Quick Answer: Why is cancer not the selective pressure for dark skin?


Was skin cancer a selective force for black pigmentation in early hominin evolution?

Here, I suggest that data on age-associated cancer incidence and lethality in albinos living at low latitudes in both Africa and Central America support the contention that skin cancer could have provided a potent selective force for the emergence of black skin in early hominins.

Why is skin cancer rare in dark skin?

The low incidence of skin cancers in darker skinned groups is primarily a result of photo-protection provided by increased epidermal melanin, which filters twice as much ultraviolet (UV) radiation as does that in the epidermis of Caucasians (Montagna and Carlisle, 1991).

What is the selective pressure for darker skin?

6. Indigenous populations in low-UV environments tend to have lighter skin tones. One hypothesis is that, in low-UV environments, the selective pressure for dark skin is low. Instead, there is selective pressure for lighter skin, which absorbs more UV radiation, since UV is needed for vitamin D production.

Is it harder for darker people to get skin cancer?

The bottom line. Although it’s less common, Black people can get skin cancer. In fact, skin cancer is often diagnosed later in Black people, making it harder to treat and potentially leading to a poorer outlook.

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Which subpopulation is at the greatest risk for vitamin D deficiency?

The subpopulation at the greatest risk for vitamin D deficiency is non-Hispanic black females. The subpopulation at the least risk for vitamin D deficiency is non-Hispanic white males.

Can folic acid cause pigmentation?

Deficiency of vitamin B-9 (folic acid) and B-12 (cobalamin) can cause pigmentation problems leading to patchy skin. Deficiencies of vitamins that occurs due to reduced intake of vegetables and fresh fruits can therefore make you skin appear dull and dark.

Does skin cancer have black dots?

Of all skin cancer-related deaths, 79% are from melanoma. In this disease, cancer develops in cells (melanocytes) that produce skin pigmentation. A black or brown spot appears, typically, on the torso of males and lower legs of females. It may also form on the palm of the hands, soles of the feet and under the nails.

What race has the highest rate of skin cancer?

Invasive melanoma of the skin is the third most common skin cancer type.


Race/Ethnicityb Rate Count
US Population
White 24.9 73,395
White, Hispanic 4.6 1,591
White, non-Hispanic 28.0 71,801

What is the color for skin cancer?

Colors and Months for Cancer-Related Ribbons

Cancer Ribbons
Skin cancer Black May
Skin cancer (squamous cell carcinoma) Red and white May
Small intestine cancer periwinkle blue
Testicular cancer Purple (orchid) April

How many generations does it take for skin color to change?

Some researchers suggest that human populations over the past 50,000 years have changed from dark-skinned to light-skinned and vice versa as they migrated to different UV zones, and that such major changes in pigmentation may have happened in as little as 100 generations (≈2,500 years) through selective sweeps.

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