Lab-grown ancient nose receptors reveal how our ancestors smelled

There’s still plenty we don’t know about how these archaic species lived, but clues can lie in their genes. So for the new study, researchers at Paris Saclay University and Duke University grew odor receptors of Neanderthals and Denisovans in lab dishes, exposed them to different odors and measured their sensitivity compared to that of our own.

The team started by poring over databases of genomes of the different species, including those assembled by last year’s Nobel Laureate, Svante Pääbo. They could then compare specific odor receptor genes to those in modern humans to work out how much each one differed. From this, they then grew 30 odor receptors from each hominin, exposed them to various smells and measured their responses.

The team found that the receptors mostly detected the same odors across the board, but differed greatly in their sensitivity to different smells. Neanderthals seem to have had much the same sniffers as we do now, with only a few genes differing – and counter to what you might expect, those changes were mostly for the worse. Neanderthal-specific receptors were significantly less sensitive to spicy, sweet, minty and floral smells than modern humans. On the plus side, they were also less sensitive to the smells of sweat and urine, which would no doubt be beneficial in a world before daily hygiene routines.

Denisovans, on the other hand, differed more broadly in their olfactory responses. They were less sensitive to floral scents, but were four times better than us at picking up “sulfurous” smells and three times more sensitive to balsamic scents – thick, sweet smells like vanilla and chocolate. They also responded well to the smell of honey, which the team hypothesizes may have been a favorite food of theirs, given its richness in energy.

Image source: Bacon Cph / Wikimedia Commons.