Morphometric analysis of Scaphinotus petersi populations in the Arizona Sky Islands

Geographically isolated habitats such as the conifer forests atop the Sky Islands in southeastern Arizona provide natural laboratories for studying the processes involved in speciation and origins of biodiversity.  We examined the morphological variation within and among populations of an endemic, flightless, carabid beetle species, Scaphinotus petersi, restricted to montane conifer forests.  Using linear measurements of several characteristics and geometric morphometric analyses of shape changes in pronota and heads, we found morphological variation within the S. petersi species and among several isolated mountain range populations, suggesting evolutionary divergence in morphological traits.