My primary interest is in the evolution of an exaggerated sexual trait, male eyespan, in stalk-eyed flies. Current evolutionary studies are focussed on whether male eyespan has condition-dependent expression and acts as a signal of male quality. Developmental genetic techniques are being used to identify and compare expression patterns of genes involved in regulating eyestalk development for several species varying in their degree of eyespan exaggeration. Transgenic methods for analysing gene function are under development. Stalk-eyed flies show very high rates of matings with the scope for conflict between the sexes. To evaluate this, we are identifying seminal fluid proteins and their fitness effects. My secondary interest is in evolutionary consequences of inbreeding in fruitflies. We assess changes in morphological and fitness traits after bottlenecks and evaluate whether natural selection can 'purge' deleterious recessive alleles. Such purging is potentially significant for endangered populations because some may be restored to high fitness.