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Objective: Anopheles maculatus is recognized as an important malaria vector in Thailand and other countries within the Greater Mekong Subregion. This study employed both landmark and outline-based geometric morphometrics (GM) approaches to assess seasonal variation in the wing structure and wing contour of A. maculatus from malaria hotspots in western Thailand across three seasons: hot, wet, and dry. Materials and Methods: We analyzed seasonal variation in wing structure and contour using landmark-based and outline-based GM approaches, respectively, applied to the same image set of wing samples. Statistical differences in size and shape among seasonal populations were evaluated using a non-parametric analysis of variance (1,000 replicates), followed by a Bonferroni post hoc test. A p-value of less than 0.05 was used as the criterion for statistical significance in all analyses. Results: The size analyses revealed a significant difference in wing structure between the hot and dry seasons (p < 0.05), while no significant differences (p > 0.05) in wing contour across seasonal populations were detected. Significant differences (p < 0.05) in wing structure based on shape were detected between A. maculatus populations in the dry and hot seasons, as well as between populations in the dry and wet seasons. Wing contour analysis based on shape showed a significant difference (p < 0.05) only between the populations from the dry and wet seasons. Conclusion: These findings provide us with valuable information about the seasonal adaptation of A. maculatus, thus enhancing our understanding of vector population dynamics and potentially improving malaria surveillance strategies.

Recent studies have identified wing cells, a substructure of the wing, as carrying taxonomic signals across various mosquito genera. However, the presence of a taxonomic signal in the wing cells of the genus Lutzia (Diptera: Culicidae) has not yet been confirmed. Objective: This study aimed to evaluate the efficacy of the outline-based geometric morphometric (GM) approach in distinguishing Lutzia species found in Thailand, namely Lutzia chiangmaiensis, Lutzia fuscana, Lutzia halifaxii, and Lutzia vorax. Materials and Methods: The outline-based geometric morphometrics was employed to analyze four wing elements: the wing contour, the second submarginal cell, the first posterior cell, and the third posterior cell. Results: In the size analysis, Lt. vorax consistently exhibited significantly larger wing elements compared to the other species (p < 0.05). The factor maps based on discriminant analysis for the wing elements among the species indicated that most groups overlapped in morphospace. However, for the third posterior cell, the Lt. vorax group presented a more distinct shape. While shape analysis detected significant differences between almost all species pairs (p < 0.05), there was an exception between Lt. halifaxii and Lt. chiangmaiensis in the first posterior cell (p > 0.05). Additionally, shape analysis further indicated that the third posterior cell achieved the highest percentage of correct classifications, with an adjusted total assignment accuracy of 71%. Conclusion: This finding reveals a significant taxonomic signal in the third posterior cell, suggesting that the outline-based GM approach can effectively complement the landmark-based GM approach in distinguishing Lutzia species.

This study used 3D landmark-based geometric morphometrics under an object-symmetry framework to quantify pelvic asymmetry in domestic cats and dogs while explicitly accounting for measurement error through replicate digitizations. Procrustes ANOVA revealed significant components of both directional asymmetry (DA) and fluctuating asymmetry (FA) in the overall dataset, and DA was further visualized as a structured, non-random pattern across the landmark configuration. Measurement error remained smaller than the FA component, yielding high repeatability, indicating that the detected asymmetry patterns were not driven by landmarking imprecision. Group-wise summaries are presented as descriptive patterns of the sample (rather than direct between-group inference). In these descriptive summaries, cats tended to show a more coherent DA pattern, whereas dogs showed greater individual variation consistent with a relatively stronger FA component; males also tended to exhibit greater FA-related dispersion than females. In regression models of FA, age showed no association, body mass exhibited only a weak trend, and sex emerged as a significant predictor, while species showed no detectable effect when covariates were included. Collectively, these results support the hypothesis that pelvic shape contains both systematic (DA) and individual-specific (FA) asymmetry components, with sex-related differences in FA magnitude, but limited evidence for age- or weight-related effects within the sampled range. The study provides a repeatable framework and baseline reference for pelvic asymmetry in cats and dogs.

Invasive species can encounter environments different from their source populations, which may trigger rapid adaptive changes after introduction (niche shift hypothesis). To test this hypothesis, we investigated whether postintroduction evolution is correlated with contrasting environmental conditions between the European invasive and source ranges in the Asian tiger mosquito Aedes albopictus. The comparison of environmental niches occupied in European and source population ranges revealed more than 96% overlap between invasive and source niches, supporting niche conservatism. However, we found evidence for postintroduction genetic evolution by reanalyzing a published ddRADseq genomic dataset from 90 European invasive populations using genotype–environment association (GEA) methods and generalized dissimilarity modeling (GDM). Three loci, among which a putative heat-shock protein, exhibited significant allelic turnover along the gradient of winter precipitation that could be associated with ongoing range expansion. Wing morphometric traits weakly correlated with environmental gradients within Europe, but wing size differed between invasive and source populations located in different climatic areas. Niche similarities between source and invasive ranges might have facilitated the establishment of populations. Nonetheless, we found evidence for environmental-induced adaptive changes after introduction. The ability to rapidly evolve observed in invasive populations (genetic shift) together with a large proportion of unfilled potential suitable areas (80%) pave the way to further spread of Ae. albopictus in Europe.

Objectives: Aedeomyia catasticta is a mosquito species with relatively limited biological information. Therefore, this study aims to examine the geographical variation of wing shape in A. catasticta populations from different regions of Thailand using a landmark-based geometric morphometric approach. Materials and Methods: Samples of A. catasticta were collected from each of four regions of Thailand, each with distinct geographical and ecological characteristics: Eastern, Northeastern, Southern, and Western. Wing size was estimated by comparing centroid size (CS) values between populations. Differences in wing shape were assessed using the Mahalanobis distance, and statistical significance was tested using 10,000 permutations. Results: Statistical analyses of wing size indicated significant differences in wing CS among various pairs of populations across different regions, particularly between eastern and western, eastern and southern, and northeastern and western populations (p < 0.05). Statistical comparisons of wing shapes also demonstrated that wing shape varied significantly across all four regions (p < 0.05). Conclusions: The wing CS and shape of A. catasticta populations from different regions of Thailand may have been influenced by regional environmental factors, as indicated by geometric morphometric analyses. These findings improve understanding of regional morphological variation in this understudied mosquito species.

Abstract The genus Delminichthys consists of allopatric species restricted to ephemeral watercourses in the karst fields of the left-bank (D. ghetaldii) and the right-bank (D. adspersus and D. jadovensis) Neretva River basin as well as in the Una River drainage (D. krbavensis). The first aim addressed questions of interspecies variation and phylogenetic relationships among Delminichthys based on time-calibrated analysis of cyt b mtDNA (cytochrome b) and COI mtDNA (cytochrome c subunit I) mitochondrial DNA genes. Species-specific haplogroups supported two mtDNA genes as suitable barcoding markers, while we additionally proposed character-based and genetic distance threshold-based delimitation of species. We confirmed that the Pliocene and Pleistocene refugium for freshwater species was the Neretva basin, promoting the diversification of the genus Delminichthys. Our second aim was to test the population structure of D. ghetaldii (Southern Dalmatian minnow) by performing an integrative study using molecular mtDNA data, linear and geometric morphometric data. We consider that the spatial aspects of the population genealogical structure of D. ghetaldii mirror the Pleistocene paleodrainages. The differentiated COI mtDNA clusters corresponding to the populations from Fatničko Polje+Dabarsko Polje and Ljubomirsko Polje+Konavosko Polje represent geographically discrete genetic entities, which should be addressed through conservation management.

Levallois technology, a hallmark of Middle Palaeolithic stone tool manufacture, involves sophisticated core reduction strategies that have major implications for understanding human cognitive and technological evolution. However, traditional methods of analysing Levallois cores often fail to capture the nuanced variability in their morphology. This study introduces a novel application of three-dimensional geometric morphometrics (GM) to quantify the shape variability of Nubian Levallois cores from the Nile Valley and Dhofar regions. By employing this technique, we analysed core surfaces and preferential scar shapes, identifying distinct regional and technological patterns. Our results reveal significant inter-regional differences in core elongation and surface convexity, highlighting the importance of shape-oriented, rather than metric-based, analysis of prepared cores. This new GM approach offers a robust and replicable tool for investigating lithic variability and holds potential for broader applications in Palaeolithic research, enhancing our understanding of human technological adaptations.

Three-dimensional geometric morphometric methods have emerged as a pivotal tool in veterinary anatomy, taxonomy, clinical research, and studies of morphological diversity. This article summarizes the key stages, applications, clinical potential, and recommendations for data standardization in 3D morphometrics. Datasets are typically acquired using radiological modalities, including computed tomography (CT), magnetic resonance imaging (MRI), and 3D surface scanning, each offering specific advantages and constraints contingent on the research context. Standardized landmark sets are essential in 3D morphometric studies to ensure reproducibility and comparability of results across independent investigations. Consistent use of reference landmarks enables repeatable analyses, but the number of landmarks directly influences the required sample size and statistical power. Consequently, a minimal yet balanced landmark configuration is critical. This article proposes a standardized, minimal landmark set for the skulls of horses, cattle, and sheep to enhance inter-study reproducibility and comparability. Landmark selection prioritizes anatomically distinct points to avoid excessive landmarking, which may complicate analyses or compromise interpretability. Applications of 3D morphometric methods include orthopedic surgical planning, biomechanical modeling, and assessment of congenital anomalies, providing enhanced precision in diagnostics and research. In conclusion, 3D geometric morphometric methods represent a robust analytical framework in veterinary anatomy, morphology, and clinical research. Their significance is poised to grow through integration with automated landmarking, artificial intelligence-driven analyses, and international data-sharing networks, thereby advancing scientific inquiry in novel dimensions.

Only recently has the use of 3D-scanning technology enhanced our ability to consider shape using landmark approaches to geometric morphometrics (GM). Studies examining several types of anthropological datasets have provided mixed reviews of the utility of the third dimension in landmark GM shape analyses. In this paper we present the results of a study examining the methodological utility of three dimensions in landmark GM shape analysis of prehistoric stone points. We used GM to generate principal components (PCs) of shape variation from independent data sets of Clovis and Dalton points in different shape spaces using 2D and 3D versions of the same sample and examined variation in the distribution of shape variables on PCs generated for each data set. Results of uniform multivariate statistical tests performed on each dataset’s PCs were compared to observe whether 2D or 3D data is more effective at determining group membership. We then generated PCs of shape variation in the same shape space using dependent 2D and 3D datasets to observe whether 2D versions of the data cluster with corresponding 3D versions of each point in a PC biplot and multivariate cluster analysis. Results suggest that 2D GM analysis is as capable of discriminating between Clovis and Dalton points as analyses conducted with 3D data. However, those interested in manufacturing technology will benefit from information provided by 3D data sets, which can capture information such as original blank form and thinning strategies.

Background: The characterization of facial sexual dimorphic patterns in healthy populations serves as valuable normative data to tailor functionally effective surgical treatments and predict their aesthetic outcomes and to identify dysmorphic facial traits related to hormonal disorders and genetic syndromes. Although the analysis of facial sexual differences in juveniles of different ages has already been investigated, few studies have approached this topic with three-dimensional (3D) geometric morphometric (GMM) analysis, whose interpretation may add important clinical insight to the current understanding. This study aims to investigate the location and extent of facial sexual variations in juveniles through a spatially dense GMM analysis. Methods: We investigated 3D stereophotogrammetric facial scans of 304 healthy Italians aged 3 to 18 years old (149 males, 155 females) and categorized into four different age groups: early childhood (3–6 years), late childhood (7–12 years), puberty (13–15 years), and adolescence (16–18 years). Geometric morphometric analyses of facial shape (allometry, general Procrustes analysis, Principal Component Analysis, Procrustes distance, and Partial Least Square Regression) were conducted to detail sexually dimorphic traits in each age group. Results: The findings confirmed that males have larger faces than females of the same age, and significant differences in facial shape between the two sexes exist in all age groups. Juveniles start to express sexual dimorphism from 3 years, even though biological sex becomes a predictor of facial soft tissue morphology from the 7th year of life, with males displaying more protrusive medial facial features and females showing more outwardly placed cheeks and eyes. Conclusions: We provided a detailed characterization of facial change trajectories in the two sexes along four age classes, and the provided data can be valuable for several clinical disciplines dealing with the craniofacial region. Our results may serve as comparative data in the early diagnosis of craniofacial abnormalities and alterations, as a reference in the planning of personalized surgical and orthodontic treatments and their outcomes evaluation, as well as in several forensic applications such as the prediction of the face of missing juveniles.