A new fully automated approach for aligning and comparing shapes.

Published

Journal Article

Three-dimensional geometric morphometric (3DGM) methods for placing landmarks on digitized bones have become increasingly sophisticated in the last 20 years, including greater degrees of automation. One aspect shared by all 3DGM methods is that the researcher must designate initial landmarks. Thus, researcher interpretations of homology and correspondence are required for and influence representations of shape. We present an algorithm allowing fully automatic placement of correspondence points on samples of 3D digital models representing bones of different individuals/species, which can then be input into standard 3DGM software and analyzed with dimension reduction techniques. We test this algorithm against several samples, primarily a dataset of 106 primate calcanei represented by 1,024 correspondence points per bone. Results of our automated analysis of these samples are compared to a published study using a traditional 3DGM approach with 27 landmarks on each bone. Data were analyzed with morphologika(2.5) and PAST. Our analyses returned strong correlations between principal component scores, similar variance partitioning among components, and similarities between the shape spaces generated by the automatic and traditional methods. While cluster analyses of both automatically generated and traditional datasets produced broadly similar patterns, there were also differences. Overall these results suggest to us that automatic quantifications can lead to shape spaces that are as meaningful as those based on observer landmarks, thereby presenting potential to save time in data collection, increase completeness of morphological quantification, eliminate observer error, and allow comparisons of shape diversity between different types of bones. We provide an R package for implementing this analysis.

Full Text

Duke Authors

Cited Authors

  • Boyer, DM; Puente, J; Gladman, JT; Glynn, C; Mukherjee, S; Yapuncich, GS; Daubechies, I

Published Date

  • January 2015

Published In

Volume / Issue

  • 298 / 1

Start / End Page

  • 249 - 276

PubMed ID

  • 25529243

Pubmed Central ID

  • 25529243

Electronic International Standard Serial Number (EISSN)

  • 1932-8494

International Standard Serial Number (ISSN)

  • 1932-8486

Digital Object Identifier (DOI)

  • 10.1002/ar.23084

Language

  • eng