Behavioral evolution in a complex world: from social interactions to circuits

From dancing birds to singing flies, animals have evolved an astounding diversity of behaviors to attract and choose mating partners. Guided by innate preferences and aversions, the brain filters complex environments for cues and signals to successfully navigate these reproductive behaviors in appropriate spatial, temporal, and social contexts. To understand how the natural environment shapes sensory evolution and contributes to the diversification of neural circuits controlling mating behaviors, my lab studies the highly tractable nervous system of Drosophila as an inroad.

In Drosophila, courtship and mating occurs on fermenting food where many individuals congregate. Replicating this naturalistic context in the lab, we discovered striking differences in the sensory dependence of mating behaviors across species. Most notably, the host specialist Drosophila erecta requires the presence of food to engage in courtship and only mates in social groups. Harnessing the power of cross-species neurogenetics, we reveal that sexual arousal in D. erecta is uniquely gated by food odors that switch the valence of visual stimuli driving courtship. This provides a possible neural mechanism underlying the environmental modulation of reproductive behaviors, highlighting how social behaviors are shaped by the natural environments in which they evolve.