The list of glands in skin of mammals is long - sebaceous glands, ceruminous glands, sweat, lacrimal , mammary, meibomian, perineal, prepucial glands Sebaceous glands are related to pimples and acne. Had the earwax not been produced perhaps, insects would have laid their eggs in the warm, soft, dark tunnel of our ear canals. The answer is in the article. The skin colors vary in man to a great deal depending on concentration of a single pigment-the melanin. Melanocytes in skin produce melanin.
Sunlight darkens skin.
Intense sunlight can lead to development of skin cancers. People with little or no melanin in their eyes, skin, or hair are called albinos. If an albino child shows unusual bruising or bleeding one may suspect Hermansky-Pudlak syndrome. Skin passively protects the body from elements of nature and microbes. It is now known that epidermal cells called Langerhans cells trap antigens penetrating skin.