Fundamental questions in biology include: How do complex traits, such as eyes, evolve through changes in underlying sub-components? What are the transitional steps in function that link simple light-sensitive structures and complex image-forming eyes? The studies supported by this award use chitons (Mollusca: Polyplacophora) in an integrative research approach to ask how and why eyes evolve. Specifically, the proposal addresses: 1) changes in genotype associated with the origin of new light-interacting structures and 2) relationships between new light-interacting structures and new light-influenced behaviors. Integrative research on chitons will help advance the field of biomaterials. Studying the aragonite lenses of chitons will help researchers learn how animals build precisely shaped structures through the process of biomineralization. Studying the origin of eyes in chitons will also help counter popular misconceptions about evolution by demonstrating how complex traits evolve through stepwise processes. Undergraduate and graduate training, as well as public outreach efforts are also integrated into this project.
The research objectives for this award follow the unique sensory organs (aesthetes) embedded in chiton shell plates: photoreceptors, eyespots, and eyes (with aragonite lenses). Specifically, the award supports studies to: (1) Identify the molecular components responsible for light-detection in eyeless chitons and establish the visually-influenced behaviors displayed by these animals; (2) Characterize the pigments and pigment-producing genes associated with the eyespots of certain chitons and establish the light-influenced behaviors unique to these species; and (3) Investigate the molecular components that confer spatial vision in chitons with eyes and identify genes that may be associated with the development of their aragonite lenses. Results from the studies will be published in peer-reviewed journals and disseminated at scientific meetings.
