morphological divergence
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Zootaxa ◽  
2021 ◽  
Vol 5067 (2) ◽  
pp. 151-186
Author(s):  
CARLA M. PENZ

Based on comparative morphology of adults, a phylogeny is proposed for the butterfly tribe Amathusiini (Nymphalidae, Satyrinae). The dataset includes 92 characters scored for 45 species in 12 genera, representing the most comprehensive phylogenetic analysis for this group. Parsimony analyses produced a well-resolved strict consensus tree where genera were divided in three main groups: (clade 1) Stichophthalma; (clade 2) Aemona, Faunis, Melanocyma and Taenaris; (clade 3) Enispe, Discophora, Thaumantis, Thauria, Amathusia, Amathuxidia, and Zeuxidia. While genera in clades 1 and 2 were found to be morphologically homogeneous, clade 3 showed remarkable morphological divergence between and within genera. The monophyly of most genera was recovered with variable levels of support, but Melanocyma and Taenaris nested within Faunis. Therefore, here Melanocyma NEW SYN. is subsumed within Faunis, and Taenaris STAT. REV. is regarded as a subgenus of Faunis. Mimicry likely evolved a single time within the Faunis-Taenaris assemblage, as species of Taenaris formed a monophyletic group. Results are compared to early classifications and recent DNA-based analyses, and points of agreement and conflicts are discussed.  


2021 ◽  
Author(s):  
Maximilian Wagner ◽  
Sandra Bračun ◽  
Anna Duenser ◽  
Christian Sturmbauer ◽  
Wolfgang Gessl ◽  
...  

AbstractBackgroundElasmoid scales are one of the most common dermal appendages and can be found in almost all species of bony fish differing greatly in their shape. Whilst the genetic underpinnings behind elasmoid scale development have been investigated, not much is known about the mechanisms involved in the shaping of scales. To investigate the links between gene expression differences and morphological divergence, we inferred shape variation of scales from two different areas of the body (anterior and posterior) stemming from ten haplochromine cichlid species from different origins (Lake Tanganyika, Lake Malawi, Lake Victoria and riverine). Additionally, we investigated transcriptional differences of a set of genes known to be involved in scale development and morphogenesis in fish.ResultsWe found that scales from the anterior and posterior part of the body strongly differ in their overall shape, and a separate look on scales from each body part revealed similar trajectories of shape differences considering the lake origin of single investigated species. Above all, nine as well as 11 out of 16 target genes showed expression differences between the lakes for the anterior and posterior dataset, respectively. Whereas in posterior scales four genes (dlx5, eda, rankl and shh) revealed significant correlations between expression and morphological differentiation, in anterior scales only one gene (eda) showed such a correlation. Furthermore, eda displayed the most significant expression difference between species of Lake Tanganyika and species of the other two younger lakes. Finally, we found genetic differences in downstream regions of eda gene (e.g. in the eda-tnfsf13b inter-genic region) that are associated with observed expression differences. This is reminiscent of a genetic difference in the eda-tnfsf13b inter-genic region which leads to gain or loss of armour plates in stickleback.ConclusionThese findings provide evidence for cross-species transcriptional differences of an important morphogenetic factor, eda, which is involved in formation of ectodermal appendages. These expression differences appeared to be associated with morphological differences observed in the scales of haplochromine cichlids indicating potential role of eda mediated signal in divergent scale morphogenesis in fish.


2021 ◽  
Vol 22 (16) ◽  
pp. 8670
Author(s):  
Alexander Kostmann ◽  
Barbora Augstenová ◽  
Daniel Frynta ◽  
Lukáš Kratochvíl ◽  
Michail Rovatsos

The lizards of the species-rich clade Scincoidea including cordylids, gerrhosaurids, skinks, and xantusiids, show an almost cosmopolitan geographical distribution and a remarkable ecological and morphological divergence. However, previous studies revealed limited variability in cytogenetic traits. The sex determination mode was revealed only in a handful of gerrhosaurid, skink, and xantusiid species, which demonstrated either ZZ/ZW or XX/XY sex chromosomes. In this study, we explored the karyotypes of six species of skinks, two species of cordylids, and one gerrhosaurid. We applied conventional and molecular cytogenetic methods, including C-banding, fluorescence in situ hybridization with probes specific for telomeric motifs and rDNA loci, and comparative genomic hybridization. The diploid chromosome numbers are rather conserved among these species, but the chromosome morphology, the presence of interstitial telomeric sequences, and the topology of rDNA loci vary significantly. Notably, XX/XY sex chromosomes were identified only in Tiliqua scincoides, where, in contrast to the X chromosome, the Y chromosome lacks accumulations of rDNA loci. We confirm that within the lizards of the scincoidean clade, sex chromosomes remained in a generally poor stage of differentiation.


Mammalia ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Bader H. Alhajeri

Abstract Molecular phylogenies support the monophyly of Desmodilliscus braueri and Pachyuromys duprasi as a clade basally split from all other gerbillines. While this monophyly supports their placement in a single tribe (Desmodilliscini), no morphological synapomorphies exist among desmodilliscines. This study compares the scale-independent cranial shapes of these two species using geometric morphometrics to determine how they differ and/or converge. Tribal synapomorphies, should they exist, may appear as interspecifically invariable cranial regions. No such invariable cranial regions were detected. The two species significantly differed in cranial size and shape. A small part of shape variation was allometric, with a weak unique allometric effect. No sexual size nor shape dimorphism was found. The sister taxa greatly differed in almost all cranial features, with Pachyuromys (when compared to Desmodilliscus) having a larger-sized cranium, with a larger bulla and suprameatal triangle, a more posteriorly placed palatine foramina, and more anteriorly shifted (and reduced) rostral cranial structures, due to being crowded by the hypertrophied bulla. Cranial variation patterns are consistent with the literature. The extreme morphological divergence among these species is explained by the distant divergence time and ecological differences. Absence of cranial shape synapomorphies does not preclude synapomorphies in other craniodental morphological features (e.g., detailed morphology of the dentition and cranial foramina) or in other morphological structures, such as the postcranial skeleton.


Author(s):  
Ildon Rodrigues Nascimento ◽  
Cândida Pereira da Silva ◽  
Irais Dolores Pascual-Reyes ◽  
Aline Torquato Tavares ◽  
Edilson Nonato da Silva ◽  
...  

Objective: The objective was to quantify the morphological diversity of Calophyllum brasiliense Cambes from four municipalities of the State of Tocantins employing morphological characteristics, to strengthen information on conservation and future breeding of the species. Methodology: Seeds were collected from four municipalities in the State of Tocantins and one in the State of São Paulo. The following were evaluated: plant height, stem diameter, root length, number of leaves, leaf area, root dry mass, shoot dry mass, total dry mass, and Dickson´s quality index. The data were subjected to univariate analysis of variance, Tocher grouping method, and UPGMA, obtaining a dendrogram through the generalized Mahalanobis distance. Results: The results showed a statistical difference of 1 and 5% probability. Dueré stood out in stem diameter(5.52 mm), Sandolandia in height (34.84 cm) and root length (42.13 cm). Formoso stood out in the number of leaves (34 leaves). Lagoa da Confusão in leaf area (856.28 cm 2 ) and São Paulo in root dry mass (16.20 g), shoot dry mass (12.38 g), total dry mass (16.20 g), and Dickson´s quality index (1.57). Implications: Variations in morphological characteristics can be used as a tool for genetic studies of guanandi progeny accordingto their similarity and/or differences. Conclusions: The morphological divergence evidenced that among the five studied areas it is possible to direct the collection of seeds to subsidize conservation strategies and future breeding of the species.


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