Evolutionary trajectories of Auguritidae and Pinacitidae in the morphological space defined by the three characters involved in the case of parallel evolution. A, Statistical evaluation of the parallel evolution by means of the trajectory approach of . Plot of the first and second principal components estimated from the correlation matrix for auguritids and pinacitids based on the three standardized characters UWI, Dmx, and NLb. Statistical evaluation of the parallel evolution is indicated with and without the auguritid outlier taxon Weyeroceras angustus (dashed line). Parameters with more than minimal support are in bold. There are no significant differences in magnitude and direction of the trajectories, but they are different in shape. B, Statistical evaluation of the parallel evolution by means of the regression approach of . The phylogenetic trajectory of each lineage is fitted by a linear total least square regression. The statistical evaluation is indicated without the auguritid outlier taxon. The p-value of the test (p = 0.0197) is low, but the hypothesis of parallel trajectories could not be rejected by the permutation test.
Monnet et al. BMC Evolutionary Biology 2011 11:115 doi:10.1186/1471-2148-11-115