The Evolution of Ant Mandibles & Advancing Comparative Morphology in 3D

Abstract

Okinawa Institute of Science and Technology Graduate UniversityDoctor of PhilosophyThe diversity of life manifests in the countless forms of organisms, which are a key to understanding natural selection, the interface between genomes and the environment, and functional traits. Ants evolved a broad trophic spectrum and perform vastly different behaviors, universally exhibit a social lifestyle, their range of body plans is highly disparate, and they dominate terrestrial ecosystems. However, despite success in diversification and abundance, we lack an understanding of the factors that promote their morphological diversification or the functional constraints and tradeoffs that incur in ant evolution. In this thesis, I focus on a broad comparative study on the mandibles as the primary tools that ants use in social, environmental, and dietary interactions. I further developed workflows for phenotyping anatomy and spearheaded an initiative, which lays out how to obtain much more standardized 3D anatomical data suitable for automated methods than previously possible. In summary, chapter one of the thesis mainly addresses the solidification of automated muscle analysis based on CT-data. Central to chapter two is Antscan, a pilot project for creating digital libraries of 3D invertebrate anatomy based on high-throughput synchrotron µCT. Based on segmented data for over 600 individual ants, in chapter three, I found that the triangular ant mandible is a ground plan, which ants have mostly retained and remained conservative with. However, convergently evolved shapes driven by functional demands advantageous in predation and division of labor account for overall high morphological diversity. In this thesis, I unraveled contrasts among dimensions of diversity and enabled further research into 3D insect morphology by providing data directly and documenting how to obtain and analyze it and I hope that this work will make a useful contribution to biodiversity science.doctoral thesi