DOI: 10.5061/dryad.j4n09
title: Data from: Rates of morphological evolution, asymmetry and morphological integration of shell shape in scallops

description: Background: Rates of morphological evolution vary across different
 taxonomic groups, and this has been proposed as one of the main drivers
 for the great diversity of organisms on Earth. Of the extrinsic factors
 pertaining to this variation, ecological hypotheses feature prominently in
 observed differences in phenotypic evolutionary rates across lineages. But
 complex organisms are inherently modular, comprising distinct body parts
 that can be differentially affected by external selective pressures. Thus,
 the evolution of trait covariation and integration in modular systems may
 also play a prominent role in shaping patterns of phenotypic diversity.
 Here we investigate the role ecological diversity plays in morphological
 integration, and the tempo of shell shape evolution and of directional
 asymmetry in bivalved scallops. Results: Overall, the shape of both valves
 and the magnitude of asymmetry of the whole shell (difference in shape
 between valves) are traits that are evolving fast in ecomorphs under
 strong selective pressures (gliders, recessers and nestling), compared to
 low rates observed in other ecomorphs (byssal-attaching, free-living and
 cementing). Given that different parts of an organism can be under
 different selective pressures from the environment, we also examined the
 degree of evolutionary integration between the valves as it relates to
 ecological shifts. We find that evolutionary morphological integration is
 consistent and surprisingly high across species, indicating that while the
 left and right valves of a scallop shell are diversifying in accordance
 with ecomorphology, they are doing so in a concerted fashion. Conclusions:
 Our study on scallops adds another strong piece of evidence that
 ecological shifts play an important role in the tempo and mode of
 morphological evolution. Strong selective pressures from the environment,
 inferred from the repeated evolution of distinct ecomorphs, have
 influenced the rate of morphological evolution in valve shape and the
 magnitude of asymmetry between valves. Our observation that morphological
 integration of the valves making up the shell is consistently strong
 suggests tight developmental pathways are responsible for the concerted
 evolution of these structures while environmental pressures are driving
 whole shell shape. Finally, our study shows that directional asymmetry in
 shell shape among species is an important aspect of scallop
 macroevolution.
description: avspecimen_coords_LLandmark coordinate data in 3D of the left valve (202 landmarks) for 933 specimens of scallops. Coordinate data are Procrustes residuals, and the average shape from 2 replicates. Specimen IDs correspond to file "ID classifier all.csv".avspecimen_coords_RLandmark coordinate data in 3D of the right valve (202 landmarks) for 859 specimens of scallops. Coordinate data are Procrustes residuals, and the average shape from 2 replicates. Specimen IDs correspond to file "ID classifier all.csv"ID classifier allClassifier file to relate specimen IDs to species. Corresponds to specimen IDs in the following files: avspecimen_coords_L_ProcLR.tps avspecimen_coords_L.csv avspecimen_coords_R_ProcLR.tps avspecimen_coords_R.csv rawspecimens_202_L_1.tps rawspecimens_202_L_2.tps rawspecimens_202_R_1.tps rawspecimens_202_R_2.tps86sp scallop treePhylogenetic tree (time calibrated) for 86 species of scallop.Spec classifier_ALLClassifier file to relate species IDs to phylogenetic tree. See Supplementary Materials Table S1 of paper for full list of species.avspecimen_coords_L_ProcLRLandmark coordinate data in 3D of the left valve (202 landmarks) for 699 specimens of scallops. Coordinate data are Procrustes residuals, from a Procrustes fit of both lefts and x-flipped rights. Specimen IDs correspond to file "ID classifier all.csv".avspecimen_coords_R_ProcLRLandmark coordinate data in 3D of the right valve (202 landmarks) for 699 specimens of scallops. Coordinate data are Procrustes residuals, from a Procrustes fit of both lefts and x-flipped rights. Specimen IDs correspond to file "ID classifier all.csv".rawspecimens_202_L_1Landmark coordinate data in 3D of the left valve (202 landmarks) for 933 specimens of scallops. Coordinate data are raw coordinates digitised from 3D surface models, first of two replicates. Specimen IDs correspond to file "ID classifier all.csv".rawspecimens_202_L_2Landmark coordinate data in 3D of the left valve (202 landmarks) for 933 specimens of scallops. Coordinate data are raw coordinates digitised from 3D surface models, second of two replicates. Specimen IDs correspond to file "ID classifier all.csv".rawspecimens_202_R_1Landmark coordinate data in 3D of the right valve (202 landmarks) for 859 specimens of scallops. Coordinate data are raw coordinates digitised from 3D surface models, first of two replicates. Specimen IDs correspond to file "ID classifier all.csv".rawspecimens_202_R_2Landmark coordinate data in 3D of the right valve (202 landmarks) for 859 specimens of scallops. Coordinate data are raw coordinates digitised from 3D surface models, second of two replicates. Specimen IDs correspond to file "ID classifier all.csv".Sherratt et al BMC Evo Bio Asymmetry Rate MSR script for the analyses of the paper.