This article was published in Australian Dictionary of Biography, Volume 15, (MUP), 2000
Alexander John Nicholson (1895-1969), entomologist, was born on 25 March 1895 at Blackhall, near Dunboyne, County Meath, Ireland, second of four children of Alexander Nicholson, draughtsman, and his wife Agnes Hannah, née Smith. The family moved to Birmingham, England, where in 1908 John entered Waverley Road Secondary School and joined the Birmingham Field Naturalists' Club. He graduated from the University of Birmingham (B.Sc., 1915; M.Sc., 1920) with first-class honours in zoology. Commissioned on 3 November 1915 in the Royal Field Artillery, he served in France and Belgium with the Royal Regiment of Artillery; he was twice mentioned in dispatches and received King George V's commendation for bravery.
In 1919 Nicholson returned to the University of Birmingham and carried out research on the development of the ovaries in the mosquito, Anopheles maculipennis. Appointed first McCaughey lecturer in entomology at the University of Sydney, he visited teaching and research institutions in the United States of America before arriving in Australia in October 1921. Over the next eight years he produced graduates in agriculture who took a broad, 'new approach to economic entomology'. He rapidly acquired a wide knowledge of Australian insects, built up a notable teaching collection, and took many photographs using a telescopic rangefinder which he had developed to sharpen close shots.
The photographs provided a valuable basis for 'A New Theory of Mimicry in Insects', Nicholson's presidential address in 1927 to the Royal Zoological Society of New South Wales; published that year in the Australian Zoologist, it was a major work for which the University of Sydney awarded him a D.Sc. (1929). The article gave a comprehensive account of Australian insects' capacity for mimicry and concealment, outlined basic principles and hypotheses, and foreshadowed his main research interests thereafter. His central thesis was that 'animal populations could not survive in nature unless their densities were governed by a regulatory (feed-back) mechanism that was density-dependent in its operation'.
Nicholson used arithmetical models to explore his ideas further, and collaborated with V. A. Bailey who provided a more rigorous mathematical treatment which confirmed his approximations. In 1933 Nicholson published a classical paper, 'The Balance of Animal Populations' in the Journal of Animal Ecology in which he showed that populations characteristically fluctuated and generally about a mean density. Balance, in this context, was akin to the outcome of the compensatory movements of a tightrope walker, rather than the steady state assumed by a chemical equilibrium.
The Council for Scientific and Industrial Research's division of economic entomology (Commonwealth Scientific and Industrial Research Organization's division of entomology, from 1949) was established in 1928 with R. J. Tillyard as its first chief. Next year 'Nic' (as Nicholson was by then known) was offered the post of deputy-chief. He began work in Canberra in 1930. Finding that the scientifically distinguished Tillyard was an inept administrator, he requested a transfer to sheep-blowfly investigations and devised ingenious ways to use traps for measuring the efficiency of baits. In 1933 Nicholson became acting-chief. At St Paul's Anglican Church, Kyneton, Victoria, on 28 October that year he married Phyllis Heather Jarrett, a 28-year-old plant pathologist.
Under Nicholson the activities of the division grew steadily in scope and reputation, a judicious balance being maintained between fundamental and applied research. He was a meticulous worker, but took considerable time to develop proposals and to react to memoranda. This irritated C.S.I.R. executives, though they came to respect (even to admire) the clarity and scientific integrity of his advice. On 16 April 1936 he was appointed chief. Biological control and taxonomy remained major divisional activities, but ecology attained equal importance, and studies in physiology, biochemistry and toxicology were added. The scientific staff increased: 16 in 1933, 23 in 1936, and 43 in 1959. Disliking a rigid, pyramidal administrative structure, Nicholson encouraged direct contact with his research staff.
In the early 1950s Nicholson began a long series of important experiments, using caged Australian sheep-blowflies to study the causes of their numerical oscillations. His flair for gadgetry again emerged in the equipment he designed. His ideas on the population dynamics of insects came under criticism from some scientists—in Australia and abroad—who asserted that weather and other non-density-dependent causes were principal factors in regulating numbers. The resultant exchange of views was often far from gentlemanly and caused Nicholson much unhappiness. The controversy resulted in very tardy recognition by his peers of the major importance and relevance of his findings. It was not until 1995, at an international meeting in Canberra to mark the centenary of his birth, that opinion had swung heavily in his favour and the seminal nature of his contributions received due recognition. His chapter in The Evolution of Life (edited by S. Tax, Chicago, 1960) clarified what Charles Darwin and Alfred Wallace meant by natural selection and explained how it might work.
Nicholson retired in 1960 and was appointed C.B.E. in 1961. The Royal Society of New South Wales awarded him the (W. B.) Clarke medal in 1952, the Royal Entomological Society of London made him an honorary fellow in 1961, and the British Ecological Society elected him an honorary member in 1963. A foundation fellow of the Australian Academy of Science, he was its first secretary, biological sciences (1954-55). He was a council-member (1928-30) of the Linnean Society of New South Wales, president (1950-51) of the Royal Society of Australia, and a foundation member of the Australian Institute of Agricultural Science (1935), the Australian Entomological Society (1965) and the Ecological Society of Australia. Foundation president (1960) of the National Parks Association of the Australian Capital Territory, he presided over section D (zoology) at the 1947 congress of the Australian and New Zealand Association for the Advancement of Science.
Having arrived in Australia a shy young man, Nicholson consistently exhibited a quiet, but sustained, drive to achieve his goals. He remained self-effacing, though capable of entering effectively into debate when the need arose. His search for perfection led him to produce only twenty-five scientific papers and so delayed his writings that he left several incomplete manuscripts. Survived by his wife and two sons, he died on 28 October 1969 in Canberra Hospital and was cremated.
D. F. Waterhouse, 'Nicholson, Alexander John (1895–1969)', Australian Dictionary of Biography, National Centre of Biography, Australian National University, http://adb.anu.edu.au/biography/nicholson-alexander-john-11236/text20037, accessed 26 May 2013.
This article was first published in hardcopy in Australian Dictionary of Biography, Volume 15, (MUP), 2000