Composite of original line drawings from Darwin’s “Variation in Animals and Plants under Domestication” 1868. The ancestral form, the rock pigeon hangs up dead to the left. Some of the many varieties produced from it by artificial selection (selective breeding for traits) are shown to the right. Darwin saw natural selection as operating like a human breeder to favour those individuals whose traits best suited them for reproduction in the prevailing conditions. Darwin himself bred pigeons from 1855 and became very familiar with the literature, types, and other breeders. He joined two of the London pigeon clubs and noted that behaviour, as well as appearance, could be selected. The tumbler bottom right being a case in point. He also believed that an ornithologist faced with any of these varieties in the wild would not hesitate to make them a different species from the ancestral stock.