Fluctuating paradigm

A prominent paradigm in evolutionary biology over the last ten years has been the role of fluctuating asymmetry in sexual selection. Fluctuating asymmetry in bilaterally paired traits, and in particular sexual traits, has been proposed to be a reliable indicator of individual quality and the focus of selection through sexual competition and attractiveness. We surveyed the literature on fluctuating asymmetry and sexual selection and found a marked chronological decline in the proportion of studies supporting the paradigm through the 1990s. Our data are supported by an independent meta-analysis of the literature. The data conform with the notion of a scientific revolution in which the early phase of a paradigm change is characterized by a publication bias, a less critical approach to research, or both. The patterns we observe in the fluctuating asymmetry literature suggest caution in drawing general conclusions from meta-analyses conducted before revolutions hare settled.