Omnivory in lacertid lizards: adaptive evolution or constraint?
Article first published online: 7 JUN 2004
Journal of Evolutionary Biology
Volume 17, Issue 5, pages 974–984, September 2004
How to Cite
Herrel, A., Vanhooydonck, B. and Van Damme, R. (2004), Omnivory in lacertid lizards: adaptive evolution or constraint?. Journal of Evolutionary Biology, 17: 974–984. doi: 10.1111/j.1420-9101.2004.00758.x
- Issue published online: 7 JUN 2004
- Article first published online: 7 JUN 2004
- Received 26 March 2004; accepted 4 April 2004
- bite force;
- digestive tract;
Feeding specializations such as herbivory are an often cited example of convergent and adaptive evolution. However, some groups such as lizards appear constrained in the evolution of morphological specializations associated with specialized diets. Here we examine whether the inclusion of plant matter into the diet of omnivorous lacertid lizards has resulted in morphological specializations and whether these specializations reflect biomechanical compromises as expected if omnivores are constrained by functional trade-offs. We examined external head shape, skull shape, tooth structure, intestinal tract length and bite performance as previous studies have suggested correlations between the inclusion of plants into the diet and these traits. Our data show that omnivorous lacertid lizards possess modifications of these traits that allow them to successfully exploit plant material as a food source. Conversely, few indications of a compromise phenotype could be detected, suggesting that the evolution towards herbivory is only mildly constrained by functional trade-offs.