Science of Smell Points to Design

New research shows the sense of smell has even more complexity than previously thought.

“Codes, information, efficient strategies—this is intelligent design territory,” Discovery Institute experts wrote of the findings on the organization’s blog.

Researchers from Peking University in China built on what scientists already knew about the olfactory system. As molecules of odorants—substances that give off a smell—flow into the nasal cavity, they bump into receptor cells on tiny hair-like projections called cilia. An odorant molecule must have a specific shape and composition to bind to a specific receptor and trigger electrical impulses that instantly flow along nerves to the brain.

In a study published last month by Nature Communications, researchers reported new findings from fruit flies about how the olfactory system works. Until now, scientists assumed olfactory receptors worked by sending a simple yes-or-no response to the brain. But, much to the researchers’ surprise, they discovered that when a receptor cell fires, it can generate either an excitatory or inhibitory signal. In the nervous system, excitatory signals trigger certain behaviors that might involve something like moving away from a bad odor or toward a pleasant aroma. Inhibitory signals generally decrease behavioral responses.

The new research shows the olfactory bulb in the brain not only needs to process information about…