The chiton radula as a model system for investigating iron regulation and iron stress

Multiple solutions to spatial imaging in chitons - parallel tracks on evolution's tape

Chitons (Polyplacophora) are unusual among molluscs in dentition. They coat their teeth with iron in the form of magnetite, allowing them to scrape up algae from the rocky shore with minimal damage. But how exactly chitons manage to sequester so much iron, and deposit it so precisely, is unknown. I'm working to complete physiological and molecular analyses of this process to better understand how chitons wrangle this stress-laden, toxic metal.

Chitons evolved visual systems that are capable of spatial imaging, all without a brain with a visual processing center. How many times did vision evolve, and what can this tell us about the evolution of complex traits? Our work demonstrates that two distinct solution to spatial imaging evolved in chitons, each with more than one origin. With a rich fossil record, chitons are emerging models for understanding how path dependence (contingency) plays a critical role in dictating evolution's tape.

---