Stephen M. Levin
Ezekiel Biomechanics Group
SMLevin@biotensegrity.com
Presented in the Embryo Physics Course, January 15, 2014
Abstract
Embryologic development, from ‘origin of life’ to organism, has been regarded by scientists as a series of chance occurrences, the “Blind Watchmaker” theory popularized by Richard Dawkins, “a universe without design”. What is argued in this talk is that the laws of physics as applied to structures must play a dominant, and often deciding, role in organism structure and evolution. Structural stability of the developing organism becomes a driving force and adherence to physical laws makes much of emergence “deterministic”. Only certain forms are acceptable and physical laws must be followed. A newly developing embryo will always cede to stable configuration rather than an unstable one, and to a lesser energy form rather than to a higher energy consuming form. The underlying structural ‘design’ features from viruses to vertebrae, their systems and sub-systems, are remarkably similar. ‘Chance’ is only relative and whatever emerges can do so only by following physical Laws. To quote D’Arcy Thompson,”Cell and tissue, shell and bone, leaf and flower, are so many portions of matter, and it is in obedience to the laws of physics that their particles have been moved, moulded and conformed.” We introduce the concept of “tensegrity” as the underlying mechanical structural organization that holds it all together.
Presentation
/files/presentations/2/Levin2014.pdf
I was wrong about there not being general software for tensegrity computations of cytoskeleton. See:
Lai, V.K., M.F. Hadi, R.T. Tranquillo & V.H. Barocas (2013). A multiscale approach to modeling the passive mechanical contribution of cells in tissues. Journal of Biomechanical Engineering-Transactions of the ASME 135(7).
Kardas, D., U. Nackenhorst & D. Balzani (2013). Computational model for the cell-mechanical response of the osteocyte cytoskeleton based on self-stabilizing tensegrity structures. Biomechanics and Modeling in Mechanobiology 12(1), 167-183.
Barreto, S., C.H. Clausen, C.M. Perrault, D.A. Fletcher & D. Lacroix (2013). A multi-structural single cell model of force-induced interactions of cytoskeletal components. Biomaterials 34(26), 6119-6126.
Wang, S. & P.G. Wolynes (2012). Tensegrity and motor-driven effective interactions in a model cytoskeleton. Journal of Chemical Physics 136(14).
Chen, T.-J., C.-C. Wu & F.-C. Su (2012). Mechanical models of the cellular cytoskeletal network for the analysis of intracellular mechanical properties and force distributions: A review. Medical Engineering & Physics 34(10), 1375-1386.
Bursa, J., R. Lebis & J. Holata (2012). Tensegrity finite element models of mechanical tests of individual cells. Technology and Health Care 20(2), 135-150.
Alippi, A., A. Bettucci, A. Biagioni, D. Conclusio, A. D’Orazio, M. Germano & D. Passeri (2012). Non linear behaviour of cell tensegrity models. In: International Congress on Ultrasonics (Gdansk 2011). Ed. 1433: 329-332.
Volokh, K.Y. (2011). On tensegrity in cell mechanics. Molecular & Cellular Biomechanics 8(3), 195-214.
Stamenović, D. (2006). Models of cytoskeletal mechanics based on tensegrity. In: Cytoskeletal Mechanics: Models and Measurements. Ed.: M.R.K. Mofrad & R. Kamm, Cambridge University Press: 103-128.