Data from: The utility of cranial ontogeny for phylogenetic inference: a case study in crocodylians using geometric morphometrics

Main Authors: Watanabe, Akinobu, Slice, Dennis E.
Format: info dataset Journal
Terbitan: , 2014
Subjects:
Online Access: https://zenodo.org/record/4989490
Daftar Isi:
  • The degree to which the ontogeny of organisms could facilitate our understanding of phylogenetic relationships has long been a subject of contention in evolutionary biology. The famed notion that 'ontogeny recapitulates phylogeny' has been largely discredited, but there remains an expectation that closely related organisms undergo similar morphological transformations throughout ontogeny. To test this assumption, we used three-dimensional geometric morphometric methods to characterize the cranial morphology of 10 extant crocodylian species and construct allometric trajectories that model the post-natal ontogenetic shape changes. Using time-calibrated molecular and morphological trees, we employed a suite of comparative phylogenetic methods to assess the extent of phylogenetic signal in these trajectories. All analyses largely demonstrated a lack of significant phylogenetic signal, indicating that ontogenetic shape changes contain little phylogenetic information. Notably, some Mantel tests yielded marginally significant results when analysed with the morphological tree, which suggest that the underlying signal in these trajectories is correlated with similarities in the adult cranial morphology. However, despite these instances, all other analyses, including more powerful tests for phylogenetic signal, recovered statistical and visual evidence against the assumption that similarities in ontogenetic shape changes are commensurate with phylogenetic relatedness and thus bring into question the efficacy of using allometric trajectories for phylogenetic inference.
  • Coordinate data of crocodylian crania (pre-superimposed)Coordinate data of 78 three-dimensional landmarks from 204 cranial specimens of 10 extant crocodylian species. All specimens, with the exception of Gavialis and Tomistoma, are from non-captive individuals. Raw coordinate data were collected with a G2 Microscribe digitzer (Immersion Corporation, CA, USA) by the principal author (A.W.). The coordinate data is in NTSYS format, in which the digitized specimens have been aligned according to PC axes (x axis = anteroposterior; y axis = mediolateral; z axis=dorsoventral), but still retain their original size. The coordinate points, therefore, have not been subjected to generalized Procrustes superimposition, allowing the user to calculate centroid size. Specimens are labeled in the file with species ID (first three letters of generic and specific names; e.g., allmis = Alligator mississippiensis) followed by their respective institutional specimen number. Please refer to the main article and associated supplementary text file for description of landmarks and additional information on the acquisition and treatment of data.WatanabeSlice_JEB_PreGPA.ntsPermuTreePython program for performing a permutational regression analysis on trees. It takes a NEWICK string file and a CSV file of a single continuous variable and tests for significant correlation between phenotypic and phylogenetic distances. Please note that this script was written in Python version 2.7, thus some commands may not run properly (e.g., print function). In addition, the script requires the tree.py module to run, which can be downloaded through Peter Beerli's website (see README), as well as matplotlib and scipy Python packages.permutree.pyTree Comparison Test (SPR)Script written for the TNT phylogenetic program for testing the significant of topological similarity between two trees relative to randomly generated tree topologies. After placing the script in the same directory as TNT, analysis is performed by running "comptreeSPR <# iterations>" in the command line.comptreeSPR.run