COMMENT OBITUARY R. McNeill Alexander (1934–2016) Zoologist who pioneered comparative animal biomechanics.

obert McNeill Alexander defined dinosaurs’ (Nature 261, 129–130; 1976). many fundamental properties of how Alexander’s work fuelled the emerging animals move. He combined elegant field of biorobotics. He participated in a Rmechanical and mathematical analyses to European effort to build a robot dinosaur, reduce problems in flight, swimming, walk- advising on the probable gait and a simpli- ing, running and anatomy to their simplest fied arrangement of joints for the creature. level. He explained the importance of iner- His findings also contributed to improved tial forces versus gravitational ones in deter- gait rehabilitation and prosthetic devices for mining which gaits land animals use to move people. His coffee-table book Bones (Prentice at different speeds, and he predicted the pace Hall, 1994) reveals the beauty inherent in at which dinosaurs probably moved. the biomechanics of animals. His 1995 edu- His work showed why animals of different cational CD How Animals Move was widely sizes move in similar ways, as well as the used in schools and universities; it remains JOHN ARNISON/NATIONAL PORTRAIT GALLERY, LONDON PORTRAIT GALLERY, JOHN ARNISON/NATIONAL importance of the elastic energy stored in ten- the best teaching aid of its kind. dons in reducing the metabolic cost of jump- Neill was devoted to comparative biome- ing and running. Alexander wrote 20 books, chanics and its wider appreciation. He served including his classic text Animal Mechanics as secretary to the Zoological Society of Lon- (Sidgwick and Jackson, 1968). He published don from 1992 to 1999 (after the reversed more than 280 scientific papers. On most sub- theoretical modelling. In collaboration with decision to close London Zoo). He served jects in biomechanics, it would be wise to first Harvard University physiologist C. Richard as president of the Society for Experimental read what Alexander had to say. Taylor and Kenyan veterinary scientist Biology and the International Society of Ver- Born in 1934 in Lisburn, UK, to the chief Geoffrey Maloiy, he examined movement tebrate Morphology and as editor of the jour- engineer of the city of Belfast Robert Alexan- in African mammals as diverse as dik-dik nal Proceedings of the Royal Society B. Among der and author Janet McNeill, he was inspired and buffalo. He formulated a model that his many honours, Neill was elected fellow at school by his biology teacher Arnold Beni- explained how and why animals move in of the Royal Society in 1987 and appointed ngton, a BBC radio naturalist. Aged 16 or 17, similar ways, and he used Froude numbers Commander of the Order of the British Alexander published his first paper ‘Behav- (previously deployed by Victorian engineer Empire in 2000. The gong that gave him the iour of the robin during laying’ (Brit. Birds 44, William Froude in his analysis of the bow most amusement — and best captured his 389–390; 1951), after a pair nested on top of a waves of ships) to explain how the length Gandalf-like status — came in 1996, when wardrobe in his bedroom. That year, he also of limbs affects speed and gait over ground. British newspaper The Mail on Sunday listed won an essay prize from the Royal Society for Alexander also built theoretical models of him as one of “Britain’s Nuttiest Professors — the Protection of Birds for an experiment to foraging and migration, suggesting that only Ten Sages Who Really Know Their Onions”. test if birds would remember which trough on birds or large mammals benefit from the risks In retirement, Neill continued to attend his windowsill contained hidden food. and energy costs of long-distance travel. professional meetings, give lectures and serve At the University of Cambridge, Alexander Alexander compared the athletic on examination committees. He advised on read natural sciences. He completed a PhD performance of humans with that of other television documentaries, including the on the function of swim bladders in fish. His animals. He discovered that small animals BBC’s 2001 series Walking with Beasts. As a supervisor was James Gray, a pioneer of com- rely on the rapid release of elastic energy reviewer, he was always succinct, insightful parative experimental studies of animal loco- stored in their tendons to jump high and far, and supportive of good science. He visited motion. He also acted, including a memorable whereas humans and larger animals stretch every poster at conferences, where he con- appearance as the giant Harapha in a produc- their muscles with force to achieve greater veyed his passion to students and remained a tion of John Milton’s Samson Agonistes. And heights. And he evaluated the evolutionary role model. Neill was warm and animated in he travelled extensively in Europe, meeting and energetic consequences of building and conversation and broad-minded when com- his wife Ann, also a student at Cambridge, on maintaining physiological and mechanical municating his science. He was an inspiration a trip to Italy in 1956. He was an expedition structures that are necessary for locomo- and generous mentor to many of today’s lead- scientist on a Cambridge trip to the jungles tion, such as those that facilitate respiratory ers in the scientific field that he established. ■ of Guyana in 1960. After a lectureship at the gas transport and musculoskeletal support. University College of North Wales (now Ban- His family indulged his research Andrew A. Biewener is professor of biology gor University) from 1958 to 1969, Alexander endeavours. In the 1970s, while developing at Harvard University in Cambridge, became professor of zoology at the University an approach to derive the speeds of dino- Massachusetts, USA, and director of the of Leeds, until his retirement in 1999. saurs from their fossilized tracks, Alexander Concord Field Station, where he collaborated In the early 1960s, the functional analysis took his two children to Snettisham beach with Neill Alexander. Alan Wilson is of animal form was driven by descriptive in Norfolk, UK. There, they walked and professor of locomotor biomechanics at comparisons of morphology that largely ran along various textures of mud, count- the Royal Veterinary College in London. lacked mathematical expression. Alexander ing their strides and timing themselves Alexander examined Wilson’s PhD thesis. addressed this by combining field stud- with a stopwatch. These antics are recorded e-mails: [email protected]; ies with laboratory experimentation and in the paper ‘Estimates of speeds of [email protected].

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