Sir Edward Bagnall Poulton, FRS HFRSE FLS (27 January 1856 – 20 November 1943) was a British evolutionary biologist, a lifelong advocate of natural selection through a period in which many scientists such as Reginald Punnett doubted its importance. He invented the term sympatric for evolution of species in the same place, and in his book The Colours of Animals (1890) was the first to recognise frequency-dependent selection. Poulton is also remembered for his pioneering work on animal coloration. He is credited with inventing the term aposematism for warning coloration, as well as for his experiments on 'protective coloration' (camouflage). Poulton became Hope Professor of Zoology at the University of Oxford in 1893.
Life
Edward Poulton was born in Reading, Berkshire on 27 January 1856 the son of the architect William Ford Poulton and his wife, Georgina Sabrina Bagnall. He was educated at Oakley House School in Reading.
Between 1873 and 1876, Poulton studied at Jesus College, Oxford under George Rolleston and the anti-Darwinian entomologist John Obadiah Westwood, graduating with a first-class degree in natural science. He maintained an unbroken connection with the college for seventy years as scholar, lecturer and Fellow (appointed to a fellowship in 1898) until his death. He was a generous benefactor to Jesus College, providing silver for the high table and redecorating the Old Bursary amongst other donations.
He was knighted by King George V in 1935. Poulton died in Oxford on 20 November 1943.
Career
Poulton was throughout his career a Darwinist, believing in natural selection as the primary force in evolution. He not only admired Charles Darwin, but also defended the father of neo-Darwinism, August Weismann. Poulton was one of the group of biologists who first translated Weismann's work into English, and he defended Weismann's idea of the continuity of the germ-plasm. In the course of these translations, he noted that recent researches had reduced or perhaps entirely removed the role of acquired characters (Lamarckism) in species formation.
His 1890 book, The Colours of Animals, introduced the concepts of frequency-dependent selection and aposematic coloration, as well as supporting Darwin's then unpopular theories of natural selection and sexual selection. He conducted a range of experiments on the colours of polymorphic caterpillars to examine if food, background or other factors are involved in their colour changes. He was able to show that the caterpillars were sensitive to the background colours and that it was perceived even when they were blinded, and was among the earliest to suggest extraocular photoreception.
Poulton enlarged the Hope entomological collections with his catches in the field which earned him the nickname of "Bag-all" Poulton. Many of the specimens are unmounted and held in biscuit tins (possibly acquired through Huntley & Palmer biscuits owned by his wife's family).
In his 1896 book Charles Darwin and the Theory of Natural Selection, Poulton described the Origin of Species as "incomparably the greatest work" the biological sciences had seen. Critics of natural selection, Poulton contended, had not taken the time to understand it. This is an evaluation which is much more widely held today than it was then, during the so-called eclipse of Darwinism. The contemporary ignorance of the mechanism of inheritance stood in the way of a full understanding of the mechanism of evolution.
In 1897 Poulton canvassed members during meetings of the Entomological Society of London. He discovered that many doubted a selectionist origin for mimicry. Of those he asked, only three fully supported Batesian mimicry and Müllerian mimicry. The others doubted the inedibility/unpalatability of the models (some investigators even performed taste tests!) or were not convinced that birds were effective selective agents. External and internal forces remained popular alternatives to natural selection.
The arrival of genetics
The rediscovery of Mendel's work filled a critical gap in evolution theory, but at first this was not realised, and many thought it antithetical to selection. There was a long debate between Poulton and Reginald Punnett, one of Bateson's disciples and the first Professor of Genetics at Oxford. Punnett's Mimicry in butterflies (1915) rejected selection as the main cause of mimicry. He noted: