Why did variations appear in the skin coloration of the human species?

Why did variations appear in the skin coloration of the human species?

Variations in human skin color are adaptive traits that correlate closely with geography and the sun’s ultraviolet (UV) radiation. Since strong sun exposure damages the body, the solution was to evolve skin that was permanently dark so as to protect against the sun’s more damaging rays.

How is skin color evidence for natural selection?

Darker skin protects circulating folate from being broken down. Some human populations migrated out of Africa to places where UV radiation was less intense. Here there was selection for lighter skin which let more UV radiation through for vitamin D synthesis.

What type of natural selection is skin color?

Natural selection may favour dark skin everywhere, though to a lesser extent at higher latitudes. Darwin believed that racial differences in skin colour were caused by sexual selection. Available evidence suggests that in each society a lighter-than-average skin colour is preferred in a sexual partner.

How is skin color in humans influenced by the environment?

The world-wide distribution of human skin color is highly correlated with the intensity of incident UV radiation. Thus, in places where the irradiation is very high, darker colors have been favoured, while at higher latitudes, where the irradiation is lower, lighter skins are predominant (Figure 2).

Why is there variation in skin color among modern humans quizlet?

– Human skin color variation likely evolved in response to differences in the intensity of sunlight around the world. – Human skin color variation is primarily determined by the type and amount of melanin pigment in the skin.

What does it mean to say that skin color patterns are the result of convergent evolution?

Traits shared by unrelated populations due to similarities of environment are examples of convergent evolution. Human skin color appears to be result of convergent evolution. Traits shared by unrelated populations due to similarities of environment are examples of convergent evolution.

What does a person’s skin color tell you about them?

Skin color alone does not provide any reliable information about a person’s race, culture or susceptibility to disease. However, skin color may offer insights into a person’s geographic ancestry. Scientists theorize that skin color evolved as an adaptive trait linked to the strength of the sun’s ultraviolet rays.

What are the three factors that affect skin color in humans?

The color of skin is influenced by a number of pigments, including melanin, carotene, and hemoglobin.

Is human skin color an 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.

Which of the following facts accounts for the variation in skin tone that exists between individuals?

Human skin color variation is primarily determined by the type and amount of melanin pigment in the skin. 2.

Why do people have different skin colors?

Variations in human skin color are adaptive traits that correlate closely with geography and the sun’s ultraviolet (UV) radiation.

Did the evolution of skin color change due to UV rays?

While UV rays can cause skin cancer, because skin cancer usually affects people after they have had children, it likely had little effect on the evolution of skin color because evolution favors changes that improve reproductive success.

Why did humans evolve to have dark skin?

Since strong sun exposure damages the body, the solution was to evolve skin that was permanently dark so as to protect against the sun’s more damaging rays. Melanin, the skin’s brown pigment, is a natural sunscreen that protects tropical peoples from the many harmful effects of ultraviolet (UV) rays.

What is the importance of human diversity in human evolution?

Modern Human Diversity – Skin Color. As people moved to areas farther from the equator with lower UV levels, natural selection favored lighter skin which allowed UV rays to penetrate and produce essential vitamin D. The darker skin of peoples who lived closer to the equator was important in preventing folate deficiency.