One of the skin’s many functions is to make vitamin D, by harnessing the Sun’s rays. However, ultra-violet light from the Sun can damage the skin, so the body produces a substance called melanin to protect it. Melanin is what makes skin look darker or lighter.
Skin colour
Human skin has adapted to suit the conditions on Earth. Near the Equator, the Sun’s rays are most intense. The body produces lots of melanin for maximum protection, so skin is darker. Far from the Equator, less melanin is needed, so skin is lighter.
Dark skin
Lots of melanin is produced by cells called melanocytes.
Pale skin
The skin produces smaller amounts of melanin pigment.
Freckles
Some people have a gene for freckles. These small dots show where s=many melanocyte cells have grouped together. They can become more visible when exposed to sunlight.
Freckled face
Freckles are most common on the face, but they appear on arms and shoulders too.
Picture Credit : Google