Every nation has its own distinctive skin tone. Europeans have pale skin, and Asians have dark, yellowish skin. People on the African continent have a black color, reaching almost black. Perhaps everyone knows that the color of their skin is related to the climatic peculiarities of the region where they live: the closer to the equator, the darker the skin.
But why is this so? Black heats more in the sun, more susceptible to heat, which in the heat is completely unnecessary. Southerners have darker skin color despite this. How has nature allowed this to happen?
Dark skin: pros and cons
Black has a knack for catching the sun’s rays and heating more quickly. Going out in the street in a dark T-shirt in the summer, on a sunny hot day, a person can feel how much his back gets hot, while another passerby in light clothing will feel quite comfortable. Nature actively uses such an additional opportunity to warm the living body – not everyone knows that under the light fur of the polar bear hides a completely black skin, capable of catching even the scarce northern rays. But why the extra heat for Africans?
Indeed, in the tropics and on the equator, there is no problem with heat. It is unnecessary to catch every ray. Rather, on the contrary, it is important to get rid of excess heat – therefore African and Northern peoples have a completely different distribution of fatty tissues in the body. In people with northern roots, fat is distributed all over the body, providing protection, and in Africans it is localized in certain areas, leaving the rest of the body open for active heat exchange to get rid of excess heat.
Dark skin is also optimally suited to this climate, with an increased protective function. Its primary function is not to remove the risk of overheating, but to filter out ultraviolet light. The closer we get to the equator, the more of it comes in with the sunlight, and the melanin pigment, which makes our skin darker, provides excellent protection from its effects. Excess UV light damages cellular DNA and can increase cancer risks, so too much exposure is not acceptable.
Interesting fact: Sun exposure tanning is also a protective reaction. Skin darkens quickly in the sun to give the body protection.
Light skin and ultraviolet light
Without ultraviolet light, humans can not do without it either, because it is its presence that allows the body to synthesize vitamin D on its own. In northern latitudes, the body must do everything possible to capture enough light to produce one of the most important vitamins, without which even the synthesis of calcium is impossible – so at a distance from the tropics, people live with fair skin, which has only minimal protection, does not reflect UV light, but uses it in full available.
Scientists say that humanity emerged from Africa, where the evolution of our species took place. It is assumed that Homo sapiens as a species came to Europe as black, neighboring light-skinned Neanderthals for a certain period. However, later on, the skin became lighter and then completely white – the human organisms adapted to the new climatic conditions.
Today, the skin of some northerners contains almost no melanin – they cannot even tan under the sun. For such people, high sun exposure is dangerous, because there is no natural protection. Tanning can lead to the destruction of the skin due to sunburn, and constant sun activity mushrooms their risk of skin cancer. Fortunately, the modern cosmetology industry offers many solutions to this problem, and in particular, people can use sunscreens on vacation so as not to create risks for the body.
Dark skin is associated with brown eyes, and the iris shade of southern residents can go up to almost black. It is also related to protective functions because the eye as a delicate organ of vision should be protected even more. Northern latitudes gave birth to blue-eyed nations with lighter irises, as well as several other body features that allowed people to adapt to the small amount of sunlight, low temperatures, and other nuances.
So black provides quick heat, but that’s not the major factor. The major factor becomes UV protection. It is the black skin that gives it the maximum amount.