of practice.: "If you think only hounds can track a scent trail, think again: people can follow their noses too, a new study says. And they do so in a way very similar to dogs, suggesting we're not so bad at detecting smells — we're just out of practice.
Scientists have found that humans have far fewer genes that encode smell receptors than do other animals such as rats and dogs. This seemed to suggest that we're not as talented at discerning scents as other beasts, perhaps because we lost our sense of smell when we began to walk upright, and lifted our noses far away from the aroma-rich earth."