Is skin color an example of adaptation?

Is skin color an example of adaptation?

Skin color is a well-recognized adaptive trait and has been studied extensively in humans. Understanding the genetic basis of adaptation of skin color in various populations has many implications in human evolution and medicine.

Can humans blue skin?

Yes, it turns out, and a family living in Appalachia had the condition for generations. In their case, blue skin was caused by a rare genetic disease called methemoglobinemia. Methemoglobinemia is a blood disorder in which an abnormally high amount of methemoglobin — a form of hemoglobin — is produced.

How do humans adapt to exposure to UV radiation?

Human skin pigmentation is the product of two clines produced by natural selection to adjust levels of constitutive pigmentation to levels of UV radiation (UVR). Under these conditions, the primary selective pressure was to protect folate by maintaining dark pigmentation.

What factors contribute to skin color?

The color of skin is influenced by a number of pigments, including melanin, carotene, and hemoglobin. Recall that melanin is produced by cells called melanocytes, which are found scattered throughout the stratum basale of the epidermis.

How is methemoglobinemia treated?

Methylene blue is used to treat severe cases of MetHb, and doctors may prescribe ascorbic acid to reduce the level of methemoglobin in the blood. In severe cases, a person may require a blood transfusion or exchange transfusion. Oxygen therapy will also be provided, if required.

What is skin describe functions of skin?

The skin protects us from microbes and the elements, helps regulate body temperature, and permits the sensations of touch, heat, and cold. Skin has three layers: The epidermis, the outermost layer of skin, provides a waterproof barrier and creates our skin tone.

Why do some people have blue skin?

Yes, it turns out, and a family living in Appalachia had the condition for generations. In their case, blue skin was caused by a rare genetic disease called methemoglobinemia. Methemoglobinemia is a blood disorder in which an abnormally high amount of methemoglobin-a form of hemoglobin-is produced.

What is the importance of skin color in modern human diversity?

Modern Human Diversity – Skin Color. The darker skin of peoples who lived closer to the equator was important in preventing folate deficiency. Measures of skin reflectance, a way to quantify skin color by measuring the amount of light it reflects, in people around the world support this idea. While UV rays can cause skin cancer,…

Is there such a thing as skin color adaptation?

Skin Color Adaptation. Human skin color is quite variable around the world. It ranges from a very dark brown among some Africans, Australian Aborigines, and Melanesians to a near yellowish pink among some Northern Europeans. There are no people who actually have true black, white, red, or yellow skin.

Why does nature have selected people with darker skin?

Nature has selected for people with darker skin in tropical latitudes, especially in nonforested regions, where ultraviolet radiation from the sun is usually the most intense. Melanin acts as a protective biological shield against ultraviolet radiation.