Dogs see the world in yellow and blue

This summer I had a Corona. Thanks to two vaccinations and boosters, the course was easy. But something irritated me: for several days after that, despite the fact that my airways were clear, I almost did not smell it – vinegar did not pinch my nose, and cutting onions did not bring me to tears. Eating and drinking ceased to be enjoyable. Now I smell normal again, and even the olfactory perception of farting gives me pleasure again. I’ve been one of many people who think they’re best off without their sense of smell.

“This textbook opinion (…) is based on a culture that has long given too little importance to smells,” writes Ed Yong (40), a British science journalist from The Atlantic, in his recently published book. The German philosopher Immanuel Kant (1724-1804) was of the opinion that the sense of smell can only be described by comparisons – a sensation without words. In contrast, the Malays, as Yong reports, “have a complex vocabulary of smells.” If only humans have different sensory experiences, how different must the animal world be.

The trunk of an elephant, the beak of an albatross, or the forked tongue of a snake: these are all organs of smell. And catfish, so to speak, have a floating tongue: taste buds are distributed throughout the skin. “Even if animals have the same senses as we do, they can be in very different conditions,” writes Yong. “Some animals hear sounds where it seems to be completely silent, see colors where it is completely dark for us, and feel vibrations when everything is calm to us.”

Irritants of all kinds are constantly bombarding living beings on earth. Yong: “Light is just electromagnetic radiation. Sound is made up of pressure waves. Smells are small molecules.” In order not to drown in the sea of ​​these impressions, each view focuses on one main meaning. Dogs sniff every room with their thin noses, but they see only dichromatically: for them, the surroundings appear white, black, blue and yellow. They don’t see red. By the way, bees too.

“Color is fundamentally subjective,” Yong writes. “At its core, a blade of grass is just as slightly ‘green’ as the 550-nanometer light it reflects.” Almost anything an animal uses its eyes for can also be done in gray tones. Then why color? The reason lies in the sea, where all living things come from: when the brightness is constantly changing in moving water, it is difficult to tell whether a dark figure is the shadow of an enemy or a cloud over the sea. “Color vision — especially with opposite colors — provides consistency,” Yong says.

Each sense has its advantages and disadvantages, and each stimulus is useful under some conditions and useless under others. Therefore, according to Yong: “No species ever uses only one sense and excludes all others.” Dogs have excellent sense of smell, but their large ears must also be taken into account.

Ed Yong, The Amazing Senses of Animals – Explorations of an Immeasurable World, Kunstmann