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Updated: Jul 10, 2026
04:32
Dissection, MicroCT Scanning and Morphometric Analyses of the Baculum
Published on: March 19, 2017
Traditional characters and Procrustes-aligned landmark data: a sensitivity analysis in morphological data type
Nicholas W Post1,2,3, Santiago A Catalano4,5, Sergio Almécija2,6,7
1Richard Gilder Graduate School, American Museum of Natural History, New York, NY, USA.
Summary
Geometric morphometric (GM) data significantly impacts phylogenetic inference when combined with discrete traits. Adjusting the weight of GM data influences evolutionary tree topology, especially for fossil hominins with limited discrete character information.
Area of Science:
- Evolutionary Biology
- Paleontology
- Phylogenetics
Background:
- Total-evidence phylogenetic analyses integrate diverse data types, posing challenges in assessing partition influence.
- Morphological studies combining discrete characters and geometric morphometrics (GM) face unique difficulties due to differing data structures, scales, and completeness.
Purpose of the Study:
- To investigate how varying the weight of cranial landmark configurations relative to craniodental discrete characters affects phylogenetic tree length and topology.
- To evaluate the impact of geometric morphometric data on parsimony-based phylogenetic inference in primates and fossil hominins.
Main Methods:
- Performed iterative weighting series in parsimony analyses, varying the weight of geometric morphometric (GM) landmark data against discrete craniodental characters.
- Conducted analyses including all available data and a subset excluding discrete characters for specific fossil hominins, relying solely on GM data.
Main Results:
- Increasing GM weight resulted in stepwise topological changes, not continuous shifts, with repeated identical most parsimonious trees observed.
- Geometric morphometric data's contribution to total tree length increased nonlinearly, indicating diminishing returns.
- Topological shifts were concentrated among fossil hominins, particularly when they were represented solely by heavily weighted landmark data.
Conclusions:
- Geometric morphometric (GM) data can substantially influence parsimony-based phylogenetic inference.
- The impact of GM data is strongly contingent upon weighting schemes and the distribution of missing data across taxa.
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