Fluctuating asymmetry theory can be useful in predicting the mode of selection acting on morphological traits, in particular the patterns that emerge when fluctuating asymmetry is regressed against trait length. Flat, U-shaped and positive slopes that are associated with high levels of fluctuating asymmetry are thought to be indicative of traits under sexual selection as arbitrary traits, whereas negative slopes, again with high fluctuating asymmetries, are thought to arise in traits whose expression is dependent on condition. By measuring asymmetries in the forceps and elytra of 30 earwig (Dermaptera, Forficulina) genera, we find that, although fluctuating asymmetry values are not greater in the forceps than the elytra as predicted, across species fluctuating asymmetry does increase with increasing forceps exaggeration as expected for sexually selected traits. The overall relation between forceps length and fluctuating asymmetry is flat suggesting that in general forceps are not condition-dependent traits.
|Number of pages||8|
|Journal||Proceedings of the Royal Society B: Biological Sciences|
|Publication status||Published - 23 Jan 1995|