Pigmentation in plants and animals come from compounds called melanin. Humans get their coloring from three melanin compounds: brown eumelanin, black eumelanin, and pheomelanin.
Those who can produce black eumelanin generally have black hair. Production of this compound begins at birth so these babies have the same color of hair until they grow old.
Most people from Europe and northern Russia can't produce black eumelanin. For these people hair color is mostly determined by brown eumelanin levels. The more of it you have in your hair, the darker it will be. Blonde hair contains little eumelanin while brown hair has a lot.
Pheomelanin gives hair a redish color. However, eumelanin covers pheomelanin. To have red hair one needs to have both high levels of pheomelanin and low levels of eumelanin.
Brown eumelanin production is low during infancy, increasing to average lifetime levels in early childhood. As a result, a baby may have blonde or red hair depending on pheomelanin levels. Once eumalinin production kicks in the hair darkens until it becomes his or her adult color.
Posted 4446 day ago