Robert McNeill Alexander

R. McNeill Alexander

Demonstrating a biomechanics point with a dinosaur model
Born Robert McNeill Alexander
7 July 1934
Died 21 March 2016
Alma mater University of Cambridge, University of Wales
Occupation zoologist
Employer University of Leeds, Bangor University
Awards Fellow of the Royal Society[*], Commander of the Order of the British Empire[*]

Robert McNeill (Neill) Alexander, CBE FRS[1] (7 July 1934 – 21 March 2016) was a British zoologist[2][3][4] and a leading authority in the field of biomechanics. Until 1970, he was mainly concerned with fish, investigating the mechanics of swim bladders, tails and fish jaw mechanisms. Subsequently, he has concentrated on the mechanics of terrestrial locomotion, notably walking and running in mammals, particularly on gait selection and its relationship to anatomy and to the structural design of skeletons and muscles.[1]

Education and early life

Born in Lisburn, Northern Ireland, Alexander was educated at the University of Cambridge (MA, PhD)[5] and the University of Wales (DSc).[4] His PhD research was supervised by James Gray.[2]

Career and research

After a Lectureship at University College of North Wales from 1958 to 1969, he was Professor of Zoology at the University of Leeds from 1969 until his retirement in 1999 when the title of emeritus professor was conferred upon him.[6]

Alexander was secretary of the Zoological Society of London (1992–1999) which included supervising the management of London and Whipsnade Zoos. He was president of the Society for Experimental Biology (1995–1997), President of the International Society of Vertebrate Morphologists (1997–2001) and editor of the Proceedings of the Royal Society B (1998–2004).[7]

Alexander specialised in research on animal mechanics and, apart from the books listed below, also published numerous research papers in this field since 1959.

Dinosaur locomotion

One particular area of his research interest has been into the mechanics of dinosaur motion.[8] He contributed greatly to the development of a formula used to calculate the speed of motion of dinosaurs, the so-called 'dinosaur speed calculator,' which is in fact mathematically derived from the Froude number:

"The key to deriving estimates of dinosaur gait and speed from trackways was provided by the zoologist R. McNeill Alexander (1976). From observations of modern animals he derived a general relationship between an animal's speed of locomotion (v) and its hip height (h) and its stride length (SL), which is
{v}=0.25.{g^{-0.5}}.{SL^{1.67}}.{h^{-1.17}}
Alexander also pointed out that this formula could be applied to dinosaur trackways since the stride length can be measured directly and the hip height could be estimated from the size of the foot print."[9]

Originally, Alexander stated: "I have now obtained a relationship between speed, stride length and body size from observations of living animals and applied this to dinosaurs to achieve estimates of their speeds. The estimated speeds are rather low—between 1.0 and 3.6 ms−1."[10]

But modifications to the original formula gave rise to revised estimates. And "Alexander (1996) argued that based on the bone dimensions of Tyrannosaurus it is unlikely they could have travelled at more than 8ms-1."[11] Several calculations using variants of the formula indicate that dinosaurs probably travelled at around 3 ms-1 with a top speed of 8 ms-1. This translates to a speed range of roughly 6–20 mph.

Publications

Books

  • Functional Design in Fishes, Hutchinson University Library, 1967, 1970, ISBN 0-09-104751-X
  • Animal Mechanics, Sidgwick & Jackson, 1968
  • Size and Shape, (Institute of Biology Studies in Biology), Edward Arnold, 1971
  • The Chordates, Cambridge University Press, 1975
  • Mechanics and energetics of animal locomotion, with G. Goldspink, Halsted Press, 1977
  • The Invertebrates, Cambridge University Press, 1979.
  • Optima for Animals, Hodder Arnold H&S, 1982.
  • Locomotion of animals, (Tertiary Level Biology), Springer, 1985
  • The Collins Encyclopedia of Animal Biology, HarperCollins Publishers, 1986
  • Elastic Mechanisms in Animal Movement, Cambridge University Press. 1988,
  • Dynamics of Dinosaurs and other Extinct Giants, Columbia University Press, 1989.
  • Animals, Cambridge University Press, 1990.
  • How dinosaurs ran, Scientific American, 1991
  • Animals, Cambridge University Press, 1991
  • The Human Machine, Natural History Museum, Stationery Office Books, 1992
  • Exploring Biomechanics: Animals in Motion, W H Freeman & Co, 1992
  • Bones: The Unity of Form and Function, Macmillan General Reference, 1994
  • Energy for Animal Life (Oxford Animal Biology Series), Oxford University Press, USA, 1999
  • Exploring biomechanics: animals in motion, Nikei Saiensusha, ISBN 978-4-532-52017-5
  • Hydraulic mechanisms in locomotion, In Body Cavities: Function and Phylogeny, pp. 187–198, Selected Symposia and Monographs U.Z.I., 8, Modena: Mucchi.
  • Human Bones: A Scientific and Pictorial Investigation, with Aaron Diskin, Pi Press, 2004.
  • Principles of Animal Locomotion, Princeton University Press, 2006
  • Knochen! Was uns aufrecht hält - das Buch zum menschlichen Skelett, Spektrum Akademischer Verlag, 2006

Papers

(This is a small sample from over 250 papers[12])

  • The Densities of Cyprinidae J Exp Biol 36, June 1959, pp. 333–340.
  • Visco-elastic properties of the body-wall of sea anemones J. Exp. Biol. 39, 1962, pp. 373–386.
  • Adaptation in the skulls and cranial muscles of South American characinoid fish[13]
  • Estimates of speeds of dinosaurs[10]
  • Bending of cylindrical animals with helical fibres in their skin or cuticle[14]
  • Tyrannosaurus on the run[15]
  • Dinosaur biomechanics[16]
  • Biomechanics: Stable Running[17]
  • Orangutans use compliant branches to lower the energetic cost of locomotion[18]
  • Incidence of healed fracture in the skeletons of birds, molluscs and primates[19]
  • Biomechanics: Leaping lizards and dinosaurs,[20]

Film & TV work

Honours & awards

Alexander received several awards and honours during his career including:


Personal life

Alexander married Ann Elizabeth Coulton in 1961.[4][23] He died in 2016 at the age of 81.[24]

References

  1. 1 2 3 "Professor McNeill Alexander CBE FRS". London: Royal Society. Archived from the original on 2015-11-17. One or more of the preceding sentences incorporates text from the royalsociety.org website where:
    “All text published under the heading 'Biography' on Fellow profile pages is available under Creative Commons Attribution 4.0 International License.” --Royal Society Terms, conditions and policies at the Wayback Machine (archived September 25, 2015)
  2. 1 2 Biewener, Andrew A.; Wilson, Alan (2016). "R. McNeill Alexander (1934–2016) Zoologist who pioneered comparative animal biomechanics". Nature 532 (7600): 442–442. doi:10.1038/532442a.
  3. ↑ Portraits of (Robert) McNeill Alexander at the National Portrait Gallery, London
  4. 1 2 3 ALEXANDER, Prof. (Robert) McNeill. Who's Who 2016 (online Oxford University Press ed.). A & C Black, an imprint of Bloomsbury Publishing plc. (subscription required)
  5. ↑ Alexander, Robert McNeill (2015). The physical properties of the teleost swimbladder (PhD thesis). University of Cambridge.
  6. ↑ R McNeill Alexander academic homepage at Leeds
  7. ↑ International Society of Biomechanics, Newsletter March 2011
  8. ↑ The Pterosaur Database
  9. ↑ Dinosaur speed calculator, University of Sheffield Archived 18 May 2012 at the Wayback Machine.
  10. 1 2 Alexander, R. McN. (1976). "Estimates of speeds of dinosaurs". Nature 261 (5556): 129–130. doi:10.1038/261129a0.
  11. ↑ Dinosaur Gait and Estimates of Speeds, University of Bristol
  12. ↑ "Robert McNeill Alexander, zoologist - obituary". The Daily Telegraph. 3 April 2016. Retrieved 3 May 2016.
  13. ↑ Alexander, R. McN. (1964). "Adaptation in the skulls and cranial muscles of South American characinoid fish". Journal of the Linnean Society of London, Zoology 45 (305): 169–190. doi:10.1111/j.1096-3642.1964.tb00493.x.
  14. ↑ Alexander, R.McN. (1987). "Bending of cylindrical animals with helical fibres in their skin or cuticle". Journal of Theoretical Biology 124 (1): 97–110. doi:10.1016/S0022-5193(87)80255-2.
  15. ↑ Alexander, R. McNeill (1996). "Tyrannosaurus on the run". Nature 379 (6561): 121–121. doi:10.1038/379121a0. ISSN 0028-0836.
  16. ↑ Alexander, R. M. (2006). "Dinosaur biomechanics". Proceedings of the Royal Society B: Biological Sciences 273 (1596): 1849–1855. doi:10.1098/rspb.2006.3532. PMC 1634776.
  17. ↑ Alexander, R. McNeill (2007). "Biomechanics: Stable Running". Current Biology 17 (7): R253–R255. doi:10.1016/j.cub.2007.02.001.
  18. ↑ Alexander, R.McN.; Crompton, R.H.; Thorpe, S.K.S. (2007). "Orangutans use compliant branches to lower the energetic cost of locomotion". Biology Letters 3 (3): 253–256. doi:10.1098/rsbl.2007.0049.
  19. ↑ Brandwood, A.; Jayes, A. S.; Alexander, R. Mcn (2009). "Incidence of healed fracture in the skeletons of birds, molluscs and primates". Journal of Zoology 208 (1): 55–62. doi:10.1111/j.1469-7998.1986.tb04708.x. ISSN 0952-8369.
  20. ↑ Alexander, R. McNeill (2012). "Biomechanics: Leaping lizards and dinosaurs". Nature. doi:10.1038/nature10797.
  21. ↑ Robert McNeill Alexander at the Internet Movie Database
  22. ↑ The University of Leeds, Reporter 455, September 2000
  23. ↑ The International Who's Who 2004, Europa Publications
  24. ↑ University of Leeds, obituary notice
Professional and academic associations
Preceded by
Barry Albert Cross		 Secretary of the
Zoological Society of London
1992–1999 		Succeeded by
Paul H. Harvey
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