The study of islands as model systems has played an important role in the development of evolutionary and ecological theory. The 50th anniversary of MacArthur and Wilson's (December 1963) article, 'An equilibrium theory of insular zoogeography', was a recent milestone for this theme. Since 1963, island systems have provided new insights into the formation of ecological communities. Here, building on such developments, we highlight prospects for research on islands to improve our understanding of the ecology and evolution of communities in general. Throughout, we emphasise how attributes of islands combine to provide unusual research opportunities, the implications of which stretch far beyond islands. Molecular tools and increasing data acquisition now permit reassessment of some fundamental issues that interested MacArthur and Wilson. These include the formation of ecological networks, species abundance distributions, and the contribution of evolution to community assembly. We also extend our prospects to other fields of ecology and evolution -understanding ecosystem functioning, speciation and diversification -frequently employing assets of oceanic islands in inferring the geographic area within which evolution has occurred, and potential barriers to gene flow. Although island-based theory is continually being enriched, incorporating non-equilibrium dynamics is identified as a major challenge for the future.

Sexual recognition through wing-beat frequency matching was first demonstrated in Toxorhynchites brevipalpis, where wing-beat frequencies of males and females are similar. Here we show frequency matching in Culex quinquefasciatus, where the wing-beat frequencies of males and females differ considerably. The wing-beat frequencies converge not on the fundamental but on the nearest shared harmonic (usually female's third and male's second). Frequencies in this range are, however, too high to elicit phasic sensory-neural responses from the Johnston's organ (JO) or to drive the mosquito's motor neurons. Potential cues for frequency matching are difference tones produced by nonlinear mixing of male and female flight tones in the vibrations of the mosquito's antennae. Receptor potentials and neural-motor activity were recorded in response to difference tones produced when a mosquito was stimulated simultaneously by two tones at frequencies outside the phasic response range of the JO but within range of the antennal vibrations. We demonstrate sexual recognition through matching of flight-tone harmonics in Culex mosquitoes and suggest that difference tones are used as an error signal for frequency matching beyond the frequency range of the JO's sensory-neural range. This is the first report of acoustic distortion being exploited as a sensory cue, rather than existing as an epiphenomenon.