Gloger's Rule: Human skin pigmentation

    Gloger's Rule states that darkness of skin or pelage (measurable as low reflectance) is correlated with humid environments, which tend to occur in equatorial zones. Humans (Homo sapiens) are darker in humid tropical environments, and lighter in drier northern and southern temperate environments. Gloger's rule is overlaid on the evolutionary origin of Homo in Africa: darker skin in the Neotropics in a secondary darkening following a lightening after migration "Out of Africa" roughly 70,000 years ago into the Palearctic, and migration to the New World roughly 20,000 years ago. The gallery below is graded on the Pantone scale used to describe skin tone for photography.