QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online March 14, 2008
Journal of Experimental Biology 211, 1029-1040 (2008)
Published by The Company of Biologists 2008
doi: 10.1242/jeb.015503

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Related articles in JEB Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Google Scholar Articles by McElroy, E. J. Articles by Reilly, S. M. PubMed PubMed Citation Articles by McElroy, E. J. Articles by Reilly, S. M.

The correlated evolution of biomechanics, gait and foraging mode in lizards

Eric J. McElroy^*, Kristin L. Hickey and Stephen M. Reilly

Ohio Center for Ecology and Evolutionary Studies and Department of Biological Sciences, Ohio University, Athens, OH 45701, USA

^* Author for correspondence (e-mail: em386403{at}ohio.edu)

Accepted 29 January 2008

Foraging mode has molded the evolution of many aspects of lizard biology. From a basic sit-and-wait sprinting feeding strategy, several lizard groups have evolved a wide foraging strategy, slowly moving through the environment using their highly developed chemosensory systems to locate prey. We studied locomotor performance, whole-body mechanics and gaits in a phylogenetic array of lizards that use sit-and-wait and wide-foraging strategies to contrast the functional differences associated with the need for speed vs slow continuous movement during foraging. Using multivariate and phylogenetic comparative analyses we tested for patterns of covariation in gaits and locomotor mechanics in relation to foraging mode. Sit-and-wait species used only fast speeds and trotting gaits coupled with running (bouncing) mechanics. Different wide-foraging species independently evolved slower locomotion with walking (vaulting) mechanics coupled with several different walking gaits, some of which have evolved several times. Most wide foragers retain the running mechanics with trotting gaits observed in sit-and-wait lizards, but some wide foragers have evolved very slow (high duty factor) running mechanics. In addition, three evolutionary reversals back to sit-and-wait foraging are coupled with the loss of walking mechanics. These findings provide strong evidence that foraging mode drives the evolution of biomechanics and gaits in lizards and that there are several ways to evolve slower locomotion. In addition, the different gaits used to walk slowly appear to match the ecological and behavioral challenges of the species that use them. Trotting appears to be a functionally stable strategy in lizards not necessarily related to whole-body mechanics or speed.

Key words: lizards, biomechanics, gait, foraging behavior, locomotor function, correlated evolution

Related articles in JEB:

FORAGING STYLE INFLUENCED HOW LIZARDS GET ABOUT

Kathryn Phillips
JEB 2008 211: ii. [Full Text]  

This article has been cited by other articles:

				K. Phillips FORAGING STYLE INFLUENCED HOW LIZARDS GET ABOUT J. Exp. Biol., April 1, 2008; 211(7): ii - ii. [Full Text] [PDF]