Information content is more important than sensory system or physical distance in guiding the long-term evolutionary relationships between signaling modalities in Sceloporus lizards
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Long-term signal evolution is shaped by a variety of selective pressures including the need to convey additional information or to improve message transfer to specific receivers or through multiple environments. Here, we test the relative importance of information and sensory modality in shaping the long-term evolution of multimodal signals in Sceloporus lizards. To broadcast identity at territorial boundaries, male Sceloporus use both visual motion (headbob) and chemical signals, whereas they use color (blue belly patches) to signal aggression. Using modern phylogenetic comparative methods, we found a negative correlation between evolutionary changes in visual motion (headbobs) and chemical (femoral pore) signals, but only indirect ties between the evolution of color and motion signals (both of which are perceived visually) through viviparity, and no evidence of an evolutionary link between color and chemical signals. We also find a negative correlation between arboreality and chemical signals. Thus, information content (in this case, broadcasting individual identity versus signaling aggression) appears to play a more important role than sensory modality or physical distance in guiding long-term signal evolution. Additional insights into the underlying evolutionary processes are described, illustrating the utility of a phylogenetic approach.
KeywordsPhylogenetic comparative methods Sceloporus lizards Multimodal signaling Communication Trade-offs
We thank Eileen Hebets and two anonymous reviewers for comments on this manuscript. This material is based upon the work supported by the National Science Foundation under grant numbers IOS-1050274 to EPM and IOS-1052247 to DKH. JAF was supported by a fellowship from Colciencias.
- Carpenter CC (1978) Comparative display behavior in the genus Sceloporus (Iguanidae). Contr Biol Geol Milw Publ Mus 18:1–71Google Scholar
- Guillette LJ Jr, Jones RE, Fitzgerald KT, Smith HM (1980) Evolution of viviparity in the lizard genus Sceloporus. Herpetologica 36:201–215Google Scholar
- Hews DK, Quinn VS (2003) Endocrinology of species differences in sexually dimorphic signals and aggression: using the organization and activation model in a phylogenetic framework. In: Fox SF, Baird T, McCoy J (eds) Lizard social behavior. Johns Hopkins University Press, Baltimore, pp 253–277Google Scholar
- Kohler G, Heimws P (2002) Stachelleguane. Lebensweise, Pflege, Zucht. Herpeton Verlag, OffenbachGoogle Scholar
- Martins EP (2004) COMPARE, version 4.6b. Computer programs for the statistical analysis of comparative data. Distributed by the author at http://compare.bio.indiana.edu/. Department of Biology, Indiana University, Bloomington.
- Ord TJ, Charles GK, Hofer RK (2011) The evolution of alternative adaptive strategies for effective communication in noisy environments. Am Nat 177:54–64Google Scholar
- Pagel M, Meade A (2011) BayesTraits v1.0. School of Biological Sciences, University of Reading, Reading, UK. Available at: www.evolution.rdg.ac.uk.
- Painter D, Jennings DH, Moore MC (2002) Placental buffering of maternal steroid hormone effects on fetal and yolk hormone levels: a comparative study of a viviparous lizard, Sceloporus jarrovi, and an oviparous lizard, Sceloporus graciosus. Gen Comp Endocrinol 127:105–116PubMedCrossRefGoogle Scholar
- Smith HM (1939) The Mexican and Central American lizards of the genus Sceloporus, vol 26. Field Museum of Natural History, ChicagoGoogle Scholar
- Webb RG (2009) Crevice spiny lizard. In: Jones LLC, Lovich RE (eds) Lizards of the American Southwest: a photographic field guide. Rio Nuevo, Tucson, pp 246–249Google Scholar