gene, which signals melanocytes to produce eumelanin instead of pheomelanin.
: Dark hair results from high levels of eumelanin produced by melanocytes in the hair follicle bulb. 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 gene, which signals melanocytes to produce eumelanin instead