One of the key characteristics of life is the ability to react to environmental stimuli. Sensory biologists seek to understand how organisms interface with signals, transduce the information into neural codes, interpret this neural input and initiate appropriate behavioral responses. We will explore sensory systems at the molecular, cellular and neurophysiological levels using prokaryote, invertebrate and vertebrate models. Evolutionary and comparative contexts will be used to review a broad spectrum of sensory modalities (e.g., mechanosenses). Lecture and laboratory. Prerequisite: BIOL 106 and BIOL 106L, or NEUR 201.