Differing evolutionary patterns underlie convergence on elongate morphology in endemic fishes of Lake

An extensive body of research has recently demonstrated patterns of parallel and/or convergent evolution that arise from divergent natural selection pressures exerted across environmental gradients. These studies, although providing some of our best empirical evidence for natural selection, have focused on rather narrow phylogenetic scopes, more often than not comparing patterns of morphological change among closely-related taxa within a single genus. Organisms in replicated populations in these studies are often assumed to have accomplished convergence via similar underlying processes. However, such assumptions cannot be made when looking at evolution across broader phylogenetic and ecological spectra. In the present study, we assessed morphological change across a much broader scale to test whether similar evolutionary and developmental patterns underlie convergence. Specifically, we studied morphological change that has occurred in a novel lake environment (Lake Waccamaw, North Carolina, USA) where three phylogenetically-disparate fishes representing different orders have speciated and independently evolved streamlined morphologies relative to their deeper-bodied progenitors occupying nearby streams and coastal regions. Geometric morphometric analyses revealed that, although the bulk of shape change between environ-ments is similar across taxa, significant species-specific responses, concordant with differing expectations based on the ecologies of these taxa, were also found. Moreover, allometry analyses indicated that the developmental patterns underlying this change also differ across taxa. The present study provides evidence that, within