Why do people have different skin colors? How do people with different skin colors differ? Why do we have different skin colors? People with different skin colors.

What is leather?

When we think about the human body, we are accustomed to refer to the heart, liver or brain as "organs." They have certain functions and they perform them. Did you know that the skin is also an organ of the body?

While other organs take up relatively little space, the skin spreads over the entire body in a thinnest shell with an area of 20,000 square meters. see The number of complex structures present in every centimeter, from sweat glands to nerves, is truly fantastic.

The leather is made up of two layers of fabric. One of them is a thicker and deeper layer, the so-called "corium", and on it is a thin tissue - "epidermis". They connect together in a wonderful way. The lower layer has outgrowths in the form of "papillae", which penetrate into the upper layer, thus linking them into a single whole.

Since these "papillae" are located in the folds, a pattern is created on each area of the skin. Our fingerprints are actually formed by these folds.

The top layer of the skin, the epidermis, does not contain blood vessels. It consists of cells that have already died and "keratinized". We can say that the human body is covered with a horny "shell". This is very beneficial as the stratum corneum helps protect us. It is insensitive, therefore it protects us from pain. Water has no effect on him, and he is even a good insulator.

However, the lowermost layers of the epidermis are very sensitive. Their job is to create new cells that are generated from the mother's cells and, as it were, are pushed up by them. Over time, they stop receiving nutrition and die off, turning into a stratum corneum.

Every day, billions of upper keratinized cells fall off in the course of our life. But fortunately, just as many new cells are produced every day. Therefore, our skin always remains youthful.

There are 30 layers of keratinized cells in the skin. As soon as the top layer of skin is washed off or rubbed off, a new one is ready underneath. We can never use all these layers, since a new one always rises from below. Thus, we have the ability to cleanse the skin of stains and dirt and keep it clean.

People with the whitest skin can be seen in northern Europe and are classified as Nordic. The blackest skinned people live in West Africa. The skin of the inhabitants of Southeast Asia is yellowish. However, most people are not white, black, or yellow, but represent hundreds of shades of light, tan, or brown.

What is the reason for all these differences in skin color? The explanation is in the chemical processes that take place in the body and skin. Skin tissue contains color components called "chromogens" that are colorless in themselves. When certain enzymes act on them, the corresponding skin color appears.

Imagine that a person does not have chromogens or their enzymes do not work properly on them. Such a person is called an "albino". This happens to people all over the world. There are albinos in Africa, and they are "whiter" than any white person!

Human skin by itself, without any substance, milky white. But to this is added a shade of yellow due to the presence of yellow pigment in the skin. Another color component of the skin is black, associated with the presence of tiny granules of melanin. This substance is brown in color, but in large quantities it appears black. Another shade is introduced into the skin by the red color of blood circulating through its tiny vessels. Each person's skin color depends on the ratio in which these four colors - white, yellow, black and red - are combined. All skin colors of the human race can be obtained by various combinations of these color components that we all have.

Sunlight has the ability to form melanin, a black pigment in the skin. Therefore, people living in the tropics have more of this pigment and darker skin. If you spend a few days in the sun, the sun's ultraviolet rays will also generate more melanin in your skin, resulting in a sunburn!

Why do people have different skin colors?

Human skin itself, without any substance, is milky white. But to this is added a shade of yellow due to the presence of yellow pigment in the skin. Another color component of the skin is black, associated with the presence of tiny granules of melanin. This substance is brown in color, but in large quantities it appears black. Another shade is introduced into the skin by the red color of blood circulating through its tiny vessels. Each person's skin color depends on the ratio in which these four colors - white, yellow, black and red - are combined. All skin colors of the human race can be obtained by various combinations of these color components that we all have.

What is the difference between people living on our planet? It is not so difficult to answer this question. Of course, physique, religion, race, gender, worldview, temperament and, most importantly, skin color. It can be white, black, dark-skinned, and have a reddish tint.

What is the reason for this?

To begin with, people with a certain skin color could be found only in certain areas of our planet. Redskins - in America, blacks - in the countries of the African continent, whites - in Europe. In this case, we are talking about the territories in which their ancestors lived, since in modern world due to the migration process, people with different skin colors can be found anywhere.

Of course, the place of residence has left its mark on the skin color of the people living there. Features of the climate, solar activity, zoning - all these factors, one way or another, affect the amount of melanin produced by special cells of the human body - melanocytes. But the color of human skin depends on the amount of melanin in the epidermis. The more this pigment, the darker the skin.

But back to the territory of residence, and how it affects the production of melanin. Let's take a simple example. The body of a person sunbathing in the sun takes on a dark complexion. This is because under the influence of sunlight, melanocytes begin to produce more melanin, which makes the skin darker. That is why people living in hot countries can have black skin. The thing is that they spend a lot of time in the sun, and their epidermis is maximally saturated with melanin. That's the whole secret of black leather.

In white people, melanin is either completely absent or contained in minimal amounts. Hence, the color of their skin can be white or have a pinkish tint, due to the presence in the skin a large number blood vessels. So, for example, albinos not only absolutely White skin and hair of the same color, but also a completely colorless iris of the eyes.

And yet, what role does melanin play in the human body?

As it turns out, its main function is to protect the skin from ultraviolet radiation from the sun. It's no secret that a person who has received an increased dose of solar irradiation runs the risk of developing skin cancer. Melanin, in this case, is a protective filter. It makes the skin darker and thus changes its reflectivity. It turns out that dark skin is less susceptible to ultraviolet rays.

But how, after all, did dark-skinned and white-skinned people appear?

Body ancient man was covered with a thick layer of wool that protected his skin from the ultraviolet rays of the sun. In the process of evolution, the hair on the human body began to disappear. Why this happened is not known for certain. One way or another, their skin turned out to be unprotected from solar radiation.

People living in hot countries were at particular risk. Representatives with dark and dark skin turned out to be in a more advantageous position. It was they who were able to survive in such extreme conditions. There was a very real natural selection, as a result of which the Negroid race appeared.

The exact opposite situation took place in people with white skin. They lived in the cold northern regions, with a small amount of ultraviolet radiation. With its lack, human bones become fragile, and vitamin deficiency occurs in the body. In such conditions, only people with lighter skin, which is able to absorb more ultraviolet radiation, could exist. They drove out dark-skinned people, whose skin blocked ultraviolet rays. For this reason, their offspring suffered from rickets, and the bones could not withstand the load and broke. As a result, only people with fair skin, whom we call white-skinned, were able to survive in these places.

When describing a person, we often include in this list and the characteristic of skin color or tones.

Such differences have arisen as a result of human evolution over many centuries and are associated with the place where people live on the planet.

You have probably noticed that the skin color of people living in the southern latitudes is much darker than that of those living in the north. This is due to the production of a special pigment in the body, melanin. It performs a protective function, protecting the skin from ultraviolet radiation, which can lead to skin burns or even more serious diseases. But the content and production of melanin occurs in all people in different ways, so some can be under the scorching rays of the sun for a long time, becoming more and more dark, while others just need to be in the sun for a few minutes, having received a skin burn, while a tan does not form ...
Sometimes you can meet unusually bright people. Their skin is very white, their hair is light and their eyes are red. They are called albinos. In their body, melanin may be partially or completely absent.

This congenital disorder is not a pathology and in nature it is not so rare, not only among humans, but also among other animal species. But for humans, this anomaly does not cause much inconvenience, while animals living in nature can hardly cope with the consequences that cause the absence of melanin in the body.

The most famous albino was recorded in 1991 off the coast of Australia. This is the humpback whale Migalu.

His skin is covered with numerous burns.

And the latest photographs provide us with proof that the whale has skin cancer.

The evolutionary process has shown that in southern latitudes, people with a dark skin color are more viable than their light counterparts. The survival rate of such individuals was higher, and, therefore, the offspring were born stronger, inheriting a dark skin color.

The bulk of the population of the equatorial regions have just this color.

In the northern regions of our land, the evolutionary process went in a different direction. The sun is not so hot here, and there is not much of it. Despite the fact that the body is trying to protect itself from the effects of UV rays, the sun's rays can be of great benefit to you.

Under their action, your body produces vitamin D. Lack of this vitamin, first of all, affects the skeletal system, causing a serious disease of rickets.

With this disease, human bones become weak and fragile, which can damage them even with a slight external influence. It was to him that for many centuries people with dark color skins living in the northern regions.

Just imagine, their skin is rich in a lot of melanin, which does not let the sun's rays through.

And the sun heats up weakly and not so often, and sunlight cannot break through such protection, which means that the body will not be able to produce the vitamin D it needs, therefore, in northern latitudes, light skin color is predominant.
But research by scientists proves that the presence of the sun is not the only factor affecting skin discoloration.

Changes are still taking place, which means that something else may have an impact on the shades. Researchers have suggested that this is due to human nutrition.

Its activity many millennia ago began with hunting and gathering, so vitamin D entered the body along with food, and when agriculture and cattle breeding replaced it, the body had to independently "learn" to produce it, which also affected the skin color.
Today, free movement around the world has made it possible for people to communicate more with representatives of a different race, which often leads to the creation of mixed marriages. As a result, nowadays people with different skin colors can be found anywhere in the world.

We will continue to educate ourselves =). Since we were analyzing skin color, today there is some popular science information about skin color. Let's remember combinatorics and genetics.
Information used
http://halibi.livejournal.com/231820.html#cutid4

Skin color depends on three elements - melanin (saturation, Brown color), hemoglobin (reddish tint) and carotene (yellowish tint). Each person has their own combination of these three elements, which gives a unique skin tone. In men, the skin is slightly darker - hormones also affect. The skin on different parts of the body is colored unevenly.

The darkness of the skin is influenced by melanin. Two genes are responsible for the production of melanin, each of which has two characteristics - dominant and recessive. The dominant characteristic is black skin, the recessive characteristic is white. But this does not mean that one constantly dominates - they mix. Therefore, 16 combinations are possible.

Let the first gene be marked with the number 1, and the second with the number 2. The dominant characteristic of black skin color will be M, and the recessive white skin color is m.

Let's decipher the picture

1 - М1М1М2М2 - all dominant characteristics - Black skin

2. MMMm- three dominant and one recessive characteristic - Dark brown skin.

3.MMmm - two dominant and two recessive characteristics - medium brown skin .

4. Mmmm - one dominant and three recessive characteristics - light brown skin color

5.mmmm - all characteristics are recessive - White color skin

There are transitional combinations between them.

If you wish, you can calculate how rich the skin your children can have if you are friends with combinatorics. Just for fun.
my type Mmmm, my husband's type Mmmm. We can pass two genes to a child. I got several combinations. Of these, some MMMm, some Mmmm, and mostly MMMM. Everything is predictable with us. =) The lightest skin color can be like mine, the darkest - like my husband's. And sometimes it is much more interesting - when the child is darker or lighter than both parents.

Carotene and hemoglobin determine the dominant skin tone (semitone) - either pink (hemoglobin) (top line of the picture), or yellowish (carotene) (bottom line of the picture)

Usually these semitones are taken into account by manufacturers. tonal means, but this will be a separate topic.

Anthropologists often use the Von Lushan scale to describe skin color. (Von Luschan Chromatic Scale)
To find out the color of your skin, look at the skin under your forearm, which usually does not tan.

Here is the natural version of the scale

Here's a more user-friendly digital

I cannot determine exactly my skin type - either 15 or 16. I can only say that it is clearly beige, i.e. not 14, and clearly not olive, i.e. not 17.16 seems to be closer, because the skin is a little yellowish on the hands - but the color may depend on the monitor settings ..

Skin saturation is closely related to phototype - the reaction of the skin to ultraviolet light. I will talk about this next time.