When a species invades a new habitat, or its existing environment changes, its perception of the world is likely to change because environments differ in the physical properties on which the senses depend. This has profound implications because senses determine how animals find and discriminate between mates or prey, avoid potential predators, and locate better microhabitats. For example, changed visual environments will cause predictable evolutionary changes in visual contrast to predator and prey, in turn causing evolutionary changes in visually based mate and prey choice, evolution in microhabitat selection (which affects the light environment and hence visual contrast) and evolution in the visual system. I propose to test a series of predictions about evolution of these four suites of traits by (1) experimental evolution experiments over 15 generations in laboratory guppy populations under three different light environments to test predictions about changes in male colour patterns, female preferences for male patterns, and changes in the guppy colour vision system and (2) 15 generation guppy evolution experiments to test for co-option of prey-search cues as mate choice cues and evolution of the other trait suites The EU has 80% of the world's Sensory Ecologists and I will consolidate and make the EU lead obvious by encouraging collaborations between disparate groups and encouraging young scientists.