Physiology

Plant PhysiologyPlants

Without plants, life on our planet would be very different indeed.  Plants can move only by growing, except for the odd carnivorous plant, and so respond to environmental changes by very different strategies relative to those deployed by animals. These adaptations and exaptations raise a host of physical and physico-chemical questions that beg for a quantitative treatment from both an experimental and a theoretical perspective. The diversity of plant and fungal life on our planet raises questions from the range of leaf and flower shapes to the ability to silently haul water to the top of a giant Sequoia, the myriad mechanisms for seed and spore dispersal, carnivory and rapid movements, etc.  at the interface of biology and physics.  Our occasional studies in this area have focused on aspects of hydraulically-driven movements in plants and fungi, the morphometry and morphogenesis of shoots, leaves and flowers, the design principles underlying transpiration, and proprioceptive feedback in growth. We are also interested using plant physiology as an inspiration for engineered devices.

Animals

A particular interest is that of locomotion physiology. Animals move in diverse manners, and we have studied many of these locomotory gaits – walking, crawling, swimming, slithering, etc. from a theoretical perspective to understand the neurodynamics of locomotion, as well as their ecodynamics, created theories for the different gaits of long slender animals such as crawling snails, and worms, undulating snakes, flexing fishes etc. and showed that tuning a single parameter suffices to explain the gait transitions from crawling to undulation to inch-worming, while also explaining how they respond to stimuli in the context of simple behavioral strategies such as thermotaxis.

We have shown how one can derive general scaling principles underlying macroscopic aquatic locomotion  which capture the essence of locomotion from shrimps to whales, again showing how physical constraints lead to evolutionary convergence, with lessons for robotic swimmers,  the evolution of locomotion using robot-like objects, gaits and gait transitions in slender organisms such as snakes, and simple aspects of learning and coordination in primitive organisms.

Related Publications

How the Venus Flytrap snaps Y. Forterre, J. Skotheim, J. Dumais and L. Mahadevan,  Nature,  433, 421-25, 2005. [View PDF] [Download PDF]
Physical limits and design principles for plant and fungal movements J. Skotheim and L. Mahadevan,  Science,  308, 1308-10, 2005. [View PDF] [Download PDF]
The shape of a long leaf H. Liang and L. Mahadevan,  Proceedings of the National Academy of Sciences (USA) ,106, 22049, 2009. [View PDF] [Download PDF]
Growth, geometry and mechanics of the blooming lily H-Y. Liang and L. Mahadevan,  Proceedings of the National Academy of Sciences , 108, 5516-21, 2011. [View PDF] [Download PDF]
On the growth and form of shoots R. Chelakkot and L. Mahadevan,  Journal of the Royal Society Interface , 14, 20170001, 2017. [View PDF] [Download PDF]
Botanical ratchets I. Kulic, M. Mani, H. Mohrbach, R. Thaokar, L. Mahadevan,  Proceedings of the Royal Society of London (B), Biological Sciences , 276, 2243-47, 2009. [View PDF] [Download PDF]
Motility driven by macromolecular springs and ratchets, Mahadevan, L. and P. Matsudaira,  Science , 288, 95-99, 2000. [View PDF] [Download PDF]
Biomimetic ratcheting motion of lubricated hydrogel filaments, Mahadevan, L., S. Daniel and M. Chaudhury,  Proceedings of the National Academy of Sciences (USA) , 101, 23-26, 2004. [View PDF] [Download PDF]
Limbless undulatory propulsion on land Z. Guo and L. Mahadevan,  Proceedings of the National Academy of Sciences (USA),  105, 3179, 2008. [View PDF] [Download PDF]
Scaling macroscopic aquatic locomotion M. Gazzola, M. Argentina and L. Mahadevan,  Nature Physics , 10, 758-61, 2014. [ONLINE ARTICLE] [View PDF] [Download PDF]
Gait and speed selection in slender inertial swimmers M. Gazzolaa, M. Argentina and L. Mahadevan,  Proceedings of the National Academy of Sciences  112, 13, 2015. [View PDF] [Download PDF]
Elastohydrodynamic scaling law for heart rates. E. Virot, V. Spandan, L. Niu, W. M. van Rees, and L. Mahadevan, Phys. Rev. Lett. (2020) 125.058102. [DOI] [View PDF] [Download PDF]
A proprioceptive neuromechanical theory of crawling P. Paoletti and L. Mahadevan,  Proceedings of the Royal Society (B) , 281, 20141092, 2014. [View PDF] [Download PDF]
Integrative neuromechanics of crawling in D. melanogaster larvae C. Pehlevan, P. Paoletti, L Mahadevan  eLife,  5:e11031,  2016. [View PDF] [Download PDF]
Coordinated crawling via reinforcement learning. S. Mishra, W. van Rees, L. MahadevanRoyal Society-Interface, (2020), 17: 20200198. [DOI] [View PDF] [Download PDF]