Morphological integration of anatomical, developmental, and functional postcranial modules in the crab‐eating macaque (Macaca fascicularis)

Abstract

The results suggest that morphometrically complex modules tend to be less integrated than simple limb bones, irrespective of the number of available traits. However, differences in integration of the fore- and hindlimb more likely reflects the multitude of locomotory, feeding, and social functions involved. It remains to be tested whether patterns of integration identified here are primate universals, and to what extent they vary depending on phylogenetic or functional factors.

Phenotypic integration in feliform carnivores: Covariation patterns and disparity in hypercarnivores versus generalists

“…Phenotypic integration and modularity can be investigated at different levels of organization, from modules within one structure to phenotypic-genetic integration, through both exploratory and confirmatory analyses (e.g., Klingenberg 2009;Goswami and Polly 2010;Klingenberg, 2013Klingenberg, , 2014Goswami et al 2014;Goswami and Finarelli 2016). Although exploratory studies focus on identifying modules without a priori hypothesis (Cheverud 1982;Bookstein 2015;Goswami and Finarelli 2016;Randau et al 2019), confirmatory analyses aim to test patterns and strength of covariations between different modules recovered from exploratory approaches (Bookstein et al 2003;Goswami 2006;Mitteroecker and Bookstein 2007;Klingenberg, 2008Klingenberg, , 2009Goswami and Polly 2010;Adams 2016), or defined on an anatomical, developmental, or functional basis (see Willmore et al 2006;Esteve-Altava et al 2013;Martín-Serra et al 2015;Randau and Goswami 2017a;Conaway et al 2018;Martín-Serra et al 2018;Bon et al 2020; Bardua et al 2019;Fabre et al 2020).…”

Ontogenetic changes in magnitudes of integration in the macaque skull

“…Integration scores for these skull modules were calculated using the integration coefficient of variation (ICV) of eigenvalues based on the variance/covariance (V/CV) matrix of interlandmark distances (Conaway, Schroeder, & von Cramon‐Taubadel, 2018; Shirai & Marroig, 2010). In primate taxa, some interlandmark distances (traits) may be sexually dimorphic (Fleagle, 2013).…”

“…The Mann-Whitney U tests between the skull as T A B L E 1 Description of age and sex of M. fascicularis specimens used in this study and the individual skull modules determined whether specific skull modules show higher ICV scores than expected relative to the entire skull's ICV scores using the same interlandmark distances from specific age group. ICV scores of the skull as a whole were regarded as constituting the integration of a "random" set of traits drawn from across the skull(Conaway et al, 2018). This means that the ICV scores of the skull as a whole were used as the baseline to examine whether a priori determined or hypothesized skull modules are "really" integrated in terms of their magnitudes of integration.Thus, significantly lower or non-significantly different ICV scores of each skull module compared with the skull as a whole indicates that a specific skull module is not distinctly integrated in terms of magnitude of integration.…”

Multivariate morphometrics, quantitative genetics, and neutral theory: Developing a “modern synthesis” for primate evolutionary morphology

“…First, there is a growing realization within evolutionary anthropology that the primate skeleton represents a complex, integrated system with varying levels of modularity based on genetic, developmental, and functional factors . Therefore, there is an urgent need to assimilate the multivariate form of different aspects of the skeleton (cranium and postcranium) in evolutionary studies so that we can build a better understanding of what the morphological units of evolution might be.…”

“…First, there is a growing realization within evolutionary anthropology that the primate skeleton represents a complex, integrated system with varying levels of modularity based on genetic, developmental, and functional factors. 54,97 Therefore, there is an urgent need to assimilate the multivariate form of different aspects of the skeleton (cranium and postcranium) in evolutionary studies so that we can build a better understanding of what the morphological units of evolution might be. In recognizing that developmental gene complexes direct the basic bauplan patterning of the skeleton, it is becoming clear that evolutionary forces (particularly natural selection) acting on one region of the skeleton can have a correlated and unexpected knock-on effect on another skeletal region.…”