Table of Contents
International Journal of Evolutionary Biology
Volume 2012, Article ID 647420, 12 pages
http://dx.doi.org/10.1155/2012/647420
Review Article

An Evaluation of the Role of Sensory Drive in the Evolution of Lake Malawi Cichlid Fishes

1Department of Biology, Indiana University, 1001 East 3rd Street, Jordan Hall 142, Bloomington, IN 47405, USA
2Department of Biological Sciences, Bowling Green State University, 217 Life Sciences Building, Bowling Green, OH 43403, USA
3Department of Biology, University of Maryland, 1210 Biology-Psychology Building, College Park, MD 20742, USA

Received 28 December 2011; Revised 15 March 2012; Accepted 5 April 2012

Academic Editor: Martin J. Genner

Copyright © 2012 Adam R. Smith et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Although the cichlids of Lake Malawi are an important model system for the study of sensory evolution and sexual selection, the evolutionary processes linking these two phenomena remain unclear. Prior works have proposed that evolutionary divergence is driven by sensory drive, particularly as it applies to the visual system. While evidence suggests that sensory drive has played a role in the speciation of Lake Victoria cichlids, the findings from several lines of research on cichlids of Lake Malawi are not consistent with the primary tenets of this hypothesis. More specifically, three observations make the sensory drive model implausible in Malawi: (i) a lack of environmental constraint due to a broad and intense ambient light spectrum in species rich littoral habitats, (ii) pronounced variation in receiver sensory characteristics, and (iii) pronounced variability in male courtship signal characteristics. In the following work, we synthesize the results from recent studies to draw attention to the importance of sensory variation in cichlid evolution and speciation, and we suggest possible avenues of future research.