Human skin was not always afraid of the sun

(ORDO NEWS) — Man has a contradictory relationship with the sun. People love sunshine, but then they get hot. Sweat gets into your eyes.

Then all protective equipment is used: sunscreen, hats, sunglasses. If you’ve been in the sun for too long or haven’t taken enough precautions, your skin will let you know in the form of a severe sunburn.

Have people always been so obsessed with what the sun can do to their body – no, and there was no need for it.

Humans have evolved under the sun. Sunlight has been a constant presence in people’s lives, warming and guiding them through the days and seasons.

Homo sapiens spent much of their prehistory and history on the street, mostly naked. The skin was the main link between the body of our ancestors and the outside world.

The human skin was adapted to any conditions in which it found itself. People took shelter when they could find shelter in caves and rocks, and also learned how to make portable shelters from wood, animal skins, and other collected materials.

At night they huddled together and were probably covered with fur “blanket”. But during the active daytime hours, people were out in the open, and their mostly bare skin was what they had.

Throughout a person’s life, the skin reacts to regular sun exposure in different ways. The surface layer of the skin – the epidermis – becomes thicker due to an increase in the number of cell layers.

In most people, the skin gradually darkens as specialized cells begin to produce a protective pigment called eumelanin.

This remarkable molecule absorbs most of the visible light, causing the skin to appear very dark brown, almost black. Eumelanin also absorbs harmful ultraviolet radiation.

Depending on genetics, people produce different amounts of eumelanin. Some have a lot of it and are able to produce much more when their skin is exposed to the sun; others have less of it initially and produce less when their skin is exposed to the sun.

Studies on the evolution of human skin pigmentation have shown that the skin color of humans in prehistoric times was tuned to local environmental conditions, most notably local levels of ultraviolet radiation.

People who lived under strong ultraviolet radiation – such as those near the equator – year after year had darkly pigmented skin capable of producing a lot of eumelanin.

People living in weaker and more seasonal ultraviolet radiation, such as those in northern Europe and northern Asia, had lighter skin capable of producing only a limited amount of protective pigment.

Our distant ancestors, who moved only on their feet, moved little during their lives.

Their skin adapted to the subtle seasonal changes in sunlight and UV radiation, producing more eumelanin and getting darker in the summer, then losing some of the pigment in the fall and winter when the sun wasn’t as strong.

Even in people with lightly pigmented skin, painful sunburns were extremely rare because there was never a sudden shock from intense sun exposure. Rather, as solar radiation intensified in the spring, the top layer of skin gradually thickened over weeks and months of sun exposure.

This doesn’t mean that the skin wasn’t damaged by today’s standards: Dermatologists would be appalled at the leathery and wrinkled appearance of our ancestors’ sun-exposed skin.

The color of the skin, like the level of solar radiation, changed with the seasons, and the skin quickly showed its age. This continues to be the case for people living a traditional lifestyle, mostly outdoors, in many parts of the world.

Scientists have not preserved skin from thousands of years ago, but the effects of sun exposure on modern humans suggest that the damage was similar. Chronic exposure to the sun can lead to skin cancer, but rarely to the variant melanoma, which can cause death in reproductive age.

Living indoors has changed the skin

Until about 10,000 years ago – a drop in the ocean of evolutionary history – people made their living by gathering, hunting and fishing.

Humankind’s relationship with the sun and sunlight has changed a lot since humans began to settle down and live in permanent settlements. Farming and food storage were associated with the development of immovable buildings.

By about 6000 B.C. many people around the world began to spend more time in walled settlements and more time indoors.

While most people still spent most of their time outdoors, some stayed indoors whenever possible. Many of them began to protect themselves from the sun when they went outside.

By at least 3000 B.C. a whole sun protection industry arose, creating all sorts of devices – umbrellas, umbrellas, hats, tents and clothing – that protected people from the discomfort and inevitable darkening of the skin associated with prolonged exposure to the sun.

While some were originally reserved for the nobility such as the umbrellas and parasols of ancient Egypt and China these luxury items began to be made and used more widely.

In some places, people even created protective pastes from minerals and plant residues – early versions of today’s sunscreens – to protect their exposed skin. Some of them, such as the tanaka paste used by the people of Myanmar, have survived to this day.

An important consequence of this practice in traditional agricultural societies was that people who spent most of their time indoors saw themselves as privileged, and their fair skin spoke of their status.

“Farm tanning” was not glamorous: sun-darkened skin was a punishment associated with hard work outdoors, not a sign of leisurely relaxation. From Britain to China, Japan and India, tanned skin was associated with working life.

As people have moved more and faster over longer distances and spent more time indoors in recent centuries, their skin has not kept up with their location and lifestyle.

The level of eumelanin in your skin is probably not quite adapted to the sunny conditions in which you live, and therefore not able to protect you in the same way that your ancient ancestors did.

Even if you have naturally dark pigmentation or are capable of sunbathing, everyone is susceptible to damage caused by episodes of sun exposure, especially after long breaks away from the sun.

The “holiday” effect of sudden high UV exposure is really harmful because sunburn signals skin damage that never fully heals. It’s like bad debt, which after many years manifests itself in the form of premature aging or precancerous skin conditions.

There is no such thing as a healthy tan – a tan does not protect you from further damage to your skin by the sun, it is itself a sign of damage.

People may love the sun, but we are not our ancestors. Humankind’s relationship with the sun has changed, which means you need to change your behavior to save your skin.

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