Human skin color Human skin color Human skin color ranges in variety from the darkest brown to the lightest hues. An individual's skin pigmentation is the result of genetics, being the product of both of the individual's biological parents' genetic makeup, and exposure to sun. In evolution, skin pigmentation in human beings evolved by a process of natural selection primarily to regulate the amount of ultraviolet radiation penetrating the skin, controlling its biochemical effects. The actual skin color of different humans is affected by many substances, although the single most important substance is the pigment melanin. Melanin is produced within the skin in
What Bird is That? of "What Bird is That?" It was published in 1984 and incorporated all of Cayley’s paintings created over many years for his vision of releasing a “big bird book” and included a revised taxonomy. In the 53 years since its first edition, more than a hundred new bird species had been identified in Australia. Scientific names had been changed and groups of birds had been reordered. Lindsey brought "What Bird is That?" up-to-date with the latest birding conventions of the time, as well as contributing a valuable supplementary list of birds and a scholarly catalogue of Cayley’s paintings. The "Signature