Some Biogeographers, Evolutionists and Ecologists:
Chrono-Biographical Sketches

Willis, John Christopher (England 1868-1958)
botany, phytogeography, evolutionary biology

Willis's early botanical work revealed an excellent observer who excelled not only in morphological studies on both living and fossil plant forms, but also in compilations and literary synthesis. An accident in 1905 pushed him even further in the latter directions. He began to investigate patterns of geographic range within large taxa and, in the words of his Royal Society obituary, came up with "the working hypothesis...that the range of a taxon depends on the age of the taxon and conversely that range gives a clear indication of age. The word taxon is used because, though Willis first applied age and area to species, he later extended it to genera and families." Willis first presented his "age and area" theory in detail in a 1915 work on the endemic plant species of Ceylon, and published his definitive treatment of the concept in the book Age and Area in 1922. Willis's data were on the whole unconvincing, as was his abandonment of natural selection principles in favor of an evolutionary process driven by major mutation events (extending ideas first presented some years earlier by Guppy); the combined effect was the posing of a process in which large taxa evolved first and then split up into smaller taxa through episodes of mutation-occasioned divergence. The "age and area" theory attracted some interest for about twenty years, but support for it was clearly on the wane by the time of Willis's late books The Course of Evolution and The Birth and Spread of Plants (though each of these works contained some interesting ideas).

Life Chronology

--born in Birkenhead, England, on 20 February 1868.
--educated at University College, Liverpool, and at Cambridge University
--1894-1896: assistant and lecturer in botany at Glasgow University
--1896-1911: director of the Royal Botanical Gardens, Ceylon
--1897: made a member of the Linnean Society of London
--1897: publishes the first edition of his A Manual and Dictionary of the Flowering Plants and Ferns, in two volumes
--1901: founds the Annals of the Royal Botanic Gardens
--1905: an accident affecting his eyesight causes him to turn to study of the literature of plant distribution
--1912-1915: director of the Botanic Garden, Rio de Janeiro
--1915: publishes "The Endemic Flora of Ceylon, With Reference to Geographical Distribution and Evolution in General" in the Philosophical Transactions of the Royal Society of London, Series B
--1919: made a fellow of the Royal Society of London
--1922: publishes his Age and Area; A Study in Geographical Distribution and Origin of Species
--1924-1939: editor of The Empire Cotton Growing Review
--1940: publishes his The Course of Evolution by Differentiation or Divergent Mutation Rather Than by Selection
--1949: publishes his The Birth and Spread of Plants
--1958: honored with the Linnean Society's Darwin-Wallace medal
--dies at Montreux, Switzerland, on 21 March 1958.

For Additional Information, See:

--Biographical Memoirs of Fellows of the Royal Society, Vol. 4 (1958): 353-359.
--Proceedings of the Linnean Society of London, Vol. 169 (1958): 245-250.
--Taxonomic Literature, Vol. 7 (1988).

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Copyright 2005 by Charles H. Smith. All rights reserved.

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