Shape Traits Research Articles

Biochemical composition and shape-dimensional traits of rosehip genotypes

Abstract In the present study, the biochemical composition and shape and dimensional traits of 25 rosehip (Rosa canina) genotypes were investigated. The shape and dimensional traits were determined by image processing technique. Seed-propagated rosehip genotypes belonging to R. canina were collected from the natural flora of Mesudiye (Ordu) and Talas (Kayseri) districts. Antioxidant activity (39.510–72.673 mmol · kg−1), total flavonoids (287.80–1,686.20 mg quercetin equivalent (QE) · kg−1) and total phenolics (38,519.40–79,080.60 mg gallic acid equivalent · kg−1) of the genotypes exhibited large variations. Width (12.2 mm) and thickness (12.5 mm) of fruits averages were found to be close to each other. The genotypes exhibited fruit lengths between 12.0 mm and 29.5 mm. Average projected area at horizontal orientation (179.7 mm2) was greater than the projected area at vertical orientation (120.4 mm2). Sphericity average was calculated as 71.4%. According to principal component (PC) analysis, the most important dimensional traits discriminating genotypes from each other were identified as surface area, geometric mean diameter and volume. In terms of shape attributes, distinctive differences were observed in sphericity, circularity, elongation and surface closure rates (SCR) of the genotypes. According to elliptic Fourier analysis (EFA), genotypes look like a sphere. In terms of shape, there were long, spherical, flat bottomed, pointed bottomed and asymmetric-looking genotypes indicating how environment and genotype affect the fruit shape. The greatest shape variation was transverse contraction and expansion. According to the clustering analysis for shape attributes, rosehip genotypes were classified into six groups. Dendrogram, scatter plots of linear discriminant analysis and paired comparison test results put forth the shape differences of the genotype successfully.

Functional macrophyte trait variation as a response to the source of inorganic carbon acquisition.

BackgroundThis study aims to compare variation in a range of aquatic macrophyte species leaf traits into three carbon acquisition groups: HCO3−, free CO2 and atmospheric CO2.MethodsThe leaf functional traits were measured for 30 species from 30 softwater lakes. Macrophyte species were classified into (1) free CO2, (2) atmospheric CO2 and (3) bicarbonate HCO3− groups. In each lake we collected water samples and measured eight environmental variables: depth, Secchi depth, photosynthetically active radiation (PAR), pH of water, conductivity, calcium concentration, total nitrogen and total phosphorus. In this study we applied the RLQ analysis to investigate the relationships between species functional traits (Q) and their relationship with environmental variables (R) constrained by species abundance (L).ResultsThe results showed that: (1) Aquatic macrophytes exhibited high leaf trait variations as a response to different inorganic carbon acquisition; (2) Traits of leaves refer to the acquisition of carbon for photosynthesis and serve to maximise this process; (3) In the wide softwater habitat, macrophyte species exhibited an extreme range of leaf economic spectrum (leaf area, leaf dry weight and specific leaf area) and wide range of shape trait expressed as circularity; (4) Macrophyte leaf traits are the result of adaptation to carbon acquisition in ambient environment.

Predicted strong genetic gains from the application of genomic selection to improve growth related traits in barramundi (Lates calcarifer)

Barramundi (Lates calcarifer) is a tropical species of increasing aquaculture interest. In efforts to accumulate genetic gains through selection, the species is now subject to several pedigree-based breeding programs globally; however, these breeding programs would further benefit from the implementation of genomic selection methodologies. Here we make genomic predictions for polygenic growth and body shape traits and compare expected genetic gains from genomic selection across several breeding strategies to those expected from pedigree-based on-farm selective breeding programs.A commercial scale cohort of barramundi (24 half-sib families) was grow-out at two farm locations, a brackish-water pond-based system in Queensland, and a freshwater recirculating aquaculture system (RAS) in Victoria. A total of 2139 fish were genotyped using a custom 70 k Axiom™ myDesign™ SNP array (ThermoFisher Scientific™) and phenotyped at harvest for whole fish weight (WFW), standard fish length (SL), body depth (BD), Fulton's condition factor (K) and body shape index (BS). Fillet weight (FW) was also recorded on a subset of Victorian fish. Heritabilities based on genomic relationships were estimated across barramundi from both farm sites for WFW (0.33 ± 0.06 to 0.35 ± 0.04), SL (0.27 ± 0.05 to 0.35 ± 0.04), BD (0.29 ± 0.06 to 0.30 ± 0.04), and K (0.14 ± 0.04 to 0.21 ± 0.04), and for FW (0.35 ± 0.16) in the Victorian site only. Genotype-by-environment interactions were also detected for all traits (GBLUP rg between locations ranging from 0.41 for K to 0.61 for SL).To optomise the design of a breeding program using genomic information, three possible genomic selection strategies were explored: MULTIPLE, separate breeding programs at each farm site; GENERAL, a single breeding program using the general effects from an interaction model; and SINGLE, a single breeding program based on the performance of individuals within one main farm site. The accuracy of GBLUP breeding value prediction for the WFW, SL and BD traits was higher than PBLUP for all scenarios (10–33% and 15–49% improved prediction accuracy in the Victoria and Queensland environments, respectively). Estimates of genetic gain were also consistently higher when GBLUP was applied (19–31% for WFW in VIC) compared to PBLUP (14–23% for WFW in VIC).Under the SINGLE scenario, genetic gains for the target farm site were the same as for MULTIPLE, but only 48–66% of the MULTIPLE gains were predicted for the non-target farm site. In comparison, GENERAL, which operates at half the cost of MULTIPLE, achieved 72–97% of the expected gains of MULTIPLE across farm sites, suggesting that it would be the most appropriate scenario for genomic selection in the production environments evaluated.

Phenotypic Diversity of Almond-Leaved Pear (Pyrus spinosa Forssk.) along Eastern Adriatic Coast

Almond-leaved pear (Pyrus spinosa Forssk., Rosaceae) is a scientifically poorly researched and often overlooked Mediterranean species. It is an insect-pollinated and animal-dispersed spiny, deciduous shrub or a small tree, with high-quality wood and edible fruits. The aim of the study was to assess the phenotypic diversity of almond-leaved pear in the eastern Adriatic region. The examination of phenotypic diversity was based on a morphometric analysis of 17 populations using ten phenotypic traits of leaves. Varieties of multivariate statistical analyses were conducted to evaluate the within- and among-population diversity. In addition, the Mantel tests were used to test the correlations between geographic, environmental, and phenotypic differences among populations. High phenotypic variability was determined both among and within the studied populations. Leaf-size-related traits proved to be the most variable ones, in contrast to more uniform leaf shape traits. Furthermore, three groups of populations were detected using multivariate statistical analyses. The first group included trees from northern- and southernmost populations characterized by high annual precipitation. However, the trees from the second and third group were highly overlapped without a clear geographical pattern. In addition, we revealed that both environmental and geographical interactions proved to be responsible for the patterns of phenotypic variation between almond-leaved pear populations, indicating significant isolation by environment (IBE) and isolation by distance (IBD) patterns. Overall, our results provide useful information about phenotypic diversity of almond-leaved pear populations for further conservation, breeding, and afforestation programs.

Bin mapping-based QTL analyses using three genetic populations derived from indica-japonica crosses uncover multiple grain shape heterosis-related loci in rice.

Exploitation of heterosis between indica and japonica has important significance in scientific research and agriculture application. However, the molecular mechanism of grain shape heterosis in indica-japonica hybrid remains unknown in rice (Oryza sativa L.). To reveal the genetic mechanism of grain shape in indica--japonica hybrid, we constructed a high-generation recombinant inbred line (RIL) population and two testcross hybrid populations derived from the cross of RILs and two cytoplasmic male sterile material (YTA and Z7A) and then performed a bin mapping-based quantitative trait locus (QTL) mapping of multiple grain shape traits, such as grain length (GL), grain width (GW), and grain length-to-width ratio (GLWR). A total of sixteen QTLs and 30 heterosis-related QTLs of grain shape traits were detected. We found that GS3, GS5, and OsPPKL2 were also correlated with grain shape both in RILs and two testcross hybrid populations. Homologous gene analysis emphasized two candidate grain shape-associated genes (LOC_Os06g14260 and LOC_Os04g51950). Our findings uncover multiple grain shape heterosis-related loci and provides a new insight into heterosis mechanism of grain shape in rice.

A novel morphological index applied to genetic improvement of body shape in grass carp Ctenopharyngodon idella

Body shape is an economically important trait in grass carp (Ctenopharyngodon idella) that directly influences consumer acceptance and farmer profitability. It is essential to incorporate shape traits into the ongoing breeding program, as this would be expected to achieve rapid growth and maintain a slender shape for cultured populations. Thus, the aim of this study was to explore a suitable morphological index for genetic improvement of shape traits in grass carp. The viscerosomatic index (VSI) was introduced as a quantitative indicator of individual slenderness for the evaluation of various morphological ratios. Then, based on correlation and path analysis among body measurements (BMs) and weights of 290 recorded individuals, nine representative ratios that can reflect body slenderness from different angles were employed in this study, including Fulton's condition factor (K), Richter's condition factor (B), and other length ratios of different BMs (S1–S7). The results showed that each of these ratios exhibited a favorable relationship with VSI, confirming that more slender individuals always have a lower VSI. Of these ratios, S1 (body height-to-body length ratio, BH/BL), S2 (body height-to-caudal peduncle height ratio, BH/CPH), and S3, calculated as (BH-CPH)/BL, had the top three correlation coefficients with VSI (r = 0.501, 0.558, and 0.591, respectively). Furthermore, the S3 index reached the highest correlation (r = 0.732) in the sample group (n = 50) of mean body weight of 1560.8 g, suggesting that a quantitative comparison of individual slenderness would be more accurate within this fish size range. In addition, 636 pedigreed fish from 21 full-sib families were used for estimates of genetic parameters via an animal model. In comparison with the low heritability of K, the three ratios showed moderate to high heritability (h2 = 0.47 ± 0.14, 0.20 ± 0.08, and 0.31 ± 0.11, respectively), indicating significant potential for their genetic improvement. However, there were weak but undesired phenotypic and genetic correlations between body weight and the three ratios (0.13 < rp < 0.19; 0.23 < rg < 0.50), predicting that selection for rapid growth may slowly lead to the development of a rotund shape. In conclusion, the novel S3 index was suggested as the preferred candidate of shape traits for selective breeding in grass carp, especially because its expected relative genetic gain (4.07% at 10% selection intensity) was higher than those of the others (1.44%–3.99%).

Genetic and phenotypic analyses reveal major quantitative loci associated to fruit size and shape traits in a non-flat peach collection (P. persica L. Batsch)

Fruit size and shape are critical agronomical and pomological attributes and prime targets in peach breeding programs. Apart from the flat peach type, a Mendelian trait well-characterized at the genetic level, ample diversity of fruit size and shapes is present across peach germplasms. Nevertheless, knowledge of the underlying genomic loci remains limited. In this work, fruit size and shape were assessed in a collection of non-flat peach accessions and selections, under controlled fruit load conditions. The architecture of these traits was then dissected by combining association and linkage mapping, revealing a major locus on the proximal end of chromosome 6 (qSHL/Fs6.1) explaining a large proportion of phenotypic variability for longitudinal shape and also affecting fruit size. A second major locus for fruit longitudinal shape (qSHL5.1), probably also affecting fruit size, was found co-localizing at locus G, suggesting pleiotropic effects of peach/nectarine traits. An additional QTL for fruit longitudinal shape (qSHL6.2) was identified in the distal end of chromosome 6 in a cross with an ornamental double-flower peach and co-localized with the Di2 locus, controlling flower morphology. Besides assisting breeding activities, knowledge of loci controlling fruit size and shape paves the way for more in-depth studies aimed at the identification of underlying genetic variant(s).

Strong trait correlation and phylogenetic signal in North American ground beetle (Carabidae) morphology

AbstractFunctional traits mediate species' responses to, and roles within, their environment and are constrained by evolutionary history. While we have a strong understanding of trait evolution for macro‐taxa such as birds and mammals, our understanding of invertebrates is comparatively limited. Here, we address this gap in North American beetles with a sample of ground beetles (Carabidae), leveraging a large‐scale collection and digitization effort by the National Ecological Observatory Network (NEON). For 154 ground beetle species, we measured seven morphological traits, which we placed into a recently developed effect–response framework that characterizes traits by how they predict species' effects on their ecosystems or responses to environmental stressors. We then used cytochrome oxidase 1 sequences from the same specimens to generate a phylogeny and tested the evolutionary tempo and mode of the traits. We found strong phylogenetic signal in, and correlations among, ground beetle morphological traits. These results indicate that, for these species, beetle body shape trait evolution is constrained, and phylogenetic inertia is a stronger driver of beetle traits than (recent) environmental responses. Strong correlations among effect and response traits suggest that future environmental drivers are likely to affect both ecological composition and functioning in these beetles.

Multivariate genome-wide association study of leaf shape in a Populus deltoides and P. simonii F1 pedigree.

Leaf morphology exhibits tremendous diversity between and within species, and is likely related to adaptation to environmental factors. Most poplar species are of great economic and ecological values and their leaf morphology can be a good predictor for wood productivity and environment adaptation. It is important to understand the genetic mechanism behind variation in leaf shape. Although some initial efforts have been made to identify quantitative trait loci (QTLs) for poplar leaf traits, more effort needs to be expended to unravel the polygenic architecture of the complex traits of leaf shape. Here, we performed a genome-wide association analysis (GWAS) of poplar leaf shape traits in a randomized complete block design with clones from F1 hybrids of Populus deltoides and Populus simonii. A total of 35 SNPs were identified as significantly associated with the multiple traits of a moderate number of regular polar radii between the leaf centroid and its edge points, which could represent the leaf shape, based on a multivariate linear mixed model. In contrast, the univariate linear mixed model was applied as single leaf traits for GWAS, leading to genomic inflation; thus, no significant SNPs were detected for leaf length, measures of leaf width, leaf area, or the ratio of leaf length to leaf width under genomic control. Investigation of the candidate genes showed that most flanking regions of the significant leaf shape-associated SNPs harbored genes that were related to leaf growth and development and to the regulation of leaf morphology. The combined use of the traditional experimental design and the multivariate linear mixed model could greatly improve the power in GWAS because the multiple trait data from a large number of individuals with replicates of clones were incorporated into the statistical model. The results of this study will enhance the understanding of the genetic mechanism of leaf shape variation in Populus. In addition, a moderate number of regular leaf polar radii can largely represent the leaf shape and can be used for GWAS of such a complicated trait in Populus, instead of the higher-dimensional regular radius data that were previously considered to well represent leaf shape.

Plant functional traits shape growth rate for xerophytic shrubs.

Trade-offs exist for xerophytic shrubs between functional traits, involving in water loss and assimilate accumulation, can contribute to its survival and growth rate regulation in arid environments. However, growth analysis based on plant functional traits has been focused on the study of herbs and woody species. It is still unclear how the functional traits of xerophytic shrubs regulate their growth rate. In this study, we selectedeight xerophytic shrubs as samples to analyze the regulation process of the functional traits of shrubs on growth rate. Plants were cultivated for three years, and three harvests (every one year) were carried out. Factors explaining between-species differences in relative growth rate (RGR) varied, depending on whether different ages were considered. The results showed that RGR was positively correlated with net assimilation rate, but there was a significant negative correlation with leaf area ration (LAR), specific leaf area (SLA), and leaf biomass ratio in the age 1. However, in the age 2, RGR showed a significant positive correlation with the morphological traits (i.e., leaf area ration and specific leaf area), but not with physiological traits (i.e., net assimilation rate) and leaf biomass allocation. Our results suggested that the fluctuation of environmental factors affects the regulation path of the plant functional traits on RGR of xerophytic shrubs. However, the analysis of causality model showed that no matter in which age, net assimilation rate and leaf area ration principally drive the variation in RGR among xerophytic shrubs.

Sensitive periods during the development and expression of vertebrate sexual signals: A systematic review.

Many sexually selected traits exhibit phenotypic plasticity. Despite a growing appreciation for the ecological context in which sexual selection occurs, and for the role of plasticity in shaping traits associated with local adaptation and divergence, there is an important gap in knowledge about the onset and duration of plasticity in sexual trait expression. Integrating this temporal dimension of plasticity into models of sexual selection informs our understanding of the information conveyed by sexual traits and our predictions related to trait evolution, and is critical in this time of unprecedented and rapid environmental change. We conducted a systematic review of 869 studies to ask how trait modalities (e.g., visual and chemical) relate to the onset and duration of plasticity in vertebrate sexual signals. We show that this literature is dominated by studies of coloration in birds and fish, and most studies take place during the breeding season. Where possible, we integrate results across studies to link physiology of specific trait modalities with the life stage (e.g., juvenile, breeding, or nonbreeding) during which plasticity occurs in well‐studied traits. Limitations of our review included a lack of replication in our dataset, which precluded formal analysis. We argue that the timing of trait plasticity, in addition to environmental context, is critical for determining whether and how various communication signals are associated with ecological context, because plasticity may be ongoing or occur at only one point in an individual's lifetime, and determining a fixed trajectory of trait expression. We advocate for careful consideration of the onset and duration of plasticity when analyzing how environmental variation affects sexual trait expression and associated evolutionary outcomes.

Genome‐wide association mapping for kernel shape and its association with β‐glucan content in oats

AbstractKernel shape and β‐glucan content are important attributes for oat (Avena sativa L.) millers. The identification of genomic regions controlling these traits, as well as their effect on phenotype, will enable rapid gain from selection. The objectives of this study were (a) to identify the genomic regions associated with kernel shape in an oat panel adapted to subtropical environments and (b) to clarify the relationship between kernel shape and β‐glucan content in oat. An elite oat panel comprising 406 inbred lines was assessed in Londrina and Eldorado do Sul, Southern Brazil. Genome‐wide association analyses were performed for each environment separately and also in a multi‐environment analysis. Phenotypic and genetic correlation coefficients were estimated between kernel shape traits and β‐glucan content. Genomic regions influencing kernel length were identified on Mrg06, Mrg21, and Mrg24. Kernel width and kernel thickness were genetically correlated and shared a quantitative trait locus, located on Mrg13 of the oat consensus map. Phenotypic and genetic correlations were found between kernel shape traits and β‐glucan content, indicating a negative relationship between kernel width or kernel thickness and β‐glucan content. Oat breeding programs that aim to maintain minimum levels of β‐glucan for nutrition and minimum kernel widths for milling will need to screen for both traits; otherwise, indirect selection will lead to unfavorable results. However, the negative correlation was not too strong (–0.4), suggesting that improvement for both traits can be made simultaneously.

Multiple phenotypic traits as triggers of host attacks towards ant symbionts: body size, morphological gestalt, and chemical mimicry accuracy

BackgroundAnt colonies are plagued by a diversity of arthropod guests, which adopt various strategies to avoid or to withstand host attacks. Chemical mimicry of host recognition cues is, for example, a common integration strategy of ant guests. The morphological gestalt and body size of ant guests have long been argued to also affect host hostility, but quantitative studies testing these predictions are largely missing. We here evaluated three guest traits as triggers of host aggression—body size, morphological gestalt, and accuracy in chemical mimicry—in a community of six Eciton army ant species and 29 guest species. We quantified ant aggression towards 314 guests in behavioral assays and, for the same individuals, determined their body size and their accuracy in mimicking ant cuticular hydrocarbon (CHC) profiles. We classified guests into the following gestalts: protective, myrmecoid, staphylinid-like, phorid-like, and larval-shaped. We expected that (1) guests with lower CHC mimicry accuracy are more frequently attacked; (2) larger guests are more frequently attacked; (3) guests of different morphological gestalt receive differing host aggression levels.ResultsArmy ant species had distinct CHC profiles and accuracy of mimicking these profiles was variable among guests, with many species showing high mimicry accuracy. Unexpectedly, we did not find a clear relationship between chemical host similarity and host aggression, suggesting that other symbiont traits need to be considered. We detected a relationship between the guests’ body size and the received host aggression, in that diminutive forms were rarely attacked. Our data also indicated that morphological gestalt might be a valuable predictor of host aggression. While most ant-guest encounters remained peaceful, host behavior still differed towards guests in that ant aggression was primarily directed towards those guests possessing a protective or a staphylinid-like gestalt.ConclusionWe demonstrate that CHC mimicry accuracy does not necessarily predict host aggression towards ant symbionts. Exploitation mechanisms are diverse, and we conclude that, besides chemical mimicry, other factors such as the guests’ morphological gestalt and especially their body size might be important, yet underrated traits shaping the level of host hostility against social insect symbionts.

Jan Strelau: Two perspectives

We discuss the life and work of Jan Strelau from the perspectives of the Regulative Theory of Temperament and Five-Factor Theory. Both posit that traits are early-appearing and relatively stable over time, have a substantial biological basis, can be found in human and non-human species, and must be inferred from the behaviors that express them; they differ in the scope of temperament, the role of the environment in shaping traits, and the adaptive function of traits. The instruments associated with the two theories converge empirically: The temperament traits of Briskness and Endurance are related to Conscientiousness, Perseveration and Emotional reactivity to Neuroticism, Activity to Extraversion, and Sensory sensitivity to Openness. Five informant ratings of Strelau concurred in showing that he was low in Neuroticism and high in Extraversion, Openness, and Conscientiousness. A biographical sketch shows that despite potentially traumatic events in childhood and adolescence, Strelau lived a full and productive life. His life course is consistent with the view of both theories that adult personality traits are chiefly a reflection of biological influences.

Pervasive admixture and the spread of a large-lipped form in a cichlid fish radiation.

Adaptive radiations have proven important for understanding the mechanisms and processes underlying biological diversity. The convergence of form and function, as well as admixture and adaptive introgression, are common in adaptive radiations. However, distinguishing between these two scenarios remains a challenge for evolutionary research. The Midas cichlid species complex (Amphilophus spp.) is a prime example of adaptive radiation, with phenotypic diversification occurring at various stages of genetic differentiation. One species, A. labiatus, has large fleshy lips, is associated with rocky lake substrates, and occurs patchily within Lakes Nicaragua and Managua. By contrast, the similar, but thin-lipped, congener, A. citrinellus, is more common and widespread. We investigated the evolutionary history of the large-lipped form, specifically regarding whether the trait has evolved independently in both lakes from ancestral thin-lipped populations, or via dispersal and/or admixture events. We collected samples from distinct locations in both lakes, and assessed differences in morphology and ecology. Using RAD-seq, we genotyped thousands of SNPs to measure population structure and divergence, demographic history, and admixture. We found significant between-species differences in ecology and morphology, local intraspecific differences in body shape and trophic traits, but only limited intraspecific variation in lip shape. Despite clear ecological differences, our genomic approach uncovered pervasive admixture between the species and low genomic differentiation, with species within lakes being genetically more similar than species between lakes. Taken together, our results suggest a single origin of large-lips, followed by pervasive admixture and adaptive introgression, with morphology being driven by local ecological opportunities, despite ongoing gene-flow.

Genetic, morphometric, and molecular analyses of interspecies differences in head shape and hybrid developmental defects in the wasp genus Nasonia.

Males in the parasitoid wasp genus Nasonia have distinct, species-specific, head shapes. The availability of fertile hybrids among the species, along with obligate haploidy of males, facilitates analysis of complex gene interactions in development and evolution. Previous analyses showed that both the divergence in head shape between Nasonia vitripennis and Nasonia giraulti, and the head-specific developmental defects of F2 haploid hybrid males, are governed by multiple changes in networks of interacting genes. Here, we extend our understanding of the gene interactions that affect morphogenesis in male heads. Use of artificial diploid male hybrids shows that alleles mediating developmental defects are recessive, while there are diverse dominance relationships among other head shape traits. At the molecular level, the sex determination locus doublesex plays a major role in male head shape differences, but it is not the only important factor. Introgression of a giraulti region on chromsome 2 reveals a recessive locus that causes completely penetrant head clefting in both males and females in a vitripennis background. Finally, a third species (N. longicornis) was used to investigate the timing of genetic changes related to head morphology, revealing that most changes causing defects arose after the divergence of N. vitripennis from the other species, but prior to the divergence of N. giraulti and N. longicornis from each other. Our results demonstrate that developmental gene networks can be dissected using interspecies crosses in Nasonia, and set the stage for future fine-scale genetic dissection of both head shape and hybrid developmental defects.

Parallel Evolution of Allometric Trajectories of Trophic Morphology between Sympatric Morphs of Mesoamerican Astyanax (Characidae)

Parallel evolution of the body shape and trophic-related traits has been detected between sympatric pairs of lake-dwelling characin fishes in Mesoamerica. Here, we evaluated the variation in and the ontogenetic allometric trajectories of trophic morphology between sympatric Astyanax morphs (elongate and deep-body) in two geographic systems, Lake Catemaco (Mexico) and San Juan River basin (Nicaragua and Costa Rica). Using geometric morphometrics, we determined the shape variation and disparity in the premaxillary bone, and the patterns of allometric trajectories between morphs in each system. We found a higher differentiation and disparity in the premaxilla shape between morphs from San Juan River basin than between the Lake Catemaco ones. We found shared (parallel evolution) patterns of divergence between systems, which included allometric trajectories showing a positive correlation between the premaxilla shape and log centroid size, as well as trajectories being extended in the elongated-body morph (truncated in the deep-body morph). Regarding the unique patterns of divergence, we recovered parallel allometric trajectories between morphs from Lake Catemaco, while the San Juan River basin morphs showed divergent trajectories. Our results are congruent with the hypothesis that divergence in trophic morphology can be considered a triggering factor in the divergence in the genus Astyanax from Mesoamerica.

Retraction Note: EDAR, LYPLAL1, PRDM16, PAX3, DKK1, TNFSF12, CACNA2D3, and SUPT3H gene variants influence facial morphology in a Eurasian population.

In human society, the facial surface is visible and recognizable based on the facial shape variation which represents a set of highly polygenic and correlated complex traits. Understanding the genetic basis underlying facial shape traits has important implications in population genetics, developmental biology, and forensic science. A number of single nucleotide polymorphisms (SNPs) are associated with human facial shape variation, mostly in European populations. To bridge the gap between European and Asian populations in term of the genetic basis of facial shape variation, we examined the effect of these SNPs in a European–Asian admixed Eurasian population which included a total of 612 individuals. The coordinates of 17 facial landmarks were derived from high resolution 3dMD facial images, and 136 Euclidean distances between all pairs of landmarks were quantitatively derived. DNA samples were genotyped using the Illumina Infinium Global Screening Array and imputed using the 1000 Genomes reference panel. Genetic association between 125 previously reported facial shape-associated SNPs and 136 facial shape phenotypes was tested using linear regression. As a result, a total of eight SNPs from different loci demonstrated significant association with one or more facial shape traits after adjusting for multiple testing (significance threshold p < 1.28 × 10−3), together explaining up to 6.47% of sex-, age-, and BMI-adjusted facial phenotype variance. These included EDAR rs3827760, LYPLAL1 rs5781117, PRDM16 rs4648379, PAX3 rs7559271, DKK1 rs1194708, TNFSF12 rs80067372, CACNA2D3 rs56063440, and SUPT3H rs227833. Notably, the EDAR rs3827760 and LYPLAL1 rs5781117 SNPs displayed significant association with eight and seven facial phenotypes, respectively (2.39 × 10−5 < p < 1.28 × 10−3). The majority of these SNPs showed a distinct allele frequency between European and East Asian reference panels from the 1000 Genomes Project. These results showed the details of above eight genes influence facial shape variation in a Eurasian population.

Functional traits shape tree species distribution in the Himalayas

Abstract Plant functional traits determine plant performance and have therefore the potential to shape and predict species distributions along environmental gradients. This study analyses how traits affect tree species distribution along an elevational gradient in the Himalayas, Nepal. We addressed three questions: (a) what plant strategies can be distinguished among tree species? (b) how are plant traits and strategies associated with elevation? and (c) what plant traits are the best predictors of species positions along elevational gradient? We quantified for 31 tree species a set of 39 plant traits related to resource uptake, use and conservation. We analysed how traits cluster into separate functions using a cluster analysis, and how traits and clusters associate into distinct plant strategies using a principal component analysis. The cluster analysis showed five clusters of traits, reflecting (a) efficiency in vertical expansion, (b) efficiency in horizontal expansion, (c) efficiency in metabolism, (d) physical defence and (e) tree functional groups (conifers vs. broadleaf species). The first PCA axis reflects trade‐offs in traits and clusters linked to elevation: highland species had trait values that increase safety against freezing induced cavitation, high solar radiation and strong wind, and that increase resource conservation. In contrast, lowland species had trait values that increase efficiency of resource acquisition, metabolism and expansion. Additionally, a bivariate analysis showed that the first PCA axis is more strongly related to elevation than the individual traits, indicating that the combination of traits is more important than the individual traits. An all subsets regression analysis showed that a small set of traits best explain species distribution: highland species had smaller size (low basal area), safer hydraulics (low conduit diameter) and lower leaf and branch display efficiency (low leaf area per xylem area, specific branch length) that increase persistence under harsh conditions. Remarkably, leaf traits were poor predictors of species' elevational positions. Synthesis. Multiple trade‐offs in plant size, hydraulics and light competitiveness shape species distribution along the elevational gradient. Along this extreme environmental gradient, stem and branch traits that integrate multiple plant organs and functions are better predictors of species' elevational distributions than leaf traits.

Biting kinematics do not differ between ecologically divergent populations of Trinidadian guppies

AbstractPerformance, the ability to complete an ecologically relevant task, serves as a link between underlying morphology and the maximum functional capacity and fitness of an individual. Performance can vary within species due to environmental context and the trait of interest, but this is less understood compared with variation across species. Trinidadian guppy (Poecilia reticulata) populations are separated by waterfall barriers that result in repeated selection for predator avoidance in high predation environments and resource competition in low predation environments. An array of locally adapted traits results from these shifts, however, the role of these local adaptations in prey capture performance traits remains unclear. We examined biting kinematics in replicate populations of adult female guppies collected from natural high and low predation habitats. We expected that competition in low predation populations would drive performance differences compared with fish from high predation populations. Using high‐speed videos of fish feeding on an agar substrate, we did not find support for differences in jaw or approach kinematics between populations, suggesting a lack of local adaptation in our sample. To gain further insight, we examined four representative, whole‐body morphometric traits previously shown to be divergent in guppies. Again, differences were not discovered in our sample, which may indicate limitations in the use of shape traits. We suggest that female guppies are kinematic generalists and that selection on prey capture may act on traits other than performance, such as feeding behaviors (e.g., consumption rates, kinematic integration, and prey preference).