Many, if not most, people place far less importance on the sense of smell than on sight and hearing.

The current pandemic may have caused some to rethink, however.

At least that applies to all those who have been temporarily stolen by the new coronavirus of smell.

A loss of the sense of smell restricts the quality of life in the long term, yes it can sometimes lead to depression.

Those affected find it particularly stressful that everything tastes equally bland, whether canned ravioli or sumptuous delicacies.

What many only then become aware of: In order to recognize the different flavors of a food, an intact olfactory organ is essential.

Because most culinary delights have their origin in the nose.

The tongue plays a subordinate role in this regard.

It can only perceive five rudimentary tastes, including sweet, salty, sour, bitter and spicy (umami).

Greater indulgence for noisy infants

Smells not only determine the desire to eat, but also influence a number of other areas of daily life. How they guide our behavior and that of other living beings, Bill Hansson, Director of the Max Planck Institute for Chemical Ecology, has compiled in the recently published book “The nose ahead” comprehensively, but never in a lengthy manner. With clear examples, the neuroethologist and olfactory researcher explains in a way that is understandable even for laypeople why the sense of smell in our perception wrongly ekes out a wallflower existence.

For example, he describes how some plants whitewash their own smell with other scents in order to distract hungry insects from themselves and to warn neighboring conspecifics of the impending attack.

The passages on the sometimes winding path of knowledge of research are also instructive.

For a long time, birds were denied a sense of smell because the attempt to lure certain vultures to an invisible animal carcass had failed.

It later emerged that the birds had abandoned the hidden carcass because of its too strong odor of decay.

Because they prefer animals that have recently died.

Future scented landscapes

The human nose also does more than is generally thought to be. Research by the author shows that infants emit a smell that blindfolded adults are able to distinguish from older children. Particularly surprising: fathers performed better than mothers and childless women. According to Hansson, this could be due to the fact that the test subjects perceived the infant scent as calming and sweet. To explain the phenomenon in more detail, the author goes back tens of thousands of years, because possibly the "aggressive male hunters showed greater indulgence with the noisy little babies on their return to the cave because of the wonderful smell".

Hansson doesn’t stop at introducing his readers to the fascinating world of smells. At the same time, he shows them how man gradually destroys them. The increasing littering of the environment affects, among other things, the ability of plants and animals to orient themselves in the realm of fragrances and to find suitable partners, to protect themselves from predators and to satisfy their hunger. To give an example: When rotting, the plastic waste in the oceans releases the volatile substance dimethyl sulfide, the smell of which attracts albatrosses and other marine life. Because the same gas excrete krill crabs when they digest phytoplankton. Therefore, the plastic ends up in the stomachs of the deceived birds - with sometimes fatal consequences.

One signal for this development is the increasingly rapid extinction of species.

It remains to be seen whether the remaining living beings will be able to adapt to the damaged environment and its changed smells.

At the same time, the author's remarks leave little doubt that the scented landscapes of the earth will change fundamentally in the future.

Bill Hansson: “The nose ahead”.

A journey into the world of the sense of smell.

Translated from the English by Sebastian Vogel.

S. Fischer Verlag, Frankfurt am Main 2021. 400 pp., Hardcover, € 24.