Animals
It is believed that the American Robin practices assortative mating on plumage color, a melanin based trait. However, in female American Robins, dark plumage indicates reproductive performance, while dark plumage in males indicates health and decreased parental investment. Nevertheless, positive assortment based on plumage color may explain the American Robin’s unique mating pattern of remaining together throughout the breeding season but never reuniting in subsequent breeding seasons. Because assortative mating based on plumage color adequately predicts reproductive success, there are higher levels of fidelity and less need for extra pair relations.
Positive assortative mating is believed to be the cause of the speciation of a daughter species from the parent species of coral-dwelling goby fish. The species live in a small area of rare coral in the ocean around Bootless Bay in southern Papua New Guinea which the parent species shun. The daughter species has become reproductively isolated from the parent species even though the parent species surrounds the daughter species so there is no geographic isolation. The speciation in the early stages would depend on assortative mating in which the evolving goby fishes would prefer to mate with other fish that preferred to spawn in the same area of rare coral.
Read more about this topic: Assortative Mating
Famous quotes containing the word animals:
“We know what the animals do, what are the needs of the beaver, the bear, the salmon, and other creatures, because long ago men married them and acquired this knowledge from their animal wives. Today the priests say we lie, but we know better.”
—native American belief, quoted by D. Jenness in “The Carrier Indians of the Bulkley River,” Bulletin no. 133, Bureau of American Ethnology (1943)
“There is nothing worse than an idle hour, with no occupation offering. People who have many such hours are simply animals waiting docilely for death. We all come to that state soon or late. It is the curse of senility.”
—H.L. (Henry Lewis)
“Researchers, with science as their authority, will be able to cut [animals] up, alive, into small pieces, drop them from a great height to see if they are shattered by the fall, or deprive them of sleep for sixteen days and nights continuously for the purposes of an iniquitous monograph.... “Animal trust, undeserved faith, when at last will you turn away from us? Shall we never tire of deceiving, betraying, tormenting animals before they cease to trust us?””
—Colette [Sidonie Gabrielle Colette] (1873–1954)