Research

My laboratory is interested in the mechanistic basis of animal behavior. A variety of animal species from diverse groups serve as models. Currently, my lab has two main research tracks. First, we are investigating the evolution of tetrapod (four-footed land animals: mammals, birds, reptiles, amphibians) locomotion by quantifying underwater locomotion using the limbs in salamanders. This may sound odd, but the fossil evidence indicates that the appearance of the tetrapod limb and foot pre-dated the move to land. Thus, one wants a model that approximates the posture of early tetrapods, and salamanders are our best available match. Second, we are examining the biomechanics of prey capture in tarantulas. These large, hairy, ground-dwelling spiders can capture small arthropods (such as crickets) in less than one-tenth of a second. Just how they detect and capture their prey is our current interest. My graduate students are working on such diverse projects as the function of the median fins during the escape response in fish, and the development of feeding biomechanics in a blind cave salamander. Techniques that we use are high-speed video, electromyography (recording patterns of muscle activity), sonomicrometry, and in vitro measures of muscle work and power output.

Selected Publications

Young, B.A. and M.A. Ashley. 1989. A mathematical model for predicting relative muscle force with a perturbation analysis of selected muscle parameters. Journal of Theoretical Biology, 138: 213-233.

Ashley, M. A., Reilly, S. M., and G.V. Lauder. 1991. Ontogenetic scaling of hindlimb muscles across metamorphosis in the tiger salamander, Ambystoma tigrinum. Copeia, 1991(3): 767-776.

Ashley-Ross, M.A. 1992. The comparative myology of the thigh and crus in the salamanders Ambystoma tigrinum and Dicamptodon tenebrosus. Journal of Morphology, 211: 147-163.

Ashley-Ross, M.A. 1994. Hind limb kinematics during terrestrial locomotion in a salamander (Dicamptodon tenebrosus). Journal of Experimental Biology, 193: 255-283.

Ashley-Ross, M.A. 1994. Metamorphic and speed effects on hind limb kinematics during terrestrial locomotion in the salamander Dicamptodon tenebrosus. Journal of Experimental Biology, 193: 285-305.

Ashley-Ross, M.A. 1995. Patterns of hind limb motor output during walking in the salamander Dicamptodon tenebrosus, with comparisons to other tetrapods. Journal of Comparative Physiology A, 177: 273-285.

Ashley-Ross, M.A. and G.V. Lauder. 1997. Motor patterns and kinematics during backward walking in the Pacific Giant Salamander: evidence for novel motor output. Journal of Neurophysiology, 78: 3047-3060.

Rome, L.C., Cook, C., Syme, D.A., Connaughton, M., Ashley-Ross, M.A., Klimov, A., Tikunov, B., and Y.E. Goldman. 1999. Trading force for speed: why superfast cross-bridge kinetics lead to super low forces. Proceedings of the National Academy of Science, USA, 96: 5826-5831.

Butcher, M.T. and M.A. Ashley-Ross. 2002. Fetlock joint kinematics differ with age in Thoroughbred racehorses. Journal of Biomechanics, 35: 563-571.

Ashley-Ross, M.A. and G.B. Gillis. 2002. A brief history of vertebrate functional morphology. Integrative and Comparative Biology (formerly American Zoologist), 42(2): 183-189.

Ashley-Ross, M.A. and J.U. Barker. 2002. The effect of fiber type heterogeneity on optimized work and power output of hindlimb muscles of the salamander Ambystoma tigrinum. Journal of Comparative Physiology A, 188: 611-620.

Ashley-Ross, M.A. 2002. Mechanical properties of the dorsal fin muscle of seahorse (Hippocampus) and pipefish (Syngnathus). Journal of Experimental Zoology, 293: 561-577.

Morgan, S.M., Ashley-Ross, M.A., and D.J. Anderson. 2003. Foot-mediated incubation: Nazca booby (Sula granti) feet as surrogate brood patches. Physiological and Biochemical Zoology, 76(3): 360-366.

Ashley-Ross, M.A. and B.F. Bechtel. 2004. Kinematics of the transition between aquatic and terrestrial locomotion in the newt Taricha torosa. Journal of Experimental Biology, 207: 461-474.

Morgan, S.M., Clifford, L.D., Ashley-Ross, M.A. and D.J. Anderson. 2004. Parental responses to unexpectedly cool eggs in Nazca boobies Sula granti. Journal of Avian Biology, 35: 416-424.

Walthall, J.C. and M.A. Ashley-Ross. 2006. Postcranial myology of the California newt, Taricha torosa. Anatomical Record, 228A:46-57.

Ashley-Ross, M.A., Lundin, R., and K.L. Johnson. 2009. Kinematics of level terrestrial and underwater walking in the California newt, Taricha torosa. Journal of Experimental Zoology A, 311(4): 240-257.