The Use of Geometric Morphometrics in Studying Butterfly Wings in an EvolutionaryEcological Context

In order to quantify shape variation, many powerful, free, easy-to-use and dedi- cated software packages have been developed that quickly digitize and/or anal- yse landmark data (e.g. the tps suite by Rohlf, http://life.bio.sunysb.edu/morph/). Furthermore, powerful shape analyses can also be carried out in statistical pack- ages such as R (Claude 2008). Unlike 10–20 years ago, these days it is therefore no longer difficult to accurately record the position of landmarks on any biological structure. Furthermore, such landmark configurations can easily be compared within and between species using a variety of analyses that together comprise the field of geometric morphometrics (Zelditch et al. 2004). The theoretical core of geomet- ric morphometrics has been well described and is easy to understand, and as such geometric morphometrics can easily be implemented in a wide variety of research fields, such as evolutionary ecology (Zelditch et al. 2004). Using the speckled wood butterfly Pararge aegeria (L.) (Nymphalidae, Satyrinae) as our model species, we will illustrate the variety of uses to which geometric morphometrics can be applied to understand the effects of the environment on possibly adaptive butterfly wing size and shape variation in ecologically relevant contexts.