GEOMETRIC MORPHOMETRICS

The aim of this article is to provide a simple introduction to Geometric MorphoMetrics (GMM). GMM is the numerical study of the interaction of size and shape with covarying factors in biology. It represents the modern form of morphometrics, a discipline with a century long history, and it includes a variety of methods. GMM makes extensive use of the advances in computer technology and digital imaging, providing tools to analyse and collect data within a rigorous statistical framework. Thanks to the combination of analytical power and intuitive visualizations using computer graphics, GMM has rapidly emerged as one of the most widely applied disciplines in biology. In this review, I will: 1) briefly summarize the history of morphometrics; 2) provide a rapid overview of the new methods; 3) describe and exemplify the analysis of anatomical landmark coordinates using Procrustes methods, the leading set of techniques in morphometrics. Specific topics, which may not be of interest for the general reader but could be of help to those who may want to learn and apply these methods, are discussed in a series of sections in the Appendix.