Human noses know more than 1 trillion odors

Smell played an underappreciated role in evolution

SMELL DETECTORS  A researcher whiffs a scent-containing vial used in experiments indicating that people can identify at least 1 trillion different odors.

Zach Veilleux/The Rockefeller Univ.

Respect the nose. Humans use it to tell apart an average of more than 1 trillion odors, a new study finds.