In fact, the trunk of an elephant is a modification of the nose and upper lip. From their fusion and elongation, an amazing organ was obtained: it has no bones at all and very little adipose tissue, but there are almost 150 thousand small muscles. Because of this, the trunk of the elephant is suitable for very subtle manipulations-lift a raw egg from the ground, break the nutshole shell without crushing the nut, remove the footping from the eye-and for hard work: an adult scrap can raise a trunk to 350 kilograms.
There are several hypotheses about how proboscis. The first is water: the proboscis is stretched out of elephant embryos at very early stages of development, the same -nilled evolutionary biologists believe that the common ancestor of the trunk could acquire a trunk long before the appearance of modern elephants. And some of these ancestors spent all their lives in the water, like Lamantins, or most of it, like hypothamas, and a long trunk allowed them to breathe from under the water. This theory is evidenced by some features of elephant anatomy – in particular, the thick wall of the sternum between the lungs and the ribs, designed to protect the lungs from high pressure.
Some scientists say that the water lifestyle has nothing to do with it, and the trunk appeared in the proboscis when they had already reached land, and helped send more food to his mouth. These data are confirmed by computer modeling. Indeed, having a small mouth, you can eat a lot of grass only if there is a convenient tool for this. Giraffes have a similar evolutionary device – this is their long tongue. Critics of the hypothesis about the trunk as the main tool for half a year of food refer to the fact that the amount of food that the animal can eat depends not only on the “delivery products”, but also on the device of the digestive system and many other factors.
There is also a theory that the trunk grew up to compensate for the mass of tusks that appeared earlier when elephants had no trunk. Big tusks pulled down and interfered with grazing, and a flexible and strong trunk came to the rescue.