The wheel, a round invention

The wheel is one of the most important inventions of Humanity, a true icon of mobility. It was invented approximately 6,000 years ago in the Middle East, and in parallel it was also invented in Mesoamerica 3,500 years ago, but pre-Columbian civilizations only used it in toys. Initially it was solid wood, later the spokes were introduced, and finally the rubber tires were manufactured. Today, any vehicle, even those we have sent to the Moon or Mars, are equipped with wheels. The wheel is also essential in gears and pulleys. However, natural selection has not incorporated them into the animal world because they have two insurmountable disadvantages: there are no sufficiently smooth ecosystems, and anatomically it is impossible to keep them connected to the rest of the organism (the axis must turn free). Humans have been inspired by birds to build the wings of airplanes, in mollusks Nautilus to design submarines, and observing the movement of tetrapod animals we have built vehicles that move on foot. But the fundamental mechanism is based on rotating motors and gears. In the world of technology even when we build legs, we cannot give up the wheels.