Introduction to morphometric analysis

Abstract

Morphometrics is the study of shape and its relation to size. This chapter presents the use of some morphometric techniques in order to compare shape alterations in function of size, and to test whether differences in allometric scaling cause shape divergence. Bivariate techniques such as morphometric ratios and simple regressions are introduced. The multivariate patterns in ecology and systematics are usually explored using principal component (PCA) and discriminant analysis. Herein PCA, shear analysis, size-free discriminant analysis and multivariate allometric coefficient are inc1uded. To test whether morphometric parameters are significant, resampling techniques (jackknife and boostrap) and randomization processes are provided, In addition, some ecomorphologícal issues are presented, such as: species convergence, communities convergence and community organization.