DISSERTATION RESEARCH: Transcriptomic basis of convergent evolution in bioluminescent squid

University Of California-Santa Barbara, Santa Barbara CA

Investigators

Abstract

The phenomenon of convergent evolution fascinates scientists across disciplines. Classic examples of convergent traits, such as the camera-eyes in vertebrates and cephalopods or the wings of bats, birds and insects, remind us of the efficacy of evolution as well as the common environmental constraints shared by organisms. Yet, the extent to which convergent molecular processes drive structural convergence remains unclear. This study investigates if the number of possible ?molecular solutions? for a trait favored by natural selection is as limited as the number of structural solutions. By investigating gene expression profiles, this project addresses whether the pressure of natural selection influences genomic resourcefulness and causes the independent deployment of similar genetic pathways. Convergent forms of bioluminescence have originated often across diverse forms of life, providing an excellent system for investigating convergent evolution. Within cephalopods, a form of bioluminescence reliant on a luminous symbiotic bacterium has evolved multiple times. This study investigates if the expression profiles for genes required for the specialized organ housing these bacteria are as similar as the profiles between organs that share an evolutionary history (eyes, brain, etc.). Results of this work have important consequences for our understanding of gene expression evolution and the evolution of animal-bacteria symbiosis.