Development and evolution of animal biomineral skeletons

Uncovering the developmental, molecular, and cellular mechanisms by which different organisms grow and develop is fundamental for understanding the evolution of the diversity of animal forms seen on the planet today. It is unclear, however, how changes in gene expression during ontogeny result in the diversity of animal body plans seen in the planet today. This project will thus aim to link genotype to phenotype to understand the role of gene expression and ontogeny in the evolution of biomineralized skeletons. Sea urchins are a model system for understanding the evolution of skeletal morphology because the genetic regulatory networks that build their larval and embryonic skeletons are well known. Furthermore, they have a well-sampled fossil record, which makes them an ideal model system to understand evolutionary changes in morphology seen in deep time. The aim of this project is to quantify morphological changes in skeletal morphology during ontogeny of the sea urchin Mespilia globulus, and then identify the molecular mechanisms underlying skeletal growth. The student will then compare morphology at different developmental stages to the fossil record of echinoderms to test the hypothesis that morphological differences in the skeleton of different echinoderm groups is underlain by changes in ontogeny.