What does fortune-telling conch mean?

People who live by the sea often have the pleasure of picking up shells on the beach, while those who grew up in the inland often catch snails after the rain, so many people have noticed that almost all snail shells are twisted to the right, and left-handed people are extremely rare-this is the famous "academic difficulty under the nose", that is, the evolution of animals is dominated by the axis.

The snail shell is a stable object, and there is no real manipulation, so in order to break the difference caused by the observation direction, the twisting direction of the snail shell is defined as the side direction of the snail shell when the top of the snail faces the observer.

On the left is a left-handed snail with an opening on the left; On the right is the whirlpool, and the opening is on the right.

According to the current statistics, Gastropoda (Mollusca), that is, all kinds of snails, snails, slugs and so on. Is the second class of all living things, second only to arthropods, with 60,000 to 80,000 species, accounting for about 5% of all species in the animal kingdom-but only a little more than 65,438 species of gastropods recorded are left-handed.

All kinds of gastropods are right-handed.

In view of this sign of severe imbalance, it was thought that the twisting direction of snail shells was related to the earlier rotation of the earth, but this hypothesis was really untenable: on the standard of such a small snail shell, the weak influence of Coriolis force was not enough to talk about, and there were more right-handed snails in both the southern hemisphere and the northern hemisphere.

New Zealand's giant carnivorous snail not only lives in the southern hemisphere, but also is one of the very large land snails, but there are no more left-handed individuals.

In the current explanation, we pay more attention to the relationship between snail shell rotation and reproduction: Gastropoda mollusks all over the world exchange sperm in this way, while Gastropoda mollusks not only twist their snail shells, but also all organs, including reproductive system, are concentrated on one side of their bodies, so just like screws and nuts, a snail can only mate with its own rotating snail.