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Evolutionary significance of morphological integration of the mandibular symphysis and corpus in extant hominoids
Author(s) -
Pitirri M. Kathleen
Publication year - 2019
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2019.33.1_supplement.lb147
Subject(s) - pan paniscus , gorilla , biology , extant taxon , mandibular symphysis , evolutionary biology , hylobates , troglodytes , morphometrics , variation (astronomy) , pongo pygmaeus , symphysis , phylogenetic tree , zoology , anatomy , paleontology , biochemistry , physics , astrophysics , gene
Morphological integration refers to coordinated variation among traits that are closely related in development and/or function. Patterns of integration can offer important insight into the relationship between phenotypic traits, providing a framework to address questions of evolutionary significance. Although integrative features of the hominoid cranium have been the focus of numerous analyses, studies of integration in the hominoid mandible have received relatively less attention. Since mandibular fragments are among the most commonly preserved aspects in the hominoid fossil record, understanding patterns of morphological integration in extant hominoids has important implications for interpretations of hominoid evolution. Here, we aim to identify the pattern of integration between the shape of the mandibular corpus and symphysis in extant hominoids. To address this, we conducted a Procrutes‐based geometric morphometric analysis to quantify and analyze covariation between the outlines of the mandibular corpus and symphysis in Pongo pygmaeus , Pongo abelii , Gorilla beringei , Gorilla gorilla , Pan troglodytes and Pan paniscus . Corpus shape was quantified using three landmarks and 60 semilandmarks between M 1 and M 2 , and symphysis shape was quantified using five landmarks and 55 semilandmarks in a sample of 116 adult specimens. The relationship between corpus shape and symphysis shape was assessed using two‐block partial least squares analysis. Phylogenetic patterns of shape variation were assessed using evolutionary covariance matrices. Results of this analysis show that relatively taller, narrower symphyses with well defined superior and inferior transverse tori covary with taller, narrower corpora, while relatively shorter, wider corpora covary with wider, narrower symphyses with larger inferior transverse tori. These results also reveal taxonomic differences in patterns of integration between the corpus and the symphysis that may reflect phylogenetically significant shifts in development and/or function of the hominoid mandible. This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .