scholarly journals Sexual Dimorphism and Morphological Modularity in Acanthoscelides obtectus (Say, 1831) (Coleoptera: Chrysomelidae): A Geometric Morphometric Approach

Insects ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 350
Author(s):  
Sanja Budečević ◽  
Uroš Savković ◽  
Mirko Đorđević ◽  
Lea Vlajnić ◽  
Biljana Stojković
Keyword(s):  
Sexual Dimorphism ◽  
Reproductive Function ◽  
Morphological Integration ◽  
Stabilizing Selection ◽  
Shape Variation ◽  
Acanthoscelides Obtectus ◽  
Geometric Morphometric ◽  
Size And Shape ◽  
Acanthoscelides Obtectus Say ◽  
Functional Hypothesis

Sexual dimorphism and specific patterns of development contribute in a great manner to the direction and degree of the sexual differences in body size and shape in many insects. Using a landmark-based geometric morpohometrics approach, we investigated sex-specific morphological size and shape variation in the seed beetle, Acanthoscelides obtectus. We also tested the functional hypothesis of the two morphological modules—thorax and abdomen in both sexes. Female-biased sexual dimorphism in size was shown, while differences in shape were reflected in the wider thorax and abdomen and shorter abdomen in females in comparison to males. The functional hypothesis of a two-module body was confirmed only in females before correction for size, and in both sexes after the allometry correction. Our results indicate that reproductive function has the central role in forming the patterns of modularity. We hypothesize that high morphological integration of the abdomen in females results from intense stabilizing selection, while the more relaxed integration in males is driven by the higher intensity of sexual selection.

scholarly journals Intraspecific morphological variation of the scorpionfly Dicerapanorpa magna (Chou) (Mecoptera: Panorpidae) based on geometric morphometric analysis of wings

2016 ◽  
Vol 85 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Mei Liu ◽  
Na Ma ◽  
Bao-Zhen Hua
Keyword(s):  
Sexual Dimorphism ◽  
Morphometric Analysis ◽  
Divergence Time ◽  
Wing Size ◽  
Shape Variation ◽  
Geometric Morphometric ◽  
Size And Shape ◽  
Geometric Morphometric Analysis ◽  
Different Populations ◽  
Intraspecific Morphological Variation

Wing shape variation was investigated between the sexes and among four populations of the scorpionfly Dicerapanorpa magna (Chou, 1981) endemic to the Qin-Ba Mountains area, China through the landmark-based geometric morphometric approach. The results show that sexual dimorphism exists both in wing size and shape in D. magna. Significant differences exist in female wing size and shape among D. magna populations. The possible reasons of the wing variation are discussed based on the divergence time of D. magna in combination with the tectonic and climatic events in the Qin-Ba Mountains during the late Miocene-Pleistocene period. Whether reproductive isolation exists between different populations needs further research.

The Cheilosia canicularis group (Diptera: Syrphidae): species delimitation and evolutionary relationships based on wing geometric morphometrics

Zootaxa ◽  
2008 ◽  
Vol 1825 (1) ◽  
pp. 40 ◽  
Author(s):  
JASMINA LUDOŠKI ◽  
LJUBINKA FRANCUSKI ◽  
ANTE VUJIĆ ◽  
VESNA MILANKOV
Keyword(s):  
Sequence Data ◽  
Balkan Peninsula ◽  
Wing Shape ◽  
Canonical Variate ◽  
Wing Size ◽  
Shape Variation ◽  
Geometric Morphometric ◽  
Mahalanobis Distances ◽  
Size And Shape ◽  
Upgma Cluster Analysis

A landmark-based geometric morphometric approach was used to assess differences in the size and shape of wing among/within three species of the Cheilosia canicularis group (Diptera: Syrphidae): C. canicularis, C. himantopus and C. orthotricha. Wing size and shape variation was observed from 25, 176 and 41 specimens of C. canicularis, C. himantopus and C. orthotricha, respectively, collected from six localities on the Balkan Peninsula. Significant differences in wing size were obtained among the analysed species and canonical variate analysis showed that wing shape was sufficiently different to allow the correct classification of 73% individuals of C. canicularis, 80% of C. orthotricha and 94% of C. himantopus, and clear delimitation of the species pairs C. canicularis/C. orthotricha and C. himantopus/C. orthotricha. In all analysed species, the consistent sex dimorphism in wing shape was observed indicating that female specimens had shorter and broader wings than males. The UPGMA cluster analysis based on squared Mahalanobis distances revealed close accordance with previously published phylogenetic relationships of these species indicated by allozyme and DNA sequence data analysis. Our results suggested that wing parameters contain useful information in quantification phenotypic variation and identification of species in this challenging group for taxonomy and systematics.

A Geometric Morphometric Assessment of Hand Shape and Comparison to the 2D:4D Digit Ratio as a Marker of Sexual Dimorphism

2013 ◽  
Vol 16 (2) ◽  
pp. 590-600 ◽  
Author(s):  
Paul G. Sanfilippo ◽  
Alex W. Hewitt ◽  
Jenny A. Mountain ◽  
David A. Mackey
Keyword(s):  
Sexual Dimorphism ◽  
Geometric Morphometrics ◽  
Shape Analysis ◽  
Twin Studies ◽  
Analytical Techniques ◽  
Shape Variation ◽  
Geometric Morphometric ◽  
Hand Shape ◽  
Physical Traits ◽  
Biological Shape

Twin studies are extremely useful for investigating hypotheses of genetic influence on a range of behavioral and physical traits in humans. Studies of physical traits, however, are usually limited to size-related biological characteristics because it is inherently difficult to quantify the morphological counterpart – shape. In recent years, the development of geometry-preserving analytical techniques built upon multivariate statistical methodologies has produced a new discipline in biological shape analysis known as geometric morphometrics. In this study of hand shape analysis, we introduce the reader already familiar with the field of twin research to the potential utility of geometric morphometrics and demonstrate the cross-discipline applicability of methods. We also investigate and compare the efficacy of the 2D:4D ratio, a commonly used marker of sexual dimorphism, to the fully multivariate approach of shape analysis in discriminating between male and female sex. Studies of biological shape variation utilizing geometric morphometric techniques may be completed with software freely available on the Internet and time invested to master the small learning curve in concepts and theory.

A geometric morphometric analysis of hominin upper premolars. Shape variation and morphological integration

2011 ◽  
Vol 61 (6) ◽  
pp. 688-702 ◽  
Author(s):  
Aida Gómez-Robles ◽  
María Martinón-Torres ◽  
José María Bermúdez de Castro ◽  
Leyre Prado-Simón ◽  
Juan Luis Arsuaga
Keyword(s):  
Morphometric Analysis ◽  
Morphological Integration ◽  
Shape Variation ◽  
Geometric Morphometric ◽  
Geometric Morphometric Analysis

scholarly journals Intraspecific Morphological Variation in Two Common Marine Fish Species from South Africa

2013 ◽  
Vol 6 (1) ◽  
pp. 87-91 ◽  
Author(s):  
Eric Mattson ◽  
Mark C. Belk
Keyword(s):  
Sexual Dimorphism ◽  
Marine Fish ◽  
Fish Species ◽  
Morphological Variation ◽  
Environmental Gradients ◽  
Human Consumption ◽  
Shape Variation ◽  
Geometric Morphometric ◽  
Feeding Niche ◽  
Intraspecific Morphological Variation

Intraspecific morphological variation in fish is typically associated with sexual dimorphism, or one of three common environmental gradients: variation in intensity of predation, variation in water velocity, or variation in feeding niche. The preponderance of examples of environment-associated morphological variation within fish species has been documented in freshwater systems. It is not clear whether environment-associated intraspecific morphological variation is less common in marine fishes or whether there has just been a lack of investigation. We used geometric morphometric analysis to quantify shape variation in two species of South African marine fish commonly harvested for human consumption, Pterogymnus laniarius (panga), and Argyrosomus inodorus (silver kob). Neither species exhibited significant sexual dimorphism, but both species exhibited significant intraspecific morphological variation. This variation appears consistent with patterns expected from variation along the benthic-pelagic feeding niche continuum.

scholarly journals Sexual dimorphism of the mandibular conformational changes in aging human adults: A multislice computed tomographic study by geometric morphometrics

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0253564
Author(s):  
Leonor Costa Mendes ◽  
Julien Delrieu ◽  
Claudia Gillet ◽  
Norbert Telmon ◽  
Delphine Maret ◽  
...  
Keyword(s):  
Sexual Dimorphism ◽  
Conformational Changes ◽  
Sexually Dimorphic ◽  
Shape Variation ◽  
Geometric Morphometric ◽  
Computed Tomographic ◽  
Age Related ◽  
Human Adults ◽  
Geometric Morphometric Analysis ◽  
Shape Changes

The aging process has an impact on mandibular bone morphology and can therefore affect shape sexual dimorphism. Understanding the effect of senescence on mandibular shape changes is particularly important to correctly estimate the sex of an individual and predict age-related conformational modifications. The purpose of this study was to assess age-related changes in mandibular shape and sexual dimorphism. The study sample comprised 160 Multi Slice Computed Tomography examinations of individuals aged 40 to 79 years. Geometric morphometric analysis of fourteen osteometric landmarks was used to examine sexual dimorphism and patterns of mandibular shape variation with age. Results showed that mandibular sexual dimorphism of shape remained significant with aging. Conformational changes occurred between 50 and 70 years and were different for male and female individuals. Females presented earlier and more marked age-related shape changes than males. These observations suggest that mandibular senescence is a sexually dimorphic process since its onset, rate, and the areas subjected to conformational changes differ from male to female individuals. Senescence-related changes present substantial variability, and further investigation is required to determine precisely the age that marks their onset.

No functional sexual dimorphism in Minorcan horse assessed by geometric morphometric methods

2015 ◽  
Vol 56 ◽  
pp. 91-95 ◽  
Author(s):  
Pere M. Parés-Casanova ◽  
C. Allés
Keyword(s):  
Sexual Dimorphism ◽  
Lateral View ◽  
Geometric Morphometric ◽  
Male And Female ◽  
Size And Shape ◽  
Morphometric Methods ◽  
Nw Mediterranean ◽  
Nw Mediterranean Sea ◽  
Age Range ◽  
Shape And Size

SummaryThe existence of sexual dimorphism in the Minorcan horse, an autochthonous breed from Minorca Island in the Balearic archipelago (NW Mediterranean Sea), is established in the official standard, with females being shorter and longer than males as well as having slenderer necks and a squarer croup. However, no study so far has explored the size and shape components of this dimorphism separately. The aim of this study was to analyse the morphology of this breed using geometric morphometric methods in order to find size and shape differences between sire lines. The analysis was based on landmarks digitized in lateral view from 38 registered adult Minorcan horses (20 males and 18 females) within an age range of 3–14 years (average 7 years) with different performance goals. The analyses did not reveal any significant differences between the “shape” and “size” of male and female animals, for the landmarks studied, so the sexes are functionally similar.

Averaging v. outlier removal. Decrypting variance among cryptic Lejeunea species (Lejeuneaceae: Jungermanniopsida) using geometric morphometrics

2013 ◽  
Vol 26 (1) ◽  
pp. 13 ◽  
Author(s):  
Matt A. M. Renner ◽  
Elizabeth A. Brown ◽  
Glenda M. Wardle
Keyword(s):  
Cryptic Species ◽  
Individual Variation ◽  
Species Difference ◽  
Molecular Data ◽  
Species Variation ◽  
Shape Variation ◽  
Outlier Removal ◽  
Geometric Morphometric ◽  
Size And Shape ◽  
Developmental Capacity

Molecular data have revealed many morphologically cryptic species. More surprising than lack of difference, however, is that morphological variation and complex patterns of overlapping features can mask cryptic species. We employ geometric morphometric methods (GMM) to explore patterns of variation within four liverwort species, three of which were previously attributed to Lejeunea tumida Mitt. Each species exhibited considerable variation within, and overlap among, species in size and shape, independent of degree of relatedness. Most variation was expressed within individuals, suggesting that the observed breadth of variation was within the developmental capacity of single genotypes. Size and shape variation within, and consequently overlap among, individuals resulted primarily from variance in growth of shoots. Inter-specific differences were swamped by intra- and inter-individual variation. We coupled GMM with multivariate methods for outlier removal, and simple averaging of individuals to explore whether intra-individual variation could be reconciled to maximise the inter-species difference, facilitating resolution of cryptic species despite extensive morphological continuity and overlap. Unfortunately, outlier removal did not achieve separation among species, because removing extremes failed to eliminate overlap resulting from within-species variation. Individual averaging was partially successful in extracting L. tumida as a discrete entity but did not segregate the remaining three species. Although the challenges for morphology-based identification of cryptic species are significant, GMM provide one of the best sets of methods for identifying and communicating any subtle morphological differences that may exist.

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