Geometric morphometric methods for analysis of complex symmetric structures

• Main Author: Savriama, Yoland
• Published: University of Manchester 2008
• Subjects: 571.3
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.491861

Bilateral symmetry is the simplest and most common type of symmetry in organisms and for this reason it has been extensively studied in many biological contexts. Geometric morphometrics is concerned with the quantification of morphological variation in organisms and has been specifically developed for studies of symmetry and asymmetry. Most studies of symmetry have focused on bilaterally symmetric structures (e.g., human faces). However, bilateral symmetry is not the only type of symmetry in biological shapes and other types of symmetry exist as well (e.g., radial symmetry in flowers). So far, there are no general methods for morphological analysis of these types of symmetry. Here, I propose a new and general approach for norphological analysis of structures with any type of symmetry. This framework combines the tools of geometric morphometries with a mathematical definition of symmetry. Depending on the type of symmetry under study, this method can separate a component of symmetric variation among individuals from one or more asymmetry components.