Data from: Using geometric morphometric visualizations of directional selection gradients to investigate morphological differentiation

Researchers studying extant and extinct taxa are often interested in identifying the evolutionary processes that have lead to the morphological differences among the taxa. Ideally, one could distinguish the influences of neutral evolutionary processes (genetic drift, mutation) from natural selection, and in situations for which selection is implicated, identify the targets of selection. The directional selection gradient is an effective tool for investigating evolutionary process, because it can relate form (size and shape) differences between taxa to the variation and covariation found within taxa. However, although most modern morphometric analyses use the tools of geometric morphometrics (GM) to analyze landmark data, to date, selection gradients have mainly been calculated from linear measurements. To address this methodological gap, here we present a GM approach for visualizing and comparing between-taxon selection gradients with each other, associated difference vectors, and "selection" gradients from neutral simulations. To exemplify our approach, we use a dataset of 347 three-dimensional landmarks and semilandmarks recorded on the crania of 260 primate specimens (112 humans, 67 common chimpanzees, 36 bonobos, 45 gorillas). Results on this example dataset show how incorporating geometric information can provide important insights into the evolution of the human braincase, and serve to demonstrate the utility of our approach for understanding morphological evolution.WeaverGunz_260ind_347slidlms_logCSThis text file contains the example dataset used by Weaver and Gunz in their Evolution publication. The rows correspond to 260 different primate specimens, with the specimen number and species name given by the rows of "WeaverGunz_4species_labels.txt" (e.g., row 4 in the labels file corresponds to row 4 in the dataset file). The full species names are given in Table 3 of the publication. The columns contain the Procrustes fit and slid landmarks/semilandmarks and the log Centroid size. Columns 1-3 contain the x, y, and z coordinates of the 1st landmark/semilandmark, columns 4-6 contain the x, y, and z coordinates of the 2nd landmark/semilandmark, and so on, up to the 1041st column (z coordinate of the 347th landmark/semilandmark). The 1042nd column contains the log Centroid Size. The landmarks/semilandmarks are ordered following Table 1 in the publication.WeaverGunz_4species_labelsThis text file contains the labels for the example dataset used by Weaver and Gunz in their Evolution publication. See description of "WeaverGunz_260ind_347slidlms_logCS.txt" for more information.WeaverGunz_neutral_simulationsThis text file contains Matlab code for simulating the "selection" gradients from neutral divergence used by Weaver and Gunz in their Evolution publication. The code is meant to be used with the "WeaverGunz_260ind_347slidlms_logCS.txt" dataset file and the "WeaverGunz_4species_labels.txt" labels file. Refer to the publication for details about the methods.WeaverGunz_neutBetaUnit100This text file contains 100 simulated "selection" gradients from neutral divergence, which were produced by the Matlab code in the "WeaverGunz_neutral_simulations.m" file, using the methods described by Weaver and Gunz in their Evolution publication. Each row corresponds to a single "selection" gradient from neutral divergence. See description of "WeaverGunz_260ind_347slidlms_logCS.txt" for an explanation of the columns