Invited Speaker  D20SY19IT10:30R8

The evolution of imperfect mimicry in hover flies (Diptera: Syrphidae)

Author(s): Sherratt TN, Penny H, Abbott K, Hassall C, Skevington J

Summary:

Although exquisite examples of the outcomes of natural selection are widely celebrated, it has long been recognized that nature’s imperfections tell us more about the process of adaptation than its perfections. Here we consider the phenomenon of imperfect mimicry and the variety of evolutionary theories that have been postulated to understand it, concentrating on hover flies (Diptera: Syrphidae). First, we review what we know about the morphological, acoustic and behavioural similarity of hover fly mimics to their putative models (bees and wasps), asking whether mimicry is extended into the UV range of the reflectance spectrum, and whether the behavioural mimics tend to be good morphological mimics. Second, we take a phylogenetic approach to quantify how frequently evolutionary transitions between model types have evolved, and what features need to evolve to facilitate mimicry of a given model type. Taken together these empirical and comparative insights allow us to rule out some theories for imperfect mimicry and provide support for others, although there is much more to do to understand the maintenance of imperfect mimicry in this species rich group.