Shape variation between parental strains and their hybrids. (a) Whole mandible. (b, c) The two main modules. (d, e, f, g, h) The five local modules. The total morphological variation is represented in the morphological space defined by the first two axes of a principal component analysis on the superimposed coordinates of landmarks and sliding landmarks of the involved region. The percentage of variance explained by each axis is provided in brackets. The domesticus parental strain WLA is represented in red, the musculus parental strain PWK in dark blue, the F1 hybrids in light blue and the F2 hybrids in green. Each dot corresponds to one specimen. Next to each graph, the visualization of the shape change occurring along the first axis, with vectors representing the difference between the consensus shape (origin of the morphological space) and the score along the axis marked by a dark arrow.
Renaud et al. BMC Evolutionary Biology 2012 12:141 doi:10.1186/1471-2148-12-141