page_title: Coloration evidence for natural selection
section_title: Müllerian
hierarchical_section_title: Coloration evidence for natural selection / Mimicry / Müllerian
caption_attribution_description: Yellow-banded Poison Dart frog Dendrobates leucomelas at Bristol Zoo, Bristol, England. Photographed by Adrian Pingstone in May 2005 and released to the public domain.
context_page_description: Animal coloration provided important early evidence for evolution by natural selection, at a time when little direct evidence was available. Three major functions of coloration were discovered in the second half of the 19th century, and subsequently used as evidence of selection: camouflage; mimicry, both Batesian and Müllerian; and aposematism.
  Charles Darwin's On the Origin of Species was published in 1859, arguing from circumstantial evidence that selection by human breeders could produce change, and that since there was clearly a struggle for existence, that natural selection must be taking place. But he lacked an explanation either for genetic variation or for heredity, both essential to the theory. Many alternative theories were accordingly considered by biologists, threatening to undermine Darwinian evolution.
  Some of the first evidence was provided by Darwin's contemporaries, the naturalists Henry Walter Bates and Fritz Müller. They described forms of mimicry that now carry their names, based on their observations of tropical butterflies.
context_section_description: Müllerian mimicry, too, in which two or more distasteful species that share one or more predators have come to mimic each other's warning signals, was clearly adaptive; Fritz Müller described the effect in 1879, in an account notable for being the first use of a mathematical argument in evolutionary ecology to show how powerful the effect of natural selection would be.
caption: Warning coloration protects poison dart frog Dendrobates leucomelas.
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