It turns out that animals also like to dip dumplings in vinegar? Why?

You have to dip dumplings in vinegar when eating them. Without vinegar, the taste always seems to be a little off.

Not only humans have this feeling, animals and humans have surprisingly similar feelings on this point. If you have ever fed your dog a dumpling dipped in vinegar, then the next time you give it dumplings, it will most likely signal you to dip it in vinegar. Of course, stuffing foods, represented by dumplings, are not suitable for pets due to their high salt content, so don't try it over and over again just because you think it's fun. But this is indeed a very interesting thing. Animals and humans have different taste perceptions. Many things that humans think are delicious are not delicious to animals, and things that animals think are delicious may not be of interest to humans. Why are animals and humans surprisingly consistent in the matter of "eating dumplings with vinegar"?

In fact, humans and animals are not interested in vinegar as a specific condiment, but generally prefer sour foods.

Different foods and different organisms taste different because each animal has different taste receptors. For example, except for primates, the livers of other animals cannot metabolize theobromine perfectly, so we always say that dogs can't eat chocolate. However, cats can't eat chocolate either, but we rarely mention it. Why? Because cats basically don't actively eat chocolate.

Cats won't actively eat chocolate because they lack sweet taste receptors and can't sense sweetness. So chocolate is a bitter lump to them and of course they won't eat it.

There are many similar examples. For example, dolphins cannot sense saltiness, which we consider to be the "basic taste". Different animals have very different taste receptors and taste buds, but all animals, whether vertebrates or invertebrates, have a taste that is never missing, that is "sourness". Isn't it interesting?

Animals have a sense of taste because they need to rely on taste to determine whether food is safe, so an animal's taste receptors are closely related to its eating habits.

By sensing sweetness, animals can judge that food has high calories, and by sensing saltiness, animals can judge that food has inorganic salts. Conversely, if bitterness is sensed, it means that the food may be dangerous. So what does sourness mean? Why has no animal lost its sour taste receptors in hundreds of millions of years of life evolution? For scientists, sour taste receptors are the most mysterious of all taste receptors, because it was not until 2019 that scientists first discovered an ion channel, OTOP1, in the tongue sour taste receptors in mice.

It is very easy to figure out the evolution of other taste receptors because each taste receptor protein corresponds to a genetic information, but the OTOP1 gene that controls sour taste is very widely expressed.

In other words, OTOP1 is not only related to the perception of sour taste, but also closely related to the development of other parts of the body, which makes it difficult for scientists to infer the evolution of sour taste by comparing the differences in OTOP1 genes between species. But one thing is certain, that is, in the long process of biological evolution, many animals have lost part of their sense of taste, but the perception of sour taste has never disappeared in any animal.

If the perception of sourness has been preserved, it must have some important meaning.

Scientists believe that primates have lost the ability to synthesize vitamin C in their bodies, so they need to identify sour tastes to find foods rich in vitamin C. For other animals, rotten plants and animals are an important part of their food source, and identifying sour tastes can effectively determine whether rotten plants and animals are safe, because foods with a specific sour taste represent high levels of lactic acid bacteria and acetic acid bacteria, and the acids secreted by these beneficial bacteria kill harmful bacteria. So if the sour taste in rotten plants and animals completely masks other tastes, it means that these foods are generally safe.