Olfaction

The sense of smell is one of nature's true wonders, capable of detecting and identifying thousands of diverse odorants at extremely low concentrations. Along with its sister sense of taste, this sensory system is the most ubiquitous in the animal kingdom, occurring in one form or another in nearly all air-, water-, and land-dwelling animals. Even single-celled organisms, such as amoebae and paramecia, have mechanisms for sensing environmental chemicals. In our own species, the sense of smell plays a significant role in daily life, largely determining the flavor of foods and beverages and providing an early warning for such environmental dangers as leaking natural gas, fire, toxic fumes, spoiled foods, and polluted environments. Indeed, all environmental nutrients and airborne chemicals required for life enter our ...