1. Biology Of Skin Color
(Sub-Saharan African, Indian, Southern European, and Northern European)

2. We are all one color…Brown
The only difference is the shade
There are no people who actually have true black, white, red, or yellow skin.  These are commonly used color terms that do not reflect biological reality.

3. Skin color and race
There are NO reliable genetic markers for race. (ie. There is no gene for race)
The concept of race is questionable!
The “false” concept of race can be traced to the history of European colonization
As a species, all humans originated in Africa.

4. Subtle Differences
The brown color we all share is melanin produced my the melanocytes at the lowest level of the epidermis.
Protection for UV light
The skin uses UV light to produce vitamin D, BUT approximately an hour a week is all that is needed.
ALSO, and important to human evolution, UV breaks down folic acid (Vitamin B) in the body.
A lack of folic acid can lead to birth defects & deformed sperm

5. Geography
Near the equator the amount of sunlight is much more than what is needed.
Too much exposure increases the risk of birth defects, defective sperm & skin cancer.
Thus, an increase in melanin (which absorbs UV and protects the folic acid & DNA)

6. Evolution of Skin Color
Evolution of humans near the equator in Africa would thus benefit from an increase in the production of melanin.
As people migrated, particularly far north of the equator (less intensity and length of light) the need for UV (vitamin D) outweighed the protection from destruction of folic acid & UV (birth defects & cancer).

7. (Data for native populations collected by R. Biasutti prior to 1940.)

8. Amounts of Melanin and Other Color Factors
European Ancestry:
Low levels of melanin produced
Skin slightly transparent because of this
Pinkish hue comes form blood in the capillaries of the skin
Asian Ancestry:
May have a slight yellowish tinge
Carotene (a red-orange pigment) is found in the dermis and the highest level of the epidermis

9. Shallowness of Skin Color
Very little of the skin is actually involved in skin-color difference.
Everyone has melanin.
The ONLY difference is the presence or absence of carotene and the amount of melanin.