Geometric morphometrics and rock art: exploring landmark-based methods

Abstract

The aim of this work is to explore the application of geometric morphometric landmark- based methods to study shape and size changes on rock art quantitatively. It is done as a methodological exercise, aiming to show the analitic potential of these methods. They have been applied on a sample of 116 paintings and engravings from sites assigned to late Holocene located in Quebrada de Humahuaca and Puna (Jujuy province). The figures are camelids from Playa Colanzuli, Media Agua, Sapagua and Barrancas sites. A brief introduction to geometric morphometrics is presented, including its origins, aims, different methods and advantages in relation with traditional morphometrics. Then, landmark-based method technical procedures and work images protocol are described. Finally, three types of statistical multivariate analyses are presented. These analyses are applied here to describe: 1) the main morphological variations (principal component analysis), 2) the shape differences between groups (canonical variate analysis and parametric and non parametric hyphothesis tests) and 3) the relationship between size and shape (multiple regression).