Ancient humans had the same sense of smell, but different sensitivities

If you had Neanderthal grooming habits, it’s probably a good thing your nose wasn’t as sensitive to urine and sweat as modern humans.

And if you lived the Denisovan hunting-and-gathering lifestyle of the Asian steppes, your strong nose for energy-rich honey was certainly an advantage.

Although we can’t really tell what made these two go extinct Human From the species they are seen or preferred to eat, a new study by Duke University scientists has found out more about what they can smell like.

Using a technique they developed that allows the researchers to test odor sensitivity odor receptors Grown in a lab dish, researchers Claire de Marche of CNRS Paris Saclay and Hiroaki Matsunami of Duke University were able to compare the scenting abilities of three human species. Their work appeared December 28 in the journal Open Access iScience.

Drawing on published databases of genomes, including ancient DNA assemblies collected by 2022 Nobel laureate Svante Pääbo, the researchers were able to characterize the receptors for each of the three. human species By looking at related genes.

“It is very difficult to predict the behavior of just who Genetic sequencesaid DeMarsh, who conducted this work as a postdoctoral research associate at Duke University. “We had the odor receptor genomes from Neanderthals and Denisovans and could compare them to today’s humans and determine if they resulted from a different protein.”

They then tested the responses of 30 people in the lab olfactory receptors of each hominin against a set of odors to measure the sensitivity of each type of receptor to a particular scent.

the Lab tests showed that modern and ancient human receptors detect essentially the same odors, but their sensitivity differed.

Denisovans, who lived 30,000 to 50,000 years ago, have been shown to be less sensitive to scents that present-day humans perceive as flowers, but they are four times better at sensing sulfur and three times better at balsams. And they were very harmonious with honey.

“We don’t know what Denisovans eat, but there are some reasons why this receptor is sensitive,” said Matsunami, a professor of molecular genetics and microbiology at Duke School of Medicine. Modern hunter-gatherers like the Hadza community in Tanzania are famous for their love of honey, a high-calorie staple fuel.

Neanderthals, who were still around 40,000 years ago and who apparently swapped quite a few genes with modern humans, were about three times less responsive to green, floral and spicy scents, using pretty much the same receptors we have today. “They may show different sensitivity, but the selectivity remains the same,” Matsunami said.

“The odor receptors of Neanderthals are mostly the same as modern humans’, and the few that were different weren’t more responsive,” added de March.

Odor receptors have been linked to environmental and nutritional needs in many species and are presumed to evolve as species, ranges and diets change.

Each species must develop a sense of smell receptors Matsunami said to “maximize their fitness to find food.” In humans, it’s much more complicated because we eat a lot of things. We’re not really specialists.”

The lab also used the cell-based odor tester for vision Genetic variation in between modern humans. “Some people can smell certain chemicals, but others can’t,” Matsunami said. “This could be explained by functional changes.”