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.