Beijing time July 17 news, according tomedia reports, if you are self-rolled, and very envious of other people’s straight hair, you may wonder why other people’s hair can keep smooth and smooth, but their own roll mess. A study published in the Journal of Experimental Biology in 2018 suggests that there may be two theories that explain the phenomenon.
The first hypothesis suggests that the curls are caused by more hair cells growing on the raised side of the hair follicle (i.e. on the outside of the hair roll), while the number of cells on the side of the hair follicle depression is relatively small. As a result, the hair follicles are pulled inwards, causing hair to change.
Another theory is that different cell lengths on the raised side of the hair and the recessed side lead to the formation of curls. Similar to the first theory, the theory is that the outer cells of the hair are relatively slender and the inner cells are firmer, causing the hair to curl.
Scientists believe that curly hair is better for mammalian strains than pure straight hair. In fact, the straight hair is the last line of defense against hair loss.
The typical structure of mammals with hair is like a bush-born forest. Straight hairs stand firm, “creating a space on the surface of the skin” and “smaller curls fill up and keep air in it.” “
However, the study only solved the problem of the long curly hair of beautiful slave sheep. It is much more difficult to study whether humans have evolved curls for the purpose of keeping them warm. Since technologies such as hats replace some of the functions that were originally biologically responsible, it is difficult to determine the exact cause of long human curls.
However, we still know a lot about the origin and biology of human hair follicle characteristics from mammals. Because if we go back long enough, our hairs in other mammals actually evolved from the same source. Mammals have a long history of hair, probably before dinosaurs appeared. (An analysis of 29 fossilized skulls of animals (close relatives of ancient mammals) showed that the mammals’ predecessors were hair-haired, according to a 2016 study published in the journal Scientific Reports. )
To test both theories, the researchers used high-precision microscopy to multiply sheep’s wool fibers and then measure the number and size of cells inside and outside the wool bend. Almost immediately, they found evidence to counter the claim that “different numbers of cells lead to hair curls”, with all the outer cells at the bend shorter than the inside, supporting the second theory that the curldegree of the hair is determined by the length of the cell.
However, the situation is not so simple. The study analyzed only the cross-section of a single wool fiber under a microscope, and the pattern of the hair at this angle may be the arc of the hair itself, or it may be formed by the torsional force, which causes some interference with the analysis results.
Moreover, even if these cross-sections perfectly represent the shape of the hair itself, that doesn’t mean that another theory (i.e., “cell number”) is wrong, because different animal hair curls for different reasons may vary. (Leaf)