Increasing ocean acidification is a concern due to its potential effects on the growth, development, and survival of early life stages of tuna in oceanic habitats and on the spatial extent of their ...suitable nursery habitat. To investigate the potential effects of increasing CO2 on otolith calcification of 9-day old pre-flexion stage yellowfin tuna (Thunnus albacares), an experiment was conducted at the Inter-American Tropical Tuna Commission's Achotines Laboratory in Panama during 2011. Fertilized eggs and larvae were exposed to mean pCO2 levels that ranged from present day (355 μatm) to two levels predicted to occur in some areas of the Pacific in the near future (2013 and 3321 μatm), and to an extreme value equivalent to long-term projections for 300 years in the future (9624 μatm). The results indicated significantly larger otoliths (in area and perimeter) with significant, and increasing, fluctuating asymmetry at acidification levels similar to those projected for the near future and long-term. Otoliths increased significantly in size despite a significant decrease in somatic length with increasing pCO2. A consistent correlation between otolith and somatic growth of yellowfin tuna larvae among treatments was evident (i.e., larger otoliths were still associated with larger larvae within a treatment). The observed changes in otolith morphology with increasing ocean acidification have the potential to indirectly affect larval survival through dysfunction of the mechanosensory organs, but this remains to be verified in yellowfin tuna larvae.
•Changes in otolith morphology and larval somatic growth with elevated pCO2 levels•Sagittae increased in size, asymmetry, abnormal shape at pH 7.6, 1712 μatm pCO2•Significant decrease in length of preflexion yellowfin larvae with elevated pCO2•Consistent correlation between otolith size and larva size at different pCO2 levels
The ossa coxae are the bones that connect the hindlimbs to the axial skeleton. The right and left os coxae join at the median plane to form the pelvis. In this study, variations in pelvis shape and ...the asymmetric structure of the pelvis were investigated across different classes of dogs. To achieve this, computed tomography images of the pelvis were obtained from 35 dogs, and 3D modelling of the pelvis was created. Subsequently, 45 landmarks were identified on these models. As a result of the Principal Component Analysis, the shape variation was observed in the pelvic canal and crista iliaca. Directional asymmetry between Principal Component 1 and Principal Component 2 accounted for 33.84% of the total variation, while fluctuating asymmetry contributed 23.66%. Canonical variate analysis revealed that canonical variate (CV) 1 explained 56.56% of the total variation between groups, with CV 2 explained 28.98%. Male dogs exhibited greater pelvic variation than females. Procrustes ANOVA indicated that the greatest proportion of shape variation corresponds to the effect of differences among individuals. While directional asymmetry was statistically significant, fluctuating asymmetry was not. Male dogs displayed more pronounced pelvic shape asymmetry, typically towards the right. Gundogs had a narrower pelvic canal and a wide crista iliaca, whereas terriers had a wider pelvic canal and smaller crista iliaca in shape. Geometric morphometry enables statistical analysis and the derivation of average shapes from samples, making it a vital tool in veterinary anatomy. This study provides insights into pelvic geometric morphometry across different classes of dogs.
Las plantas responden a cambios bióticos y abióticos acorde a su plasticidad fenotípica. Estas variaciones pueden expresarse en características relacionadas a la morfología foliar, crecimiento y ...defoliación. Este estudio evalúa la influencia de la edad de las plantas y de hojas sobre las características foliares, y su relación con la defoliación en tres especies forrajeras, Tithonia diversifolia, Morus alba y Moringa oleifera. M. oleifera mostró hojas con mayores valores de grosor, peso seco, asimetría y área; M. alba hojas más duras y con mayor área foliar especifica. M. oleifera el área foliar, peso seco, grosor y dureza incrementaron en plantas de 30 días. En tanto, que en M. alba las hojas intermedias tuvieron mayor área; y, las plantas de 90 días mayores valores de SLA, grosor y dureza. El área foliar y peso seco fueron mayores a los 60 y 30 días, respectivamente. En T. diversifolia las hojas intermedias presentaron mayor peso seco y grosor, las plantas de 30 días mayor área foliar y peso seco; y, las de 90 días, mayor grosor. Se encontraron relaciones negativas en hojas jóvenes con el grosor, dureza y peso seco. La defoliación mostró asociaciones positivas con el SLA y la dureza; y, negativas con el grosor, peso seco, asimetría y área. Subrayamos la importancia de realizar estudios que contribuyan al entendimiento de interrelaciones entre la estructura de la hoja, su función y sus relaciones con la expresión de los rasgos morfológicos de resistencia y tolerancia en especies tropicales de importancia económica y ecológica.
Hybridization emerges as a formidable evolutionary force, countering differentiation and fostering adaptive variation within populations. Hybridization crafts novel plant traits suited for unique ...ecological niches, thus significantly contributing to evolutionary dynamics. Here, we collected 300 individuals from a mixed forest, home to four native oak species - Quercus acutissima and Q. variabilis (Cerris group), and Q. fabri and Q. serrata var. brevipetiolata (Quercus group). To evaluate hybridization's role in adaptability, these individuals were classified into six genetic categories: two purebred types, first and second-generation hybrids, and two backcross generations. The analysis covered 20 traits, encompassing both leaf functionality and phenotype, to unravel the nuances and adaptive strategies of hybrids in comparison to purebreds. Our findings revealed substantial divergence in leaf functional traits between the two species groups, with hybrids exhibiting higher leaf chemical elements and stoichiometric ratios, particularly in carbon, nitrogen, and phosphorus. Additionally, leaf area-related indices displayed significant distinctions between hybrid and purebred phenotypes. Notably, hybrids in the Cerris group demonstrated intermediate leaf fluctuation asymmetry, whereas those in the Quercus group exhibited higher levels than their purebred counterparts. Additionally, we revealed that hybrids exhibited higher leaf phenotypic plasticity compared to purebreds. Hybrid individuals, through hybridization and introgression processes, evolved their genetic makeup to enhance nutrient absorption and phenotypic plasticity, thereby increasing their resilience to environmental stress. This study provides critical insights into the role of hybridization in creating phenotypic variability and enhancing plant adaptability, crucial features for breeding, management, and conservation efforts in the face of global climate change.
•Hybrid Oaks: Fix nitrogen, with unique leaf traits, showing vigor and adaptability.•Hybrid breeding with good traits contributes to forest management.•Introgression enhances hybrid growth and nitrogen-fixation, surpassing parental capabilities.
Fluctuating asymmetry of the hanging birch ( Betula pendula Roth), black poplar ( Populus nigra L . ), common ash ( Fraxinus excelsior L . ), common maple ( Acer platanoides L . ), common lilac ( ...Syringa vulgaris ) was evaluated as an integral measure based on five morphometric features of the plate. Samples of the leaf apparatus were taken at each point of technogenic load from the lower part of the crown of several close-growing trees of Betula pendula Roth, Populus nigra, Fraxinus, Acer platanoides and Syringa randomly select 30 intact leaves from each tree. In the future, calculations of the coefficient of fluctuating asymmetry were carried out in order to obtain an average value that determines the quality of the air environment corresponding to a certain score. An attempt was also made to find the correlation relationship of each bilateral feature with the average coefficient of fluctuating asymmetry. As a result, the correlation coefficient was equal to one, which corresponds to a high correlation. Considering this circumstance, it was decided to find a connection between the correlation dependence of the fluctuating asymmetry of the hanging birch with the fluctuating asymmetry of the leaf apparatus of poplar, maple, ash and lilac. The correlation coefficients were close to one, which made it possible to compile regression equations, with the help of which air quality assessment scales were compiled.
Approximately two decades after the first pioneering analyses, the study of shape asymmetry with the methods of geometric morphometrics has matured and is a burgeoning field. New technology for data ...collection and new methods and software for analysis are widely available and have led to numerous applications in plants and animals, including humans. This review summarizes the concepts and morphometric methods for studying asymmetry of shape and size. After a summary of mathematical and biological concepts of symmetry and asymmetry, a section follows that explains the methods of geometric morphometrics and how they can be used to analyze asymmetry of biological structures. Geometric morphometric analyses not only tell how much asymmetry there is, but also provide information about the patterns of covariation in the structure under study. Such patterns of covariation in fluctuating asymmetry can provide valuable insight about the developmental basis of morphological integration, and have become important tools for evolutionary developmental biology. The genetic basis of fluctuating asymmetry has been studied from empirical and theoretical viewpoints, but serious challenges remain in this area. There are many promising areas for further research that are only little explored at present.
Although symmetry, averageness, and sexual dimorphism are usually considered important to facial attractiveness, there are mixed findings regarding whether and how symmetry influences facial ...attractiveness. The present study introduced “facial normality” to explain the inconsistency of previous research. We hypothesized that symmetry only increased facial attractiveness when it improved facial normality. We manipulated symmetry and normality simultaneously on sixteen Chinese male faces and asked participants to rate the perceived symmetry, perceived normality, and facial attractiveness. The results demonstrated an interactive effect of symmetry and normality on facial attractiveness. The structural equation model results showed two paths from symmetry to facial attractiveness: (1) Symmetry reduced facial attractiveness by decreasing perceived normality; (2) Symmetry increased facial attractiveness by increasing the perceived symmetry and then improving perceived normality. In other words, perceived normality acted as a mediator between symmetry and facial attractiveness. The present study provides a solution to the different effects of symmetry on facial attractiveness in previous studies and suggests that future studies on symmetry and facial attractiveness should consider the mediating role of normality.
•Perceived normality positively predicts facial attractiveness.•Facial symmetry does not predict facial attractiveness independently.•Facial symmetry influences facial attractiveness via perceived facial normality.
The previous genetic characterization of the honeybee population of Mauritius Island (Indian Ocean) revealed an ongoing process of hybridization between the first established African subspecies Apis ...mellifera unicolor and recently imported European subspecies (A. m. ligustica, A. m. carnica and A. m. mellifera). This context offers the rare opportunity to explore the influence of hybridization between African and European honeybees on phenotypic traits out of the case largely studied of the Africanized honeybee (hybrid between A. m. scutellata from South Africa and European subspecies). We thus conducted geometric morphometric analyses on forewings of 283 workers genetically characterized at 14 microsatellite loci to evaluate (1) if the morphological variability coincides well with the neutral genetic variability, (2) if hybrids exhibited rather parental, intermediate or transgressive traits, and (3) to test if fluctuating asymmetry (FA) of size and shape, as a measure of developmental stability, was elevated in hybrids (due to genetic stress) and/or European bees (due to unsuitable environment) compared to African bees. A strong concordance was found between morphological variability and neutral genetic variability, especially for wing shape, based on partial least-square analyses (PLS). However, on average, the morphology of hybrids was more similar to the African bees, potentially reflecting the dynamics and direction of introgression. Significant FA for wing size as well as wing shape was detected, suggesting the overall presence of stress during the development of the studied individuals. In contrast, the asymmetry levels do not differ according to the ancestry (African, European or hybrid) of the individuals. Therefore, if ongoing hybridization contributed to increasing the genetic and phenotypic diversity of the populations and influences its adaptive potential, developmental stressors could not be identified and their evolutionary consequences remain uncertain.
The rice weevil, Sitophilus oryzae, is one of the most pernicious pests of stored grain. It is a primary pest and causes a reduction in weight, quality, seed viability and commercial value of various ...cereals. For this study, we reared S. oryzae on wheat grains under two different adult densities, low and high, with an aim to assess the influence of population density on fluctuating asymmetry of the adult's ventral body. Fluctuating asymmetry represents slight and random deviations from bilateral symmetry normally distributed around a 0 mean, and its level is usually higher under a disturbed developmental process. Accordingly, we expected that environmental stress caused by higher density would increase its level. Opposite to our hypothesis, the study showed that population density did not influence fluctuating asymmetry of S. oryzae adults. Both experimental populations exhibited a similar, non-significant level of fluctuating asymmetry.
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•Population density (PD) did not influence fluctuating asymmetry of S. oryzae adults.•PD did not induce stress or disturb developmental stability of S. oryzae adults.•Lack of FA may be due to female oviposition strategy and larval competition.
.— Morphometric studies often consider parts with internal left‐right symmetry, for instance, the vertebrate skull. This type of symmetry is called object symmetry and is distinguished from matching ...symmetry, in which two separate structures exist as mirror images of each other, one on each body side. We explain a method for partitioning the total shape variation of landmark configurations with object symmetry into components of symmetric variation among individuals and asymmetry. This method is based on the Procrustes superimposition of the original and a reflected copy of each landmark configuration and is compatible with the two‐factor ANOVA model customary in studies of fluctuating asymmetry. We show a fully multivariate framework for testing the effects in the two‐factor model with MANOVA statistics, which also applies to shapes with matching symmetry. We apply the new methods in a small case study of pharyngeal jaws of the Neotropical cichlid fish Amphilophus citrinellus. The analysis revealed that the symmetric component of variation in the pharyngeal jaws is dominated by the contrast between two alternative trophic morphs in this species and that there is subtle but statistically significant directional asymmetry. Finally, we provide some general recommendations for morphometric studies of symmetric shapes.
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