Phylogeny, Diet, and Cranial Integration in Australodelphian Marsupials

Jean-Nicolas Volff,Anjali Goswami

doi:10.1371/journal.pone.0000995

Jean-Nicolas Volff, Anjali Goswami

Open Access

https://doi.org/10.1371/journal.pone.0000995

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Journal: PLoS ONE	Publication Date: Oct 3, 2007
Citations: 75	License type: CC BY 4.0

Affiliation: University of Chicago, Field Museum of Natural History

Abstract

Studies of morphological integration provide valuable information on the correlated evolution of traits and its relationship to long-term patterns of morphological evolution. Thus far, studies of morphological integration in mammals have focused on placentals and have demonstrated that similarity in integration is broadly correlated with phylogenetic distance and dietary similarity. Detailed studies have also demonstrated a significant correlation between developmental relationships among structures and adult morphological integration. However, these studies have not yet been applied to marsupial taxa, which differ greatly from placentals in reproductive strategy and cranial development and could provide the diversity necessary to assess the relationships among phylogeny, ecology, development, and cranial integration. This study presents analyses of morphological integration in 20 species of australodelphian marsupials, and shows that phylogeny is significantly correlated with similarity of morphological integration in most clades. Size-related correlations have a significant affect on results, particularly in Peramelia, which shows a striking decrease in similarity of integration among species when size is removed. Diet is not significantly correlated with similarity of integration in any marsupial clade. These results show that marsupials differ markedly from placental mammals in the relationships of cranial integration, phylogeny, and diet, which may be related to the accelerated development of the masticatory apparatus in marsupials.

Highlights

The correlated evolution of traits is a fundamental issue in evolutionary biology, with great importance for understanding morphological evolution and the generation of morphological diversity [1,2,3]
Phylogeny and ecology are of particular interest, as they have been correlated with similarity of cranial integration in the placental clades Primates [13,15,16] and Carnivora [11]
Neither dietary similarity matrix (DSM) nor dietary similarity residual matrix (DSRM) were significantly correlated with similarity in morphological integration in any of the clades examined in this study (Fig. 3, Table 3)

Summary

Introduction

The correlated evolution of traits is a fundamental issue in evolutionary biology, with great importance for understanding morphological evolution and the generation of morphological diversity [1,2,3]. Integration of functionally or developmentally-related traits can influence morphological evolution in many ways, from constraining the variability of individual traits to facilitating transformations of functional sets [1,2,3,4,5,6,7,8,9,10]. Despite this importance to morphological evolution, trait integration has been overlooked in most morphological analyses. Phylogeny and ecology are of particular interest, as they have been correlated with similarity of cranial integration in the placental clades Primates [13,15,16] and Carnivora [11]

Methods

Results

Conclusion