DE BEER, GAVIN RYLANDS

(b. Malden, Surrey, England, 1 November 1899; d. Alfriston, Sussex, England, 21 June 1972)

zoology, embryology, evolution.

De Beer was the son of Herbert Chaplin de Beer and Mabel Chaplin Rylands de Beer, whose mothers were first cousins. Soon after Gavin’s birth his peripatetic father moved the family to Paris, where he was correspondent of the Exchange Telegraph Company. De Beer thus grew up and went to school in Paris and Versailles. He owed to this experience his exceptional linguistic ability, for he was bilingual in French and English and fluent in Swiss German and Italian. After his schooling in France, he enrolled at Harrow, where he was attracted to zoology. After graduating from Harrow, he entered Magdalen College, Oxford, in 1917, but remained for only a term. De Beer served in the British Army during World War I, and in 1919 he returned to Magdalen to read zoology. After graduation in 1922, he remained at Oxford to teach and do research in zoology; in 1923 he was elected fellow of Merton College, where he stayed until 1938. On 2 March 1925 he married Cicely Glyn Medlycott.

De Beer’s earliest research followed in the footsteps of Julian Huxley, then the most influential teacher of zoology at Oxford. Like Huxley, De Beer would dabble on the edges of experimental embryology without becoming deeply involved. He performed simple experiments; he visited Hans Spemann at Freiburg to learn the techniques of operating on embryos; and he published a series of synoptic embryological and zoological texts (Growth, 1924; An Introduction to Experimental Embryology, 1926; Vertebrate Zoology, 1928). His two works of most enduring importance appeared in the early 1930’s. The earlier is his best-known work. Embryology and Evolution (1930; titled Embryos and Ancestors in later editions). It is a short, controversial, and influential assault on the theory of recapitulation. That theory, according to which the successive developmental stages of an individual represent the successive adult ancestral stages in the phylogeny of the species, was then no longer widely accepted by biologists, But its influence persisted, both among a reactionary minority of biologists (such as the anti-Mendelian Ernest William MacBride) and especially among those unfamiliar with the latest trends of biological thought. De Beer wrote Embryology and Evolution to make naive recapitulationism inexcusable, and in this he was highly successful.

In the theory of recapitulation, there is only one kind of relation between embryology and evolution. All evolutionary change takes place by adding new evolutionary stages to the end of the animal’s ontogeny, through modification of the adult stage. De Beer, following Walter Garstang and others, maintained that the real relation of development and evolution is much broader. Any stage of the life cycle can be modified; evolution can take place by altering the relative rates of development of different organs, at any stage in development. De Beer could improve on Garstang by giving a genetic account of the process. In 1927 Huxley and Edmund B. Ford discovered the Mendelian rate-genes affecting eye color in the amphipod Gammarus: different alleles caused melanin pigment to be laid down at different rates, according to the ambient temperature. This was not the first discovery of rate-genes— Richard B. Goldschmidt had priority—but it was the Gammarus work that influenced the Oxford zoologists. There it was widely realized—by Huxley, Ford, and J. B. S. Haldane, as well as by De Beer— that changes in rate-genes could cause changes in the time at which different organs developed. For instance, if a rate-gene speeded up the timing of sexual maturity, organs characteristic of larval stages would become adult organs and would stand the process of recapitulation on its head. In De Beer’s account, evolutionary changes could take place through the speeding up or the slowing down of the development of organs at any stage. Comparisons among species seemed to demand this kind of general relationship rather than the particular one in the theory of recapitulation. De Beer classified the various possible relations of embryonic and evolutionary changes.

The Elements of Experimental Embryology (1934), De Beer’s other well-known book, was concerned not with the phylogeny of species but with the causes of development. Whereas Embryology and Evolution was a short polemic, Elements was a long synthesis. Written with Huxley, it interprets development in terms of the gradient theory of positional information of Charles M. Child, of which Huxley had always been an enthusiast. It is no longer thought that development can be explained only in those terms, but Huxley and De Beer’s remains the classic attempt.

Elements represents the end of one phase in De Beer’s career; Embryology and Evolution, the beginning of another. In the 1920’s he had been interested mainly in causal and descriptive embryology; now he would become increasingly interested in comparative and phylogenetic embryology. He embarked on a major project: describing the development of the skull and head of the main vertebrate groups. It resulted in a large work, The Development of the Vertebrate Skull (1937), which he intended to serve as a solid descriptive basis for subsequent analytical work. As with most attempts to provide solid descriptive bases, not much use has been made of it.

In 1938 De Beer moved to London, as reader in embryology at University College, London. His work was interrupted by World War II, during which he again served in the British Army; after the war he became increasingly involved with administration. He was elected fellow of the Royal Society in 1940 and was knighted in 1954. He was professor of embryology at University College, London, from 1946 to 1950, and then became director of the British Museum (Natural History) from 1950 to 1960. In 1958 he organized the celebrations of the DarwinWallace centenary. His most important zoological contribution during the 1950’s was his descriptive morphological monograph Archaeopteryx lithographica (1954).

De Beer retired from full-time zoological work in 1960. He then became interested in Darwinian scholarship, editing and publishing the transmutation notebooks. He also wrote a biography, Charles Darwin (1963). Another work was his splendidly illustrated Atlas of Evolution (1964), a pioneer in the medium of large-format, color-illustrated works. He continued writing after moving to Switzerland in 1965; in 1972 he returned to England, where he died of a heart attack.

De Beer was a widely read man. He wrote books on a remarkable range of subjects—on travelers in the Alps, the route of Hannibal’s passage, and the lives of Sir Hans Sloane, Gibbon, and Rousseau— as well as works on evolution, all in a pure, clear prose. Many of his books continued to be reprinted long after his death.

BIBLIOGRAPHY

I. Original Works. De Beer’s most important biological works are The Comparative Anatomy, Histology and Development of the Pituitary Body (London, 1926); Embryology and Evolution (Oxford, 1930); The Elements of Experimental Embryology (Cambridge, 1934; repr. 1963), with Julian Huxley; The Development of the Vertebrate Skull (Oxford, 1937); Archaeopteryx lithographica (London, 1954); Charles Darwin (London and Garden City, N.Y., 1963); and Atlas of Evolution (London, 1964).

II. Secondary Literature. E. J. W. Barrington, “Gavin Rylands de Beer,” in Biographical Memoirs of Fellows of the Royal Society of London, 19 (1973), 65–93, with an extensive bibliography: Stephen Jay Gould, Ontogeny and Phylogeny (Cambridge, Mass., 1977); Mark Ridley, “Embryology and Classical Zoology in Great Britain,” in T. J. Horder. J. H. Witkowski, and C. C. Wylie, eds., A History of Embryology (Cambridge, 1986), 35–67.

Mark Ridley