Correlating Shape Variation with Feeding Performance to Test for Adaptive Divergence in Recently Invading Stickleback Populations from Swiss peri-alpine Environments

The purpose of this chapter is to demonstrate the application of geometric morphometrics in a typical study, and put the information it provides into a broader context. Here we use geometric morphometrics to describe the head shape among three different Swiss stickleback populations from two drainages, including both lake and stream residents. Head shapes are compared to feeding efficiency indices generated from laboratory trials using lake and stream prey types. We also combine these data with genetic and other more traditional morphological assessments to understand the roots of the tremendous variation exhibited by sticklebacks in Switzerland. This work shows that in combination with other data, geometric morphometrics can make a significant contribution toward understanding the natural history of taxa and is an indispensible tool providing insight into fundamental mechanisms of adaptive divergence and speciation.