The capacity to learn and remember exists in most known animal species, which raises fascinating questions about the role of evolutionary processes. Logic suggests that processing and storing information for future use is likely to be fundamental for an animal’s survival and reproductive success. Foraging for food requires capacities to respond to cues that signal its availability and location, and store memories for future excursions; successful reproduction requires capacities to locate and choose a suitable mate; and, evading predators requires learning about and remembering cues associated with survival threats, such as the presence and location of predators; all of these capacities, either directly or indirectly, enhance reproductive success. Although logical deduction plays an important role in science, empirical tests are needed to confirm, in this case, evolutionary hypotheses about learning and memory. This book is about the ways in which evolutionary hypotheses inform the design of experiments on learning and memory, the empirical methods and tests that have been developed, and the knowledge derived from research programs that reveal relationships between learning, memory, and evolution. The contributors to each chapter provide unique insights into how evolution has influenced a broad array of learning and memory mechanisms across a diverse representation of invertebrate and vertebrate species.