Edward Bagnall Poulton

Sir Edward Bagnall Poulton, FRS[1] 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.[2]

Sir Edward Bagnall Poulton
Sir Edward Bagnall Poulton
Photograph by James Lafayette
Born(1856-01-27)27 January 1856
Died20 November 1943(1943-11-20) (aged 87)
NationalityEnglish
Alma materJesus College, Oxford
Known forAposematism, frequency-dependent selection, camouflage
AwardsLinnean Medal (1922)
Hope Professor of Zoology
Scientific career
FieldsEvolutionary biology
InstitutionsUniversity of Oxford

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.[3]

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.[4] 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.[5]

He was knighted by King George V in 1935. Poulton died in Oxford on 20 November 1943.

Career

First edition of The Colours of Animals, 1890, introduced a set of new terms for animal coloration including "aposematic".

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.[6] 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.[7]

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).[8]

In his 1896 book Charles Darwin and the Theory of Natural Selection,[9] 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.[10] 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 (in his view) fit with the facts of heredity.

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

Warning coloration of the "Brazilian Skunk" in The Colours of Animals: Poulton introduced the term aposematism in the book.

However, one by one, each of these objections was shown to be without substance. Evidence from field observations and experiments showed that birds were often the agents of selection in insects.[11][12][13] 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. Explanations for polymorphism were advanced by E.B. Ford, Theodosius Dobzhansky and their colleagues, who developed experimental methods for populations in the wild.[14][15]

The gradual coming-together of field observations and experimental genetics is part of the modern synthesis which took place in the middle of the twentieth century.[16] As has become widely accepted, mutations increase the amount of heritable variation in a population, and selection is how biologists describe the differential viability of those variants.[17] Poulton's account is much closer to a modern view of evolution, though Punnett had framed important questions.[18][19]

Poulton's Presidential Address to the British Association in 1937 at the age of 81 reviewed the history of evolutionary thought. He stated that 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.[20]

Family

Poulton with the Entomological Society in 1904 (sitting, centre)

Poulton lived with his family at 56 Banbury Road in North Oxford, a large Victorian Gothic house designed by John Gibbs and built in 1866.[21]

In 1881 he married Emily Palmer (d.1939), daughter of George Palmer, M.P. for Reading and head of Huntley and Palmer's biscuit company; they had five children. Three of them were dead by 1919. Their eldest son Dr. Edward Palmer Poulton of Guy's Hospital died in 1939, meaning that Sir Edward was outlived only by his daughter Margaret Lucy (1887–1965), wife of Dr Maxwell Garnett. Poulton's son, Ronald Poulton-Palmer played international rugby for England and was killed in May 1915 in World War I. His first daughter Hilda married Dr Ernest Ainsley-Walker and died in 1917. His youngest daughter, Janet Palmer, married Charles Symonds in 1915 and died in 1919.[22]

Legacy

Poulton is remembered as an early originator of the biological species concept.[23][24][25] According to Ernst Mayr, Poulton invented the term sympatric in relation to species,[26] and he also invented the term aposematism for warning coloration.

Poulton, along with Julian Huxley, J.B.S. Haldane, R.A. Fisher and E.B. Ford, promoted the idea of natural selection through many years when it was denigrated.[10]

Poulton was succeeded by G.D. Hale Carpenter as Hope Professor of Entomology at Oxford University from 1933 to 1948.[27]

Published works

Poulton had over 200 publications spanning over sixty years.

Awards and honours

See also

References

  1. Carpenter, G. D. H. (1944). "Edward Bagnall Poulton. 1856–1943". Obituary Notices of Fellows of the Royal Society. 4 (13): 655–680. doi:10.1098/rsbm.1944.0014.
  2. "POULTON, Edward Bagnall". Who's Who. Vol. 59. 1907. p. 1421.
  3. Biographical Index of Former Fellows of the Royal Society of Edinburgh 1783–2002 (PDF). The Royal Society of Edinburgh. July 2006. ISBN 0-902-198-84-X. Archived from the original (PDF) on 4 March 2016. Retrieved 14 January 2018.
  4. Carpenter, G. D. H. "Poulton, Sir Edward Bagnall (1856–1943)". Oxford Dictionary of National Biography (online, free). Oxford University Press. Retrieved 18 July 2007.
  5. Baker, J.N.L. (1971). Jesus College 1571 – 1971. p. 68.
  6. Mallet, Jim. "E.B. Poulton (1890)". University College London. Retrieved 23 November 2012.
  7. Poulton, E.B. (1892). "Further experiments upon the colour-relation between certain lepidopterous larvae, pupae, cocoons, and imagines and their surroundings". Transactions of the Royal Entomological Society of London. 40: 293–487.
  8. Salmon, Michael A. (2000). The Aurelian Legacy. Harley Books. pp. 187–188.
  9. Poulton E.B. Charles Darwin and the theory of natural selection. 1896.
  10. Bowler, Peter J. (1983). The Eclipse of Darwinism: anti-Darwinian evolutionary theories in the decades around 1900. Johns Hopkins University Press. ISBN 978-0-8018-4391-4.
  11. Carpenter, G. D. Hale; Ford, E. B. (1933). Mimicry. London: Methuen.
  12. Brower, L. P., ed. (1988). Mimicry and the evolutionary process. Chicago: University of Chicago Press. ISBN 0-226-07608-3.
  13. Endler J.A. 1986. Natural selection in the wild. Princeton.
  14. Ford, E. B. (1975) [1964]. Ecological genetics (4th ed.). London: Chapman and Hall.
  15. Dobzhansky, Theodosius (1970). Genetics of the Evolutionary Process. New York: Columbia University Press. ISBN 978-0-231-02837-0. LCCN 72127363. OCLC 97663.
  16. Huxley, J.S. Evolution: the modern synthesis, Allen and Unwin, 1942
  17. Maynard Smith J. 1998. Evolutionary genetics. 2nd ed, Oxford.
  18. Ruxton G.D., Sherratt T.N. & Speed M.P. 2004. Avoiding attack: the evolutionary ecology of crypsis, warning signals and mimicry. Oxford.
  19. Gilbert, Francis. 2004. The evolution of imperfect mimicry in hoverflies. In Fellows M., Holloway G. and Rolff J (eds) Insect Evolutionary Biology.
  20. Poulton, E. B. (September 1937). "BRITISH ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE. Nottingham, 1937. THE PRESIDENTIAL ADDRESS. THE HISTORY OF EVOLUTIONARY THOUGHT". Current Science. 6 (3): 105–118. JSTOR 24204999.
  21. Hinchcliffe, Tanis (1992). North Oxford. New Haven & London: Yale University Press. p. 105. ISBN 978-0-14-071045-8.
  22. "Symonds, Sir Charles Putnam (1890–1978)". Oxford Dictionary of National Biography (online ed.). Oxford University Press. doi:10.1093/ref:odnb/31744. Retrieved 11 June 2008. (Subscription or UK public library membership required.)
  23. Poulton E.B. 1904. What is a species? (Presidential address to the Entomological Society of London) Proc. Ent. Soc. Lond. (revised version in Poulton E.B. Essays on Evolution. 1889–1907. Clarendon Press, Oxford. p46–94)
  24. Poulton E.B. 1938. The conception of species as interbreeding communities. Proceedings of the Linnean Society of London. p225–226
  25. Mallet, James (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. doi:10.1017/s1477200003001300. S2CID 86041887.
  26. Mayr, Ernst (1942). Systematics and origin of species. New York: Columbia University Press. p. 148.
  27. Remington, Charles L. 1954. Lepidopterist's News, 8, p31-43.
  28. Meldola, R. (25 November 1909). "Review of Charles Darwin and the Origin of species; addresses, etc., in America and England in the year of the two anniversaries by Prof. E. B. Poulton". Nature. 82 (2091): 91–93. doi:10.1038/082091a0. S2CID 26879402.
  29. "Lists of Royal Society Fellows 1660–2007". London: The Royal Society. Archived from the original on 24 March 2010. Retrieved 14 July 2010.
  30. "No. 34119". The London Gazette (Supplement). 28 December 1934. pp. 1–2.
    "No. 34135". The London Gazette. 22 February 1935. p. 1269.
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