Dr. Heather Bracken-Grissom, an evolutionary biologist in the Center for Coastal Oceans Research, was recently awarded over $450,000 by the National Science Foundation to lead research on crab evolution. The project aims to reconstruct the crab “tree of life” and explain the diversity of body shapes across the almost 10,000 species in the group.
Bracken-Grissom will investigate how crabs have changed over 200 million years in collaboration with Dr. Joanna Wolfe and Dr. Javier Ortega-Hernandez from Harvard University’s Department of Organismic & Evolutionary Biology and Dr. Javier Luque from Yale University. She and her colleagues will first build the tree of life for all known living and fossil crab families, estimate the origins of major lineages by dating the tree and study the evolution of the crab-like body form, also known as carcinisation.
“This will provide a framework for answering questions about rapid diversification across deep time and the evolution of complex forms and functions,” said Bracken-Grissom.
Over the years, the crab-like body has evolved four to five times from its lobster-like ancestors among decapod crustaceans. This makes it ideal for studying trends in biodiversity through geologic time. Bracken-Grissom hopes this work will shed some light on why the crab-like groups are so successful in terms of species diversity compared to their shrimp and lobster relatives.
“This is not just a question for decapod crustaceans, this is an outstanding question across several groups and the field of evolutionary biology,” Bracken-Grissom adds.
The project will enhance the participation of underrepresented groups in research through museum activities for high school and graduate students and active-learning modules for undergraduate students. Mentored through training courses held in Panama about tropical crab taxonomy, future scientists in the U.S. and Latin America will be privy to tools to help further current research.
Learn more about Bracken-Grissom’s CRUSTOMICS lab here.
*Figure 1: Convergent uncarcinized and decarcinized body forms in Anomura and Brachyura. (a-d) Anomura: (a) Hippidae, Hippa marmorata, Taiwan. (b) Albuneidae, Albunea occulta. (c) Blepharipodidae, Blepharipoda occidentalis. (d) Porcellanidae, Euceramus panatelus, Panama. (e-i) Brachyura: (e-f), Raninidae: (e) Raninoides benedicti, Panamá. (f) Symethis sp. Panamá. (g) new fam. gen. and sp., mid-Cretaceous, Colombia and USA. (h-i) Eubrachyura, Corystidae: (h) Corystes cassivelaunus, Belgium. (i) Jonas distinctus, Taiwan.