Why do people have different skin colours?
Production of skin pigment (melanin, the same pigment that makes eyes and hair brown) is under genetic control. Melanin protects the body from damage by UV light. The proto-human line first appeared in tropical Africa about 2.5 million years ago, evolving from a genetic heritage that has also led to chimps and gorillas. Since our forebears came from a very high-UV environment, individuals who had a genetic tendency to produce insufficient melanin would suffer health consequences (e.g. baaad sunburn, sun-blindness, free radical damage, and possibly also cancers) which made them less able to survive and reproduce. Thus, high melanisation became the ‘default’ option in our genetic code. ‘Modern’ humans first appeared about 250,000 years ago, and started migrating out of Africa relatively recently (in geological terms)–between 100,000 and 50,000 years ago, depending on whose theory you follow. Geological and archaeological evidence shows that the most likely route would have been into wha
