In a recent short article in The Journal of Experimental Biology titled “JUMPING BRISTLETAILS – A GLIMPSE INTO THE ANCIENT INSECT NOSE“, postdoc Katherine Parisky discusses the evolution of the olfactory system in insects.

In order for aquatic organisms to have made the transition from living in water to surviving on land, mutations in several physiological processes needed to occur. For one sensory system, that of smell, olfactory brain structures that detect odors based on sensing air-borne, volatile and hydrophobic molecules evolved from structures that had the ability to detect aqueous hydrophilic solutions […]

Read more at http://jeb.biologists.org/content/214/23/vi.full