scholarly journals Monogenean anchor morphometry: systematic value, phylogenetic signal, and evolution

2015 ◽  
Author(s):  
Tsung Fei Khang ◽  
Oi Yoon Michelle Soo ◽  
Wooi Boon Tan ◽  
Lee Hong Susan Lim
Keyword(s):  
Phylogenetic Signal ◽  
Principal Component ◽  
Morphological Integration ◽  
Root Tip ◽  
P Value ◽  
Maximum Parsimony Tree ◽  
28S Rrna ◽  
Shape Variation ◽  
Size Evolution ◽  
Shape And Size

Anchors are important attachment appendages that prevent the physical dislodging of a monogenean parasite from fish host gills. Common descent and evolutionary processes have left their mark on anchor morphometry, in the form of patterns of shape and size variation useful for systematic and evolutionary studies. We used a geometric morphometric approach to explore anchor shape variation in 13 Ligophorus (Monogenea:Ancyrocephalidae) species infecting two marine mugilid (Teleostei: Mugilidae) fish hosts (Moolgarda buchanani and Liza subviridis) in the waters off West Peninsular Malaysia. Molecular sequence data from three nuclear markers: 28S rRNA, 18S rRNA and ITS1, were used to infer a maximum likelihood phylogeny to enable visualization of shape evolution in phylomorphospace. For inferring patterns of size evolution in the phylogeny, we used a size measure based on the first principal component of all pairwise Euclidean distances between landmarks. Cluster heat map and principal component analysis showed that anchor shape variation had sufficient systematic information for delimiting 12 of the 13 species. Adams' multivariate K test indicated significant correlation between anchor shape and phylogeny (p-value = 0.0001). We also discovered that characters based on anchor shaft shape, the length between inner and outer root tips and the length between inner root tip and the dent point were more phylogenetically informative than inner and outer lengths, as indicated by a maximum parsimony tree that was better resolved and had major clades congruent with those of the molecular phylogenetic tree. Continuous character mapping of size onto the inferred molecular phylogeny and Rayleigh’s test for departure from directional uniformity in each species’s landmark relative to the ancestor indicated that species infecting M. buchanani generally evolved larger and more robust anchors, while those infecting L. subviridis generally evolved smaller and more delicate anchors. Nevertheless, phylogenetic regression of anchor shape against body size and anchor size showed significant correlation (p-value = 0.02) between anchor shape and size, suggesting morphometric constraints in anchor evolution. Finally, morphological integration analysis revealed tight integration between the root and point compartments within anchors, confirming that the anchor functions as a single, fully integrated module. The present work is supported by the development of integrative analytical tools in the form of a new R package – monogeneaGM. By lowering barriers to data integration and analysis , we aim to encourage the scientific community to collect and contribute morphometric and genetic data from other Ligophorus species, which are essential for developing Ligophorus as a model system for understanding association between patterns of anchor shape size evolution and biodiversity in the Monogenea.

scholarly journals Monogenean anchor morphometry: systematic value, phylogenetic signal, and evolution

2015 ◽  
Author(s):  
Tsung Fei Khang ◽  
Oi Yoon Michelle Soo ◽  
Wooi Boon Tan ◽  
Lee Hong Susan Lim
Keyword(s):  
Phylogenetic Signal ◽  
Principal Component ◽  
Morphological Integration ◽  
Root Tip ◽  
P Value ◽  
Maximum Parsimony Tree ◽  
28S Rrna ◽  
Shape Variation ◽  
Size Evolution ◽  
Shape And Size

Anchors are important attachment appendages that prevent the physical dislodging of a monogenean parasite from fish host gills. Common descent and evolutionary processes have left their mark on anchor morphometry, in the form of patterns of shape and size variation useful for systematic and evolutionary studies. We used a geometric morphometric approach to explore anchor shape variation in 13 Ligophorus (Monogenea:Ancyrocephalidae) species infecting two marine mugilid (Teleostei: Mugilidae) fish hosts (Moolgarda buchanani and Liza subviridis) in the waters off West Peninsular Malaysia. Molecular sequence data from three nuclear markers: 28S rRNA, 18S rRNA and ITS1, were used to infer a maximum likelihood phylogeny to enable visualization of shape evolution in phylomorphospace. For inferring patterns of size evolution in the phylogeny, we used a size measure based on the first principal component of all pairwise Euclidean distances between landmarks. Cluster heat map and principal component analysis showed that anchor shape variation had sufficient systematic information for delimiting 12 of the 13 species. Adams' multivariate K test indicated significant correlation between anchor shape and phylogeny (p-value = 0.0001). We also discovered that characters based on anchor shaft shape, the length between inner and outer root tips and the length between inner root tip and the dent point were more phylogenetically informative than inner and outer lengths, as indicated by a maximum parsimony tree that was better resolved and had major clades congruent with those of the molecular phylogenetic tree. Continuous character mapping of size onto the inferred molecular phylogeny and Rayleigh’s test for departure from directional uniformity in each species’s landmark relative to the ancestor indicated that species infecting M. buchanani generally evolved larger and more robust anchors, while those infecting L. subviridis generally evolved smaller and more delicate anchors. Nevertheless, phylogenetic regression of anchor shape against body size and anchor size showed significant correlation (p-value = 0.02) between anchor shape and size, suggesting morphometric constraints in anchor evolution. Finally, morphological integration analysis revealed tight integration between the root and point compartments within anchors, confirming that the anchor functions as a single, fully integrated module. The present work is supported by the development of integrative analytical tools in the form of a new R package – monogeneaGM. By lowering barriers to data integration and analysis , we aim to encourage the scientific community to collect and contribute morphometric and genetic data from other Ligophorus species, which are essential for developing Ligophorus as a model system for understanding association between patterns of anchor shape size evolution and biodiversity in the Monogenea.

scholarly journals Monogenean anchor morphometry: systematic value, phylogenetic signal, and evolution

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e1668 ◽  
Author(s):  
Tsung Fei Khang ◽  
Oi Yoon Michelle Soo ◽  
Wooi Boon Tan ◽  
Lee Hong Susan Lim
Keyword(s):  
Body Size ◽  
Phylogenetic Signal ◽  
R Package ◽  
Copulatory Organ ◽  
Morphological Integration ◽  
28S Rrna ◽  
Morphometric Data ◽  
Geometric Morphometric ◽  
Shape Data ◽  
Shape And Size

Background.Anchors are one of the important attachment appendages for monogenean parasites. Common descent and evolutionary processes have left their mark on anchor morphometry, in the form of patterns of shape and size variation useful for systematic and evolutionary studies. When combined with morphological and molecular data, analysis of anchor morphometry can potentially answer a wide range of biological questions.Materials and Methods.We used data from anchor morphometry, body size and morphology of 13Ligophorus(Monogenea: Ancyrocephalidae) species infecting two marine mugilid (Teleostei: Mugilidae) fish hosts:Moolgarda buchanani(Bleeker) andLiza subviridis(Valenciennes) from Malaysia. Anchor shape and size data (n= 530) were generated using methods of geometric morphometrics. We used 28S rRNA, 18S rRNA, and ITS1 sequence data to infer a maximum likelihood phylogeny. We discriminated species using principal component and cluster analysis of shape data. Adams’sKmultwas used to detect phylogenetic signal in anchor shape. Phylogeny-correlated size and shape changes were investigated using continuous character mapping and directional statistics, respectively. We assessed morphological constraints in anchor morphometry using phylogenetic regression of anchor shape against body size and anchor size. Anchor morphological integration was studied using partial least squares method. The association between copulatory organ morphology and anchor shape and size in phylomorphospace was used to test the Rohde-Hobbs hypothesis. We created monogeneaGM, a new R package that integrates analyses of monogenean anchor geometric morphometric data with morphological and phylogenetic data.Results.We discriminated 12 of the 13Ligophorusspecies using anchor shape data. Significant phylogenetic signal was detected in anchor shape. Thus, we discovered new morphological characters based on anchor shaft shape, the length between the inner root point and the outer root point, and the length between the inner root point and the dent point. The species onM. buchananievolved larger, more robust anchors; those onL. subviridisevolved smaller, more delicate anchors. Anchor shape and size were significantly correlated, suggesting constraints in anchor evolution. Tight integration between the root and the point compartments within anchors confirms the anchor as a single, fully integrated module. The correlation between male copulatory organ morphology and size with anchor shape was consistent with predictions from the Rohde-Hobbs hypothesis.Conclusions.Monogenean anchors are tightly integrated structures, and their shape variation correlates strongly with phylogeny, thus underscoring their value for systematic and evolutionary biology studies. Our MonogeneaGM R package provides tools for researchers to mine biological insights from geometric morphometric data of speciose monogenean genera.

scholarly journals Genetic Architecture of Mandible Shape in Mice: Effects of Quantitative Trait Loci Analyzed by Geometric Morphometrics

Genetics ◽  
2001 ◽  
Vol 157 (2) ◽  
pp. 785-802
Author(s):  
Christian Peter Klingenberg ◽  
Larry J Leamy ◽  
Eric J Routman ◽  
James M Cheverud
Keyword(s):  
Quantitative Trait Loci ◽  
Geometric Morphometrics ◽  
Quantitative Trait ◽  
Principal Component ◽  
Inbred Strains ◽  
Interval Mapping ◽  
Morphological Integration ◽  
Developmental Genetics ◽  
Shape Variation ◽  
Trait Loci

Abstract This study introduces a new multivariate approach for analyzing the effects of quantitative trait loci (QTL) on shape and demonstrates this method for the mouse mandible. We quantified size and shape with the methods of geometric morphometrics, based on Procrustes superimposition of five morphological landmarks recorded on each mandible. Interval mapping for F2 mice originating from an intercross of the LG/J and SM/J inbred strains revealed 12 QTL for size, 25 QTL for shape, and 5 QTL for left-right asymmetry. Multivariate ordination of QTL effects by principal component analysis identified two recurrent features of shape variation, which involved the positions of the coronoid and angular processes relative to each other and to the rest of the mandible. These patterns are reminiscent of the knockout phenotypes of a number of genes involved in mandible development, although only a few of these are possible candidates for QTL in our study. The variation of shape effects among the QTL showed no evidence of clustering into distinct groups, as would be expected from theories of morphological integration. Further, for most QTL, additive and dominance effects on shape were markedly different, implying overdominance for specific features of shape. We conclude that geometric morphometrics offers a promising new approach to address problems at the interface of evolutionary and developmental genetics.

scholarly journals Morphometric variation of Middle-American cichlids: Theraps– Paraneetroplus clade (Actinopterygii: Cichliformes: Cichlidae)

2021 ◽  
Vol 51 (4) ◽  
pp. 403-412
Author(s):  
Yanet Elizabeth Aguilar-Contreras ◽  
Alfonso A. González-Díaz ◽  
Omar Mejía ◽  
Rocío Rodiles-Hernández
Keyword(s):  
Body Shape ◽  
Phylogenetic Signal ◽  
Principal Component ◽  
The Body ◽  
Cranial Morphology ◽  
Group Method ◽  
Morphological Similarity ◽  
Shape Variation ◽  
Morphometric Variation ◽  
Mean Values

This study assesses the patterns of variation in body shape, and relations of morphological similarity among species of the Theraps–Paraneetroplus clade in order to determine whether body shape may be a trait in phylogenetic relations. A total of 208 specimens belonging to 10 species of the Theraps–Paraneetroplus clade were examined. The left side of each specimen was photographed; in each photograph, 27 fixed landmarks were placed to identify patterns in body shape variation. Images were processed by using geometric morphometrics, followed by a phylogenetic principal component analysis. The phylogenetic signal for body shape was then calculated. To determine the relations in morphological similarity, a dendrogram was created using the unweighted pair group method and arithmetic mean values, while a Procrustes ANOVA and post-hoc test were used to evaluate significant differences between species and habitats. We found three morphological groups that differed in body length and depth, head size, and the position of the mouth and eyes. The body shape analysis recovered the morphotypes of seven species, and statistical differences were demonstrated in eight species. Based on traits associated with cranial morphology, Wajpamheros nourissati (Allgayer, 1989) differed the most among the species examined. No phylogenetic signal was found for body shape; this trait shows independence from ancestral relatedness, indicating that there is little congruence between morphological and genetic interspecific patterns. As evidenced by the consistently convergent morphology of the species in the Theraps–Paraneetroplus clade, the diversification of the group is related to an ecological opportunity for habitat use and the exploitation of food resources. Although no phylogenetic signal was detected for body shape, there appears to be an order associated with cranial morphology-based phylogeny. However, it is important to evaluate the intraspecific morphologic plasticity produced by ecological segregation or partitioning of resources. Therefore, future morphological evolutionary studies should consider cranial structures related to the capture and processing of food.

scholarly journals Comparative Phylogenetics of Papilio Butterfly Wing Shape and Size Demonstrates Independent Hindwing and Forewing Evolution

2020 ◽  
Vol 69 (5) ◽  
pp. 813-819 ◽  
Author(s):  
H L Owens ◽  
D S Lewis ◽  
F L Condamine ◽  
A Y Kawahara ◽  
R P Guralnick
Keyword(s):  
Mate Recognition ◽  
Wing Shape ◽  
Batesian Mimicry ◽  
Museum Specimens ◽  
Shape Variation ◽  
Geometric Morphometric ◽  
Data Resource ◽  
Size Evolution ◽  
Comparative Phylogenetics ◽  
Shape And Size

Abstract The complex forces that shape butterfly wings have long been a subject of experimental and comparative research. Butterflies use their wings for flight, camouflage, mate recognition, warning, and mimicry. However, general patterns and correlations among wing shape and size evolution are still poorly understood. We collected geometric morphometric measurements from over 1400 digitized museum specimens of Papilio swallowtails and combined them with phylogenetic data to test two hypotheses: 1) forewing shape and size evolve independently of hindwing shape and size and 2) wing size evolves more quickly than wing shape. We also determined the major axes of wing shape variation and discovered that most shape variability occurs in hindwing tails and adjacent areas. We conclude that forewing shape and size are functionally and biomechanically constrained, whereas hindwings are more labile, perhaps in response to disruptive selective pressure for Batesian mimicry or against predation. The development of a significant, re-usable, digitized data resource will enable further investigation on tradeoffs between flight performance and ecological selective pressures, along with the degree to which intraspecific, local-scale selection may explain macroevolutionary patterns. [Batesian mimicry; Lepidoptera; geometric morphometrics; museum specimens.]

scholarly journals Evolutionary changes in the orbits and palatal openings of early tetrapods, with emphasis on temnospondyls

2018 ◽  
Vol 109 (1-2) ◽  
pp. 333-350
Author(s):  
Florian WITZMANN ◽  
Marcello RUTA
Keyword(s):  
Phylogenetic Signal ◽  
Principal Component ◽  
Linear Measurements ◽  
Functional Roles ◽  
Evolutionary Changes ◽  
Complex Models ◽  
Early Tetrapods ◽  
Tetrapod Evolution ◽  
Shape And Size

ABSTRACTOpen palates with large interpterygoid vacuities are a diagnostic characteristic of temnospondyl amphibians, the most species-rich group of early tetrapods. Aside from their functional roles, several other aspects of such vacuities, such as their variation and spatial relationships relative to the orbits, have received only scarce attention. The present work examines patterns of shape and size changes in the orbits and vacuities of temnospondyls using a time-calibrated phylogeny of 69 temnospondyl taxa and 13 additional early tetrapod ‘outgroups' (colosteids, an embolomere, ‘microsaurs' and nectrideans). Orbit and vacuity outlines are quantified in a comparative framework using standard eigenshape analyses. In addition, we employ a series of ratios of linear measurements of both orbits and vacuities, and subject them to a phylogenetic principal component analysis in order to evaluate their proportional changes relative to the skull and to one another. Finally, we examine rates of evolutionary change and their associated shifts for shape and size for both structures, and assess the strength and significance of the correlations between these two variables using phylogenetic generalised least squares analyses. Although orbits and vacuities have fairly simple outlines, they both reveal complex models of proportional change across the temnospondyl phylogeny. These changes exhibit strong phylogenetic signal, that is, trait covariance among taxa is predicted by tree topology. We discuss the hypothesis that, early in tetrapod evolution, the functional role of the vacuities was related to the accommodation of the anterior jaw muscles. Only later in evolution did such vacuities serve to accommodate the eye muscles only.

scholarly journals Variation of the Three-Dimensional Femoral J-Curve in the Native Knee

2021 ◽  
Vol 11 (7) ◽  
pp. 592
Author(s):  
Sonja A. G. A. Grothues ◽  
Klaus Radermacher
Keyword(s):  
Geometric Parameter ◽  
Knee Kinematics ◽  
Size Variation ◽  
Principal Component ◽  
Parameter Analysis ◽  
Patient Specific ◽  
3D Analysis ◽  
Relative Location ◽  
Shape Variation ◽  
J Curve

The native femoral J-Curve is known to be a relevant determinant of knee biomechanics. Similarly, after total knee arthroplasty, the J-Curve of the femoral implant component is reported to have a high impact on knee kinematics. The shape of the native femoral J-Curve has previously been analyzed in 2D, however, the knee motion is not planar. In this study, we investigated the J-Curve in 3D by principal component analysis (PCA) and the resulting mean shapes and modes by geometric parameter analysis. Surface models of 90 cadaveric femora were available, 56 male, 32 female and two without respective information. After the translation to a bone-specific coordinate system, relevant contours of the femoral condyles were derived using virtual rotating cutting planes. For each derived contour, an extremum search was performed. The extremum points were used to define the 3D J-Curve of each condyle. Afterwards a PCA and a geometric parameter analysis were performed on the medial and lateral 3D J-Curves. The normalized measures of the mean shapes and the aspects of shape variation of the male and female 3D J-Curves were found to be similar. When considering both female and male J-Curves in a combined analysis, the first mode of the PCA primarily consisted of changes in size, highlighting size differences between female and male femora. Apart from changes in size, variation regarding aspect ratio, arc lengths, orientation, circularity, as well as regarding relative location of the 3D J-Curves was found. The results of this study are in agreement with those of previous 2D analyses on shape and shape variation of the femoral J-Curves. The presented 3D analysis highlights new aspects of shape variability, e.g., regarding curvature and relative location in the transversal plane. Finally, the analysis presented may support the design of (patient-specific) femoral implant components for TKA.

scholarly journals Person - job fi t and the work commitment of IT Personnel

2016 ◽  
Vol 26 (2) ◽  
pp. 218 ◽  
Author(s):  
Therasa C. ◽  
C. Vijayabanu
Keyword(s):  
Regression Analysis ◽  
Principal Component ◽  
Attrition Rate ◽  
P Value ◽  
Work Commitment ◽  
Key Factors ◽  
Coeffi Cients ◽  
Work Autonomy ◽  
Major Factors ◽  
The Impact

Introduction: There have been given a much higher importance to employee commitment and retention since India is experiencing the highest attrition rate globally Economic Times, 2015. Hence, considering the factors of Person-job fi t to interpret the impact towards work commitment is very well essential, especially in the current scenario. Work Commitment is a vital element in any organization which has outstanding impact on productivity and functioning and hence it is very much vital to have a committed workforce which is necessary in this competitive environment and tight labour market. In the same way, there is considerable amount of evidence that if P-J fi t is high then it will have a direct impact on organization commitment also. Person-job fi t is the compatibility between person’s competency and abilities and the requirements of the job Zheng et al.2. If there exists a mismatch between person-job fi t then the consequences might result in poor work commitment, low job satisfaction and extremely lower involvement in the job. Objective: This study analyzed the key factors that contribute to Person- job compatibility among IT workers and also analyzed the relationship and impact of Person- job compatibility towards work commitment. Methods: Exploratory Factor Analysis (EFA) was used to fi lter the key factors initially, followed by a linear regression technique to determine the impact of Person- job compatibility factors in work commitment on a sample of 300 employees. EFA used Principal Component analysis for extraction and Promax for rotation. Finally regression analysis was carried out to predict the work commitment through statistically significant person-job compatibility variables. Results: The impact of person-job compatibility on work commitment was studied through regression analysis and it imply that for every unit increase in HR Policy, a 0.52 (unstandardised coeffi cients) increase in work commitment is predicted and it has been turned out as a most impacting variable to predict work commitment. The coeffi cients for Relationship (B =.330, sig =.000), HR Policies (B =.519, sig =.000), Pay and Benefi ts (B =.386, sig =.000) and Employee Growth (B =.290, sig =.001) were statistically significant, since its p-value is .000 which is smaller than .05. The coeffi cients for Work Autonomy (B =.154, sig = .081) was not statistically signifi cant, since its p-value is 0.081 which is greater than.05. Conclusion: The major factors responsible for creating work commitment among IT employees are Relationship, HR Policies and strategies, Pay and benefi ts, Work autonomy and Employee growth. The most contributing regressors which accounts for creating work commitment are HR policies, Pay and benefi ts, Employee growth and work autonomy.

scholarly journals Unravelling the hybrid vigor in domestic equids: the effect of hybridization on bone shape variation and covariation

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Pauline Hanot ◽  
Anthony Herrel ◽  
Claude Guintard ◽  
Raphaël Cornette
Keyword(s):  
First Generation ◽  
Shape Change ◽  
Morphological Integration ◽  
Hybrid Vigor ◽  
F1 Hybrids ◽  
Shape Variation ◽  
Locomotor System ◽  
Domestic Horses ◽  
Functional Mechanisms ◽  
Underlying Processes

Abstract Background Hybridization has been widely practiced in plant and animal breeding as a means to enhance the quality and fitness of the organisms. In domestic equids, this hybrid vigor takes the form of improved physical and physiological characteristics, notably for strength or endurance. Because the offspring of horse and donkey is generally sterile, this widely recognized vigor is expressed in the first generation (F1). However, in the absence of recombination between the two parental genomes, F1 hybrids can be expected to be phenotypically intermediate between their parents which could potentially restrict the possibilities of an increase in overall fitness. In this study, we examine the morphology of the main limb bones of domestic horses, donkeys and their hybrids to investigate the phenotypic impact of hybridization on the locomotor system. We explore bone shape variation and covariation to gain insights into the morphological and functional expressions of the hybrid vigor commonly described in domestic equids. Results Our data reveal the occurrence of transgressive effects on several bones in the F1 generation. The patterns of morphological integration further demonstrate that the developmental processes producing covariation are not disrupted by hybridization, contrary to functional ones. Conclusions These results suggest that an increase in overall fitness could be related to more flexibility in shape change in hybrids, except for the main forelimb long bones of which the morphology is strongly driven by muscle interactions. More broadly, this study illustrates the interest of investigating not only bone shape variation but also underlying processes, in order to contribute to better understanding how developmental and functional mechanisms are affected by hybridization.

scholarly journals Antlers Characterization for Identification of Deer Species (Family Cervidae) in Indonesia

2019 ◽  
Vol 4 (3) ◽  
pp. 97
Author(s):  
Donan Satria Yudha ◽  
M Zulfiqar Meizar Pratama ◽  
Rury Eprilurahman
Keyword(s):  
Principal Component Analysis ◽  
Principal Component ◽  
Morphological Characters ◽  
Main Beam ◽  
Size Measurement ◽  
Economic Values ◽  
Deer Species ◽  
Unique Character ◽  
Long Time ◽  
Shape And Size

There are five species of deer (family Cervidae) living in Indonesia today. Male deer possesses antlers, a unique character of male deer. Antlers have economic values for quite a long time. Antler’s growth is influenced by several factors, therefore each species of deer have its own unique antlers’ shape and size. Antler’s identification usually relies on size measurement and overall shape of complete antlers which still attach to the skull. It is difficult to identify shed, broken or individual antler. The purpose of the research is to understand antlers’ morphological characters on each species to become diagnostic characters. Specimens analysed were collections of LIPI and were analysed with Principal Component Analysis (PCA) using PAST3 software. The results showed each species of deer having their own unique antlers’ character, and so it can be used to determine the species of Indonesian deer. The important structures for identification are relief, pedicle, brow, bez, and main beam.

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