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1.
Zoology (Jena) ; 166: 126197, 2024 Sep.
Article in English | MEDLINE | ID: mdl-39232351

ABSTRACT

Living at high altitudes impose physiological and ecological challenges to which species may respond altering their body size, body proportions, and the shape of their body parts. Despite the importance of this topic for understanding the origin of species diversity, little attention has been invested in this phenomenon at the populational level. This paper study the relationship between altitude and body size, body proportions, and forewing shape venation of two populations of the parasitoid wasp Cotesia flavipes. Wasps were collected from Diatraea spp. larvae from sugarcane crops in two Colombian mountain ranges that cover between 600 m and 2143 m of altitude. Linear measurements of different body regions and geometric morphometrics of the forewing were subject to multivariate comparisons and allometric analyses to assess variation and to compare trends between ranges. Central (600 m to 1704 m) and Eastern Cordillera (877 m to 2143 m) populations showed different trends between body size and altitude. Allometric trends were not uniform within or between populations nor between structures. The allometric slopes of five body measurements from a single altitude differed from these from its own mountain range suggesting that body size trends along the cordilleras are a consequence of altitude and not of intrinsic body resource allocation processes. Wing shape between populations differed; however, these changes were poorly related to altitude. In agreement with recent studies in other groups, the observed allometric and wing shape differences between the two C. flavipes populations could be a plasticity response to altitude with interesting implications for posterior genetic differentiation.


Subject(s)
Altitude , Body Size , Wasps , Animals , Wasps/physiology , Wasps/anatomy & histology , Colombia , Wings, Animal/anatomy & histology
2.
Bone ; 189: 117263, 2024 Sep 21.
Article in English | MEDLINE | ID: mdl-39307297

ABSTRACT

Post-traumatic osteoarthritis (PTOA) in the temporomandibular joint (TMJ) is associated with remodeling of the subchondral bone. This remodeling changes both the external appearance of the condylar bone and the internal bony microstructure. The external geometry can be quantified using shape, a multivariate mathematical measurement that contains all of the structure's geometric information with location, scale, and rotation effects removed. There is an important gap in knowledge related to how TMJ PTOA affects the shape of the mandible and if the external shape covaries with the internal bony microstructure. To evaluate these gaps, TMJ PTOA was induced in male and female skeletally mature mice using a surgical destabilization procedure. After four weeks, tissues were collected and characterized using a high-resolution µCT scanner. Shape was calculated from surface reconstructions of the mandibular condyle, and the internal bony microstructure was characterized by the region of interest including the subchondral trabeculae. The covariance of shape with and without corrections for allometric scaling and internal bony microstructure was calculated using a Procrustes ANOVA. The data illustrate that PTOA significantly alters the shape of the condyle in a sex-independent manner. PTOA does alter some aspects of the internal bony microstructure in a sex-dependent manner. Allometric scaling was a significant factor in the variance of shape. Shape including the effects of allometric scaling significantly covaries with some internal bony microstructure variables in both sexes. Shape scaled to remove the effects of allometric scaling does not covary with internal bony microstructure in either sex. These findings indicate that PTOA progression is associated with changes in the size and shape of the condyle but variance in trabecular bone remodeling is only associated with size related shape change. Thus, the allostatic response of subchondral bone is multimodal, coordinating two independent biological processes controlling size and shape. Since subchondral bone participates in and guides the progression of PTOA, these findings have implications for identifying select and specific mechanisms contributing to the progression and pathophysiology of the PTOA in the TMJ.

3.
Conserv Physiol ; 12(1): coae064, 2024.
Article in English | MEDLINE | ID: mdl-39309467

ABSTRACT

Reproduction is a physiologically demanding process for sea turtles. Health indicators, including morphometric indices and blood analytes, provide insight into overall health, physiology and organ function for breeding sea turtles as a way to assess population-level effects. The Archie Carr National Wildlife Refuge (ACNWR) on Florida's central eastern coast is critical nesting habitat for loggerhead sea turtles (Caretta caretta), but health variables from this location have not been documented. Objectives of the study were to (1) assess morphometrics and blood analyte data (including haematology, plasma biochemistry, protein electrophoresis, ß-hydroxybutyrate, trace nutrients, vitamins and fatty acid profiles) from loggerheads nesting on or near the beaches of the ACNWR, (2) investigate correlations of body condition index (BCI) with blood analytes and (3) analyse temporal trends in morphometric and blood analyte data throughout the nesting season. Morphometric and/or blood analyte data are reported for 57 nesting loggerheads encountered between 2016 and 2019. Plasma copper and iron positively correlated with BCI. Mass tended to decline across nesting season, whereas BCI did not. Many blood analytes significantly increased or decreased across nesting season, reflecting the catabolic state and haemodynamic variations of nesting turtles. Twenty-three of 34 fatty acids declined across nesting season, which demonstrates the physiological demands of nesting turtles for vitellogenesis and reproductive activities, thus suggesting potential utility of fatty acids for the assessment of foraging status and phases of reproduction. The findings herein are relevant for future spatiotemporal and interspecies comparisons, investigating stressor effects and understanding the physiological demands in nesting sea turtles. This information provides comparative data for individual animals in rescue or managed care settings and for assessment of conservation strategies.

4.
Animals (Basel) ; 14(18)2024 Sep 13.
Article in English | MEDLINE | ID: mdl-39335254

ABSTRACT

The carapace morphology of tortoises is a crucial characteristic used for species identification, with features such as shell shape, roughness, and color patterns varying among species. Understanding this morphological diversity is valuable not only for taxonomic classification but also for more specialized clinical approaches. This study investigated the morphological differences in the shells of Leopard tortoises (Stigmochelys pardalis), African spurred tortoises (Centrochelys sulcata), and Greek tortoises (spur-thighed tortoises; Testudo graeca) raised in captivity. Using 3D scanners, the carapaces were modeled, and a 3D geometric morphometric method was employed to analyze shape variations and dimensional features, with landmarks applied automatically. Among the species studied, African spurred tortoises had the largest carapace size. Principal component analysis (PCA) identified PC1 and PC3 as critical factors in distinguishing between species based on morphological characteristics. Positive PC1 values, associated with a shorter carapace height, indicated a flatter or more compact shell shape. A higher PC3 value corresponded to a raised shape at the back of the shell, while a lower PC3 value indicated a raised shape at the front. Specifically, Leopard tortoises exhibited a higher carapace shape than the other species, while African spurred tortoises had shorter carapaces. An allometric effect was observed in the carapaces, where smaller specimens tended to be proportionately higher-domed, whereas larger shells displayed a lower height in shape. These findings highlight the significance of shape variations in tortoise shells, which emerge during adaptation and have important implications for taxonomy and clinical practice. Such differences should be carefully considered in veterinary care and species identification.

5.
Evol Lett ; 8(5): 669-679, 2024 Sep.
Article in English | MEDLINE | ID: mdl-39328290

ABSTRACT

A decline in diversity from the equator to the poles is a common feature of Earth's biodiversity. Here, we examine body shape diversity in marine fishes across latitudes and explore the role of time and evolutionary rate in explaining the diversity gradient. Marine fishes' occupation of upper latitude environments has increased substantially over the last 80 million years. Fishes in the highest latitudes exhibit twice the rate of body shape evolution and one and a third times the disparity compared to equatorial latitudes. The faster evolution of body shape may be a response to increased ecological opportunity in polar and subpolar oceans due to (1) the evolution of antifreeze proteins allowing certain lineages to invade regions of cold water, (2) environmental disturbances driven by cyclical warming and cooling in high latitudes, and (3) rapid transitions across depth gradients. Our results add to growing evidence that evolutionary rates are often faster at temperate, not tropical, latitudes.

6.
Sci Rep ; 14(1): 22207, 2024 Sep 27.
Article in English | MEDLINE | ID: mdl-39333563

ABSTRACT

The cultivation of grapevines has spanned millennia, leading to thousands of varieties through exchanges, mutations, and crosses between genotypes, as well probably as gene flow from wild populations. These varieties are typically categorized by regional origin and primary use, either for wine production or fruit consumption. France, within the Western European group, hosts many of the world's renowned wine grape varieties. However, the historical development of cultivated grapevines in France and in the world remains poorly understood. This study applies morphometry on 19,377 charred and waterlogged archaeological grape pips to investigate the evolutionary history of grapevine in France over the last 10,000 years. The study compares seed outlines and lengths, corrected for taphonomic distortions, with a reference collection of 80 wild and 466 modern domestic grapevine accessions. Findings reveal a shift from wild grapevine exploitation to the expansion of domestic varieties around 600-500 BCE, coinciding with Mediterranean cultural influences and the introduction of eastern grape types. The identification of the East-Table group, a group of varieties of eastern origin for fruit consumption, indicates that grapes were also grown for food, especially in Mediterranean regions and near urban areas, alongside wine production. Early French viticulture featured a notable presence of Western European wine-type grapevines. The abundance of pips with wild-like morphology suggests early cultivation involved plants at an initial domestication stage and gene flow between introduced and wild grapevines. As viticulture spread northward, wild and Eastern morphotypes declined, leading to the dominance of Western European wine types in inner France during the Middle Ages.


Subject(s)
Seeds , Vitis , Vitis/genetics , Vitis/anatomy & histology , France , Seeds/genetics , Seeds/anatomy & histology , Wine , Biological Evolution , Gene Flow
7.
J Hum Evol ; 195: 103581, 2024 Oct.
Article in English | MEDLINE | ID: mdl-39243703

ABSTRACT

The phylogenetic relationships of the small-bodied catarrhine Pliobates cataloniae (∼11.6 Ma, NE Iberian Peninsula) have been controversial since its original description. However, the recent report of additional dentognathic remains has supported its crouzeliid pliopithecoid status. Based on the available hypodigm, the molar enamel-dentine junction (EDJ) shape of P. cataloniae is compared with that of other pliopithecoids from the same basin as well as both extinct and extant hominoids to further evaluate its pliopithecoid affinities. We also quantitatively compare the EDJ shape among these taxa by means of landmark-based three-dimensional geometric morphometrics using principal component analysis (PCA), canonical variate analysis, and between-group PCA. Permutation tests are performed to test whether Pliobates variation exceeds that of extant hominoid genera. Results indicate that Pliobates is similar in molar EDJ shape to other pliopithecoids, particularly crouzeliids. The variation displayed by Pliobates upper molars is less marked at the EDJ level than at the outer enamel surface, probably owing to differential enamel wear and intraspecific differences in enamel thickness. Multivariate analyses of EDJ shape show that all pliopithecoids (including Pliobates) cluster together in the PCAs, canonical variate analyses, and between-group PCAs and occupy a different portion of the morphospaces from extinct and extant hominoids. Posterior and typicality probabilities strongly support the classification of Pliobates as a pliopithecoid, wheras permutation tests fail to reject the single-genus hypothesis for the P. cataloniae hypodigm. We conclude that P. cataloniae is a crouzeliid pliopithecoid, as recently supported by cladistic analyses of craniodental characters, and that previous cladistic results that supported a stem hominoid status are attributable to postcranial convergences with crown hominoids. Our results further highlight the potential of three-dimensional geometric morphometrics analyses of the EDJ shape for better informing fossil primate alpha-taxonomy by means of quantitatively testing hypotheses about tooth shape variation.


Subject(s)
Dental Enamel , Fossils , Molar , Animals , Molar/anatomy & histology , Dental Enamel/anatomy & histology , Fossils/anatomy & histology , Spain , Dentin/anatomy & histology , Catarrhini/anatomy & histology , Catarrhini/classification , Principal Component Analysis , Phylogeny , Hominidae/anatomy & histology , Hominidae/classification
8.
Am Nat ; 204(4): 345-360, 2024 Oct.
Article in English | MEDLINE | ID: mdl-39326057

ABSTRACT

AbstractInvasions of freshwater habitats by marine fishes provide exceptional cases of habitat-driven biological diversification. Freshwater habitats make up less than 1% of aquatic habitats but contain ∼50% of fish species. However, while the dominant group of freshwater fishes (Otophysi) is older than that of most marine fishes (Percomorphaceae), it is less morphologically diverse. Classically, scientists have invoked differences in the tempo and/or mode of evolution to explain such cases of unequal morphological diversification. We tested for evidence of these phenomena in the superfamily Cottoidea (sculpins), which contains substantial radiations of marine and freshwater fishes. We find that the morphology of freshwater sculpins evolves faster but under higher constraint than that of marine sculpins, causing widespread convergence in freshwater sculpins and more morphological disparity in marine sculpins. The endemic freshwater sculpins of Lake Baikal, Siberia, are exceptions that demonstrate elevated novelty akin to that of marine sculpins. Several tantalizing factors may explain these findings, such as differences in habitat stability and/or habitat connectivity between marine and freshwater systems.


Subject(s)
Biological Evolution , Ecosystem , Fresh Water , Perciformes , Animals , Perciformes/anatomy & histology , Perciformes/genetics , Phenotype , Siberia , Phylogeny
9.
Psychiatry Res ; 342: 116213, 2024 Sep 21.
Article in English | MEDLINE | ID: mdl-39326274

ABSTRACT

Development of the craniofacies occurs in embryological intimacy with development of the brain and both show normal left-right asymmetries. While facial dysmorphology occurs to excess in psychotic illness, facial asymmetry has yet to be investigated as a putative index of brain asymmetry. Ninety-three subjects (49 controls, 22 schizophrenia, 22 bipolar disorder) received 3D laser surface imaging of the face. On geometric morphometric analysis with (x, y, z) visualisations of statistical models for facial asymmetries, in controls the upper face and periorbital region, which share embryological intimacy with the forebrain, showed marked asymmetries. Their geometry included: along the x-axis, rightward asymmetry in its dorsal-medial aspects and leftward asymmetry in its ventral-lateral aspects; along the z-axis, anterior protrusion in its right ventral-lateral aspect. In both schizophrenia and bipolar disorder these normal facial asymmetries were diminished, with residual retention of asymmetries in bipolar disorder. This geometry of normal facial asymmetries shows commonalities with that of normal frontal lobe asymmetries. These findings indicate a trans-diagnostic process that involves loss of facial asymmetries in both schizophrenia and bipolar disorder. Embryologically, they implicate loss of face-brain asymmetries across gestational weeks 7-14 in processes that involve genes previously associated with risk for schizophrenia.

10.
Biol Lett ; 20(9): 20240103, 2024 Sep.
Article in English | MEDLINE | ID: mdl-39319669

ABSTRACT

The Eurasian otter is a wide-ranging semi-aquatic mammal that underwent a significant population decline in the last century, leading to local extinctions, reduction and fragmentation of populations. The individuals of populations exposed to both external and internal stress may present the inability to produce a specific developmental outcome, generating developmental 'noise' (developmental instability (DI)). Factors contributing to DI include inbreeding depression, population bottlenecks, habitat loss and exposure to pollution. We analysed fluctuating asymmetry (FA) as a proxy of DI in two European otter populations that experienced a major decline in the 1990s. Using three-dimensional geometric morphometrics methods on skull samples of otters from the UK and Sweden, we compared the degree of FA both between populations before, during and after the decline. We found a higher FA in the UK populations compared with Sweden. The level of asymmetry differed significantly over time only in the UK population, where it was higher during the decline phase. FA in the UK populations can be attributed to the specific impact of polychlorinated biphenyls pollution that caused a bottleneck. More generally, our study suggests that habitat loss, pollution and limited gene flow may contribute to DI in declining otter populations, highlighting the need for continued investigation to identify and quantify the specific stressors behind this trend in local populations.


Subject(s)
Otters , Animals , Otters/physiology , Sweden , United Kingdom , Population Dynamics , Male , Skull/anatomy & histology , Female , Ecosystem
11.
Parasitology ; : 1-16, 2024 May 22.
Article in English | MEDLINE | ID: mdl-39301619

ABSTRACT

Cylicospirura Vevers, 1922 is a genus of gastrointestinal spirurid nematodes parasitizing mainly felid but also canid, hyaenid and dasyurid hosts. Presently, 11 species are recognized worldwide, of which 4, Cylicospirura subaequalis, Cylicospirura felinea, Cylicospirura crocutae and Cylicospirura pardalis, have been recorded from African carnivores. In the present study, we describe Cylicospirura phiri n. sp. from hyaenas, namely Crocuta crocuta (type host) in Zimbabwe and Hyaena hyaena in Cameroon. The new species is the second species in the genus with bicuspid teeth. Furthermore, it can be distinguished from its congeners by a combination of characters, such as the absence of accessory teeth, the length and shape of the muscular oesophagus, position of the nerve ring, deirids and excretory pore in relation to the muscular oesophagus, the position of the vulva, spicule length and the shape of the female tail. Additionally, based on new material, detailed morphological descriptions are provided for C. crocutae and C. pardalis whose original descriptions were based on fragmented material. The material from Felis lybica, currently deposited as C. subaequalis, is described as C. felinea. First-time scanning electron micrographs are presented for the 4 species confirmed in African carnivores.

12.
Data Brief ; 56: 110799, 2024 Oct.
Article in English | MEDLINE | ID: mdl-39252769

ABSTRACT

Conformation traits are important in the selection and distinction between horse breeds, but tend to be evaluated subjectively within a breed and cannot be compared between them. The horse shape space model, using a combination of 253 landmarks and semi-landmarks, provides objective information on the shape of a horse photographed from the side that can be compared between breeds. In this dataset, we are providing the full set of 253 landmarks for 1241 horses from seven breeds, including an R code file to extract joint angle information and transform the raw data into csv files for further analysis, such as breed comparisons, heritability or genome-wide association studies (single- or multibreed). The repeatability of the joint angles are also reported.

13.
J Environ Manage ; 369: 122246, 2024 Oct.
Article in English | MEDLINE | ID: mdl-39241598

ABSTRACT

Seagrass meadows are an essential part of the Great Barrier Reef ecosystem, providing various benefits such as filtering nutrients and sediment, serving as a nursery for fish and shellfish, and capturing atmospheric carbon as blue carbon. Understanding the phenotypic plasticity of seagrasses and their ability to acclimate their morphology in response to environ-mental stressors is crucial. Investigating these morphological changes can provide valuable insights into ecosystem health and inform conservation strategies aimed at mitigating seagrass decline. Measuring seagrass growth by measuring morphological parameters such as the length and width of leaves, rhizomes, and roots is essential. The manual process of measuring morphological parameters of seagrass can be time-consuming, inaccurate and costly, so researchers are exploring machine-learning techniques to automate the process. To automate this process, researchers have developed a machine learning model that utilizes image processing and artificial intelligence to measure morphological parameters from digital imagery. The study uses a deep learning model called YOLO-v6 to classify three distinct seagrass object types and determine their dimensions. The results suggest that the proposed model is highly effective, with an average recall of 97.5%, an average precision of 83.7%, and an average f1 score of 90.1%. The model code has been made publicly available on GitHub (https://github.com/sajalhalder/AI-ASMM).


Subject(s)
Artificial Intelligence , Machine Learning , Ecosystem , Alismatales/anatomy & histology , Alismatales/growth & development
14.
J Nematol ; 56(1): 20240026, 2024 Mar.
Article in English | MEDLINE | ID: mdl-39221105

ABSTRACT

Turfgrass is a crop used extensively in athletic fields and golf courses in Maryland. A soil sample collected in July 2023 from an athletic field in Baltimore County, Maryland, part of a turfgrass nematode survey, contained Belonolaimus longicaudatus. In the southeastern United States, B. longicaudatus is an economically important pathogen of warm season turfgrass. The density was four individuals/100 cm3 of soil, and no visual symptoms were observed in the bermudagrass field. Morphological features and morphometrics of males and females were consistent with B. longicaudatus and placed the Maryland population in a subclade that was geographically represented by populations from north and west Florida, Texas, and South Carolina. Sequencing of the internal transcribed spacer region ITS1 and ITS2 and 28S large ribosomal subunit D2-23 expansion region confirmed the species' identity. Phylogenetic trees and parsimony network analysis placed the Maryland isolate in a large grouping of B. longicaudatus populations including those from Alabama, Delaware, Florida, Indiana, Mississippi, South Carolina, and Texas. To our knowledge, this is the first report of B. longicaudatus in Maryland.

15.
Acta Trop ; 259: 107380, 2024 Nov.
Article in English | MEDLINE | ID: mdl-39244138

ABSTRACT

Mosquito-borne diseases pose a significant public health challenge globally. Our study focused on the seasonal diversity of mosquito species in the connecting areas of the Tenasserim (also known as Tanaosri) range forests in Thailand. Additionally, we employed the geometric morphometric technique to assess variations in wing size and shape among five predominant mosquito species. Throughout the study period, we collected a total of 9,522 mosquitoes, encompassing 42 species across eight genera. In these connecting areas of forests, the Simpson index and Shannon species diversity index were recorded at 0.86 and 2.36, respectively, indicating a high level of mosquito diversity. Our analysis using the Analysis of Similarities (ANOSIM) test showed significant seasonal differences in mosquito communities, with an R-value of 0.30 (p < 0.05) in the lower connecting areas and 0.37 (p < 0.05) in the upper connecting areas. Additionally, canonical correspondence analyses showed that the abundance of each mosquito species is influenced by various climate factors. Phenotypic analyses of wing size and shape have deepened our understanding of local adaptation and the seasonal pressures impacting these vectors. Notably, most species exhibited larger wing sizes in the dry season compared to other seasons. Additionally, seasonal assessments of wing shape in five predominant mosquito species revealed significant differences across seasonal populations (p < 0.05). Ongoing monitoring of these populations is crucial to enhancing our understanding of the seasonal effects on mosquito abundance and physiological adaptations. These insights are essential for developing more effective strategies to manage mosquito-borne diseases.


Subject(s)
Climate , Culicidae , Forests , Mosquito Vectors , Seasons , Animals , Thailand , Mosquito Vectors/anatomy & histology , Mosquito Vectors/physiology , Mosquito Vectors/growth & development , Mosquito Vectors/classification , Culicidae/anatomy & histology , Culicidae/physiology , Culicidae/growth & development , Culicidae/classification , Wings, Animal/anatomy & histology , Biodiversity
16.
R Soc Open Sci ; 11(9): 240765, 2024 Sep.
Article in English | MEDLINE | ID: mdl-39263457

ABSTRACT

Comparative neuroanatomical studies have long debated the role of development in the evolution of novel and disparate brain morphologies. Historically, these studies have emphasized whether evolutionary shifts along conserved or distinct developmental allometric trends cause changes in brain morphologies. However, the degree to which interspecific differences between variably sized taxa originate through modifying developmental allometry remains largely untested. Taxa with disparate brain shapes and sizes thus allow for investigation into how developmental trends contribute to neuroanatomical diversification. Here, we examine a developmental series of large-bodied ratite birds (approx. 60-140 kg). We use three-dimensional geometric morphometrics on cephalic endocasts of common ostriches, emus and southern cassowaries and compare their developmental trajectories with those of the more modestly sized domestic chicken, previously shown to be in the same allometric grade as ratites. The results suggest that ratites and chickens exhibit disparate endocranial shapes not simply accounted for by their size differences. When shape and age are examined, chickens partly exhibit more accelerated and mature brain shapes than ratites of similar size and age. Taken together, our study indicates that disparate brain shapes between these differently sized taxa have emerged from the evolution of distinct developmental allometries, rather than simply following conserved scaling trends.

17.
Sci Rep ; 14(1): 20947, 2024 09 09.
Article in English | MEDLINE | ID: mdl-39251772

ABSTRACT

Seal lice, unique among insects, show remarkable adaptability to the extreme conditions of the deep sea. Evolving with their seal and sea lion hosts, they have managed to tolerate hypoxia, high salinity, low temperature, and elevated hydrostatic pressure. Given the diving capabilities of their mammalian hosts, which can reach depths of hundreds to thousands of meters, our study examines the morphological variation among closely related seal lice species infesting hosts with different maximum diving depths. In particular, our research reveals a significant morphological difference between lice associated with regular and deep-diving hosts, where lice from deep-diving hosts tend to be rounder. This could be an adaptation to withstand the high hydrostatic pressures found in the deep ocean. The rounded shape optimizes the louse's ability to withstand external pressure by redistributing it over a larger ventral/dorsal plane. This in turn minimizes the internal energy required to support body deformations, thereby increasing the louse's resilience in the deep sea environment.


Subject(s)
Diving , Animals , Diving/physiology , Host-Parasite Interactions , Lice Infestations/parasitology , Lice Infestations/veterinary , Seals, Earless/parasitology , Seals, Earless/physiology , Sea Lions/parasitology , Sea Lions/physiology
18.
Mol Ecol ; : e17524, 2024 Sep 16.
Article in English | MEDLINE | ID: mdl-39279721

ABSTRACT

Convergent evolution of similar phenotypes suggests some predictability in the evolutionary trajectories of organisms, due to strong and repeated selective pressures, and/or developmental constraints. In adaptive radiations, particularly in cichlid fish radiations, convergent phenotypes are commonly found within and across geographical settings. Cichlids show major repeated axes of morphological diversification. Recurrent changes in body patterns reveal adaption to alternative habitats, and modifications of the trophic apparatus respond to the exploitation of different food resources. Here we compare morphologically and genetically two Neotropical cichlid assemblages, the Mexican desert cichlid and the Nicaraguan Midas cichlid, with similar polymorphic body and trophic adaptations despite their independent evolution. We found a common morphological axis of differentiation in trophic structures in both cichlid radiations, but two different axes of differentiation in body shape, defining two alternative limnetic body patterns. Adaptation to limnetic habitats implied regulation of immune functions in the Midas cichlid, while morphogenesis and metabolic functions in the desert cichlid. Convergent phenotypic adaptions could be associated to divergent gene regulation.

19.
Sci Rep ; 14(1): 21822, 2024 09 18.
Article in English | MEDLINE | ID: mdl-39294199

ABSTRACT

The turtle shell is a remarkable structure that has intrigued not only evolutionary biologists but also engineering and material scientists because of its multi-scale complexity and various functions. Although protection is its most apparent role, the carapace and plastron are also related to many physiological functions and their shape influences hydrodynamics and self-righting ability. As such, analysing the functional morphology of the shell could help understanding the ecology of Triassic stem-turtles, which will contribute to the century-long debate on the evolutionary origins of turtles. Here, we used 3D imaging techniques to digitize the shells of two of the earliest stem-turtle taxa, Proganochelys and Proterochersis, and submitted their models to biomechanical and shape analyses. We analysed the strength performance under five predation scenarios and tested the function of two morphological traits found in stem-turtles, the epiplastral processes and an attached pelvic girdle. The latter, also present in the crown-lineage of side-necked turtles, has been suggested to increase load-bearing capacity of the shell or to improve swimming in pleurodires. Our results do not confirm the shell-strengthening hypothesis and, together with the results of our shape analyses, suggest that at least one of the first stem-turtles (Proterochersis) was an aquatic animal.


Subject(s)
Animal Shells , Biological Evolution , Turtles , Turtles/physiology , Turtles/anatomy & histology , Animals , Biomechanical Phenomena , Animal Shells/anatomy & histology , Animal Shells/physiology , Fossils
20.
Br J Psychol ; 2024 Sep 30.
Article in English | MEDLINE | ID: mdl-39347699

ABSTRACT

Human migration is an increasingly common phenomenon and migrants are at risk of disadvantageous treatment. We reasoned that migrants may receive differential treatment by locals based on the closeness of their facial features to the host average. Residents of Türkiye, the country with the largest number of refugees currently, served as participants. Because many of these refugees are of Arabic origin, we created target facial stimuli varying along the axis connecting Turkish and Arabic morphological prototypes (excluding skin colour) computed using geometric morphometrics and available databases. Participants made judgements of two universal dimensions of social perception-warmth and competence-on these faces. We predicted that participants judging faces manipulated towards the Turkish average would provide higher warmth and competence ratings compared to judging the same faces manipulated towards the Arabic average. Bayesian statistical tools were employed to estimate parameter values in multilevel models with intercorrelated varying effects. The findings did not support the prediction and revealed raters (as well as target faces) to be an important source of variation in social judgements. In the absence of simple cues (e.g. skin colour, group labels), the effect of facial morphology on social judgements may be much more complex than previously assumed.

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