“The Gloger rule states that in warm-blooded higher animals the melanin pigmentation tends to grow with a. Heat and humidity. A high degree of moisture, combined with a high degree of heat causes black pigmentation. The maximum pigmentation being in the warm regions of the equator and the minimum at the Arctic Circle. The same scale seems to be valid for man.”
Source: Cheikh Anta Diop. “Pigmentation des anciens Égyptiens. Test par la mélanine.” Bulletin of the Fundamental Institute for Black Africa. Volume XXXV, No. 3. July 3, 1973. Translated by Keyamsha. https://keyamsha.com/2017/04/10/the-melanin-dosage-test-by-cheikh-anta-diop/.
