Cited by 1,109Morphological variations and asymmetryAnimal Behavior and ReproductionComparative Animal Anatomy Studies

Shape analysis of symmetric structures: quantifying variation among individuals and asymmetry

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Klingenberg, Christian Peter, Barluenga, Marta, Meyer, Axel·2002·Evolution

Abstract

Morphometric studies often consider parts with internal left-right symmetry, for instance, the vertebrate skull. This type of symmetry is called object symmetry and is distinguished from matching symmetry, in which two separate structures exist as mirror images of each other, one on each body side. We explain a method for partitioning the total shape variation of landmark configurations with object symmetry into components of symmetric variation among individuals and asymmetry. This method is based on the Procrustes superimposition of the original and a reflected copy of each landmark configuration and is compatible with the two-factor ANOVA model customary in studies of fluctuating asymmetry. We show a fully multivariate framework for testing the effects in the two-factor model with MANOVA statistics, which also applies to shapes with matching symmetry. We apply the new methods in a small case study of pharyngeal jaws of the Neotropical cichlid fish Amphilophus citrinellus. The analysis revealed that the symmetric component of variation in the pharyngeal jaws is dominated by the contrast between two alternative trophic morphs in this species and that there is subtle but statistically significant directional asymmetry. Finally, we provide some general recommendations for morphometric studies of symmetric shapes.

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Crossref · 10.1111/j.0014-3820.2002.tb00117.x

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  • Human skulls exhibit object symmetry (the axis of symmetry passes through mid-plane, and the left and right halves are mirror images of each other).

    “Human skulls exhibit object symmetry (i.e. the axis of symmetry passes through mid-plane, and hence the left and right halves are mirror images of each other), therefore the recommendations of [100,101] were followed.”

    From Morphological consequences of artificial cranial deformation: Modularity and integration (2020) · cites this paper as [101]

    In “Matching Symmetry and Object Symmetry,” the paper identifies the vertebrate skull as having an internal plane of symmetry. The Figure 1 caption says the left and right halves are mirror images **with the exception of asymmetries**, and the same section notes that real organisms are hardly ever perfectly symmetric. The claim omits that qualification. (LLM, conf=0.84)

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Authors
Klingenberg, C. P., Barluenga, M., & Meyer, A.
Affiliations
University of Konstanz (DE)
Venue
Evolution
Published
2002-10
Volume
56
Issue
10
Pages
1909-1920
ISSN
  • 0014-3820 (ISSN-L)
  • 1558-5646
OpenAlex
W2114574345
Cited by
1,109
References
67
Citations by year
2026: 44 · 2025: 54 · 2024: 59 · 2023: 55 · 2022: 62 · 2021: 69 · 2020: 97 · 2019: 82 · 2018: 87 · 2017: 64 · 2016: 74 · 2015: 44 · 2014: 76 · 2013: 50 · 2012: 39
FWCI
11.89
Type
journal article
Language
en
Open access
Locations
  • Evolution (publishedVersion)
  • PubMed (publishedVersion)
  • Research Explorer (The University of Manchester) (publishedVersion)
  • KOPS (University of Konstanz) (submittedVersion, cc-by-nc-nd)
  • BioOne Complete (BioOne) (submittedVersion)
Topics
  • Physical Sciences › Mathematics › Geometry and Topology › Morphological variations and asymmetry
  • Life Sciences › Agricultural and Biological Sciences › Ecology, Evolution, Behavior and Systematics › Animal Behavior and Reproduction
  • Health Sciences › Medicine › Urology › Comparative Animal Anatomy Studies
Keywords
object symmetry, fluctuating asymmetry, Procrustes superimposition, two-factor ANOVA, directional asymmetry, pharyngeal jaw, Amphilophus citrinellus, cichlid fish
MeSH terms
Analysis of Variance, Animals, Biometry, Humans, Mathematics, Models, Anatomic, Software, Body Patterning, Cichlids

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