Adaptation to any environment through the course of its evolution involves the alteration of multiple traits to ensure survival, Astyanax mexicanus is a notable example of this. Some of the most notable differences between the surface and cave populations are loss of pigmentation, decreased sleep, and reduced eyes. 208 surface – cave F2 hybrids were assessed for several morphological and behavioral phenotypes. There were significant differences found between pigmented and albino individuals, raising the question of a shared genetic basis for these traits. Oculocutaneous albinism 2 (oca2) is a notable contributor to albinism in many species, including A. mexicanus. Surface fish with CRISPR mutations at oca2 confirmed a contribution of oca2 in sleep loss within albino cavefish. Further, it was determined that oca2 is under selection and possibly has a pleiotropic function, which underlies the adaptive evolution of sleep loss and albinism. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2020. / FAU Electronic Theses and Dissertations Collection

Sleep is a complex behavioral state with ramifications on multiple levels of homeostasis including bodily function, neural activity, and molecular signaling. Sleep is conserved across evolution, though significant variations in sleep duration, architecture, and behavior are found across phyla. Decoding neural processing underlying behavior, including sleep, is a fundamental aim in neuroscience, and understanding how such behavior has evolved remains largely unknown. The encompassing goal of this dissertation is to elucidate the genetic and neuronal factors at play in the evolution of sleep loss in the blind Mexican tetra, Astyanax mexicanus. To this end, the work found within will explore peripheral sensory systems regulating distinct mechanisms of sleep loss, demonstrate how evolved changes in specific hypothalamic circuits drive sleep reductions, apply computational techniques to understand whole-brain evolution, and finally, will show how the generation of transgenic tools in a novel model system can be harnessed to assist functional experimental paradigms in relation to evolution and behavior. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2020. / FAU Electronic Theses and Dissertations Collection