Dark Hair -

: Pigment synthesis begins with the amino acid L-tyrosine , which is converted by the enzyme tyrosinase into dopaquinone. In the absence of high sulfur levels (cysteine), this precursor polymerizes into the dark eumelanin. Evolutionary Context

: Dark hair results from high levels of eumelanin produced by melanocytes in the hair follicle bulb. dark hair

: Most individuals with dark hair possess two functional copies of the MC1Rcap M cap C 1 cap R : Pigment synthesis begins with the amino acid

The color of human hair is determined by the concentration and ratio of two types of melanin: (brown-black) and pheomelanin (red-yellow). dark hair