Edward Bagnall Poulton

Sir Edward Bagnall Poulton (January 27 1856–November 20 1943) was a British evolutionary zoologist. He became Hope Professor of Zoology at the University of Oxford in 1893.

Life

Between 1873 and 1876, he 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. [cite web|url=http://www.oxforddnb.com/view/article/35586| title=Poulton, Sir Edward Bagnall (1856–1943)|last=Carpenter |first=G. D. H |work=Oxford Dictionary of National Biography (online) (subscription access) |publisher=Oxford University Press|accessdate=2007-07-18] 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 known as a generous benefactor to the college, providing silver for the high table and redecorating the Old Bursary amongst other donations. [ cite book|last=Baker|first= J. N. L. |date=1971| title=Jesus College 1571 – 1971|pages=68]

Family

Poulton's son, Ronald Poulton-Palmer played international rugby for England and was killed in World War I. His daughter, Janet Palmer, married Charles Symonds in 1915 and died in 1919. [cite web|first=Ian|last=Mackenzie|title=‘Symonds, Sir Charles Putnam (1890–1978)’|coauthors=rev.|work=Oxford Dictionary of National Biography|publisher=Oxford University Press|year=2004|url=http://www.oxforddnb.com/view/article/31744|accessdate=2008-06-11|doi=10.1093/ref:odnb/31744|format=subscription required]

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 in species formation.

In his 1896 work on Darwin, 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 in his day. 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. [Bowler P.J. 1983. "The eclipse of Darwinism: anti-Darwinian evolutionary theories in the decades around 1900". Johns Hopkins, Baltimore.] 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::1. The absence of transitional forms and the frequent lack of mimicry in male butterflies were unexplained by selectionist theory. :2. The enigma of polymorphic mimicry. Some species of butterfly mimicked not merely one, but several models. In breeding experiments these polymorphs cleanly segregated according to Mendel’s law of segregation. :3. Evidence of birds as selective agents was slight and little was known of birds' discriminatory powers, and:4. The gradual accumulation of minute variations did not fit with the facts of heredity.

For Punnett, none of these observations were explained by gradual selectionism. Instead the evidence suggested that mimicry had arisen from sudden mutational jumps (saltations). Once a mimic was formed by mutation, natural selection might play a conservative role.

However, one by one, each of these objections were shown to be without substance. Evidence that predatory birds were the agents in many cases of selection in insects was steadily produced by field observations and experiments. [Carpenter G.D.H. and E.B. Ford 1933. "Mimicry". Methuen, London] [Brower L.P. 1988. "Mimicry and the evolutionary process". Chicago.] [Endler J.A. 1986. "Natural selection in the wild". Princeton.] Evidence that small-scale mutations were common arrived as soon as breeding experiments were designed to detect them: it was a consequence of experimental methods that early mutations were so noteworthy. The question of polymorphism is discussed in polymorphism (biology).

The gradual coming-together of field observations and experimental genetics is part of the evolutionary synthesis which took place in the middle of the twentieth century. [Huxley, J.S. "Evolution: the modern synthesis", Allen and Unwin, 1942] As is now obvious, mutations increase the amount of heritable variation in a population, and selection is how we describe the differential viability of those variants. [Maynard Smith J. 1998. "Evolutionary genetics". 2nd ed, Oxford.] Poulton's account is much closer to our present-day view of evolution, but Punnett was right to ask his difficult questions. This interesting field of research is still quite active. [Ruxton G.D., Sherratt T.N. & Speed M.P. 2004. "Avoiding attack: the evolutionary ecology of crypsis, warning signals and mimicry". Oxford.] [Gilbert, Francis. 2004. The evolution of imperfect mimicry in hoverflies. In Fellows M., Holloway G. and Rolff J (eds) "Insect evolutionary biology".]

Poulton's Presidential Address to the British Association in 1937 at the age of 81 reviewed the history of evolutionary thought. The work of J.B.S. Haldane, R.A. Fisher and Julian Huxley was vitally important for showing the relationships between Mendelism and natural selection. The observations and experiments of many biologists had "immensely strengthened and confirmed" the researches on mimicry and warning colours of pioneers like Bates, Wallace, Meldola, Trimen and Müller.

Awards and honours

*Awarded the Royal Society's Darwin Medal in 1914
*Awarded the Linnean Society's Linnean Medal in 1922.
*Knighted in 1935. [LondonGazette|issue=34119|supp=yes|startpage=1|endpage=2|date=28 December 1934|accessdate=2008-06-11
LondonGazette|issue=34135|startpage=1269|date=22 February 1935|accessdate=2008-06-11]
*President of the British Association for the Advancement of Science (BAAS) for 1937.

Works

Poulton had over 200 publication spanning over sixty years. His most widely known work was probably "The Colours of Animals".

Published works

* Poulton E.B. 1890. "The colours of animals: their meaning and use, especially considered in the case of insects". Kegan Paul, London.
* Poulton E.B. "Charles Darwin and the theory of natural selection". 1896.
* Poulton E.B 1904. What is a species? (Presidential address to the Entomological Society of London, Jan 1904) "Proc. Ent. Soc. Lond. 1903"
* Poulton, E.B. 1908. "Essays on evolution". London, Cassell.
* Poulton, E.B. 1915. "Science and the Great War: The Romanes Lecture for 1915" Clarendon Press, Oxford.

Legacy

Poulton is remembered as an early originator of the biological species concept. [Mallet, J. (2004). Poulton, Wallace and Jordan: how discoveries in "Papilio" butterflies initiated a new species concept 100 years ago. "Systematics and Biodiversity, 1"(4): 441–452.] He invented the term aposematism for warning coloration and advocated experimental tests of mimicry theory.

ee also

*Animal colouration
*Aposematism
*Frequency dependent selection
*Polymorphism (biology)
*Alfred Russel Wallace

References

External links

* [http://www.ucl.ac.uk/taxome/jim/Mim/poulton.html Brief biography]
* [http://faculty.kirkwood.edu/ryost/poulton.htm Biography]
* Mallet, J. (2004). Poulton, Wallace and Jordan: how discoveries in "Papilio" butterflies initiated a new species concept 100 years ago. "Systematics and Biodiversity, 1"(4): 441–452. [http://www.ucl.ac.uk/taxome/jim/pap/malletsystbiodiv04.pdf pdf] .