scholarly journals Convergent Evolution of Elongate Forms in Craniates and of Locomotion in Elongate Squamate Reptiles

2020 ◽  
Vol 60 (1) ◽  
pp. 190-201 ◽  
Author(s):  
Philip J Bergmann ◽  
Sara D W Mann ◽  
Gen Morinaga ◽  
Elyse S Freitas ◽  
Cameron D Siler
Keyword(s):  
Convergent Evolution ◽  
Evolutionary Dynamics ◽  
Tree Of Life ◽  
Locomotor Performance ◽  
Vertebral Number ◽  
Body Form ◽  
Squamate Reptiles ◽  
Remote Locations ◽  
Caudal Vertebrae ◽  
Vertebral Shape

Abstract Synopsis Elongate, snake- or eel-like, body forms have evolved convergently many times in most major lineages of vertebrates. Despite studies of various clades with elongate species, we still lack an understanding of their evolutionary dynamics and distribution on the vertebrate tree of life. We also do not know whether this convergence in body form coincides with convergence at other biological levels. Here, we present the first craniate-wide analysis of how many times elongate body forms have evolved, as well as rates of its evolution and reversion to a non-elongate form. We then focus on five convergently elongate squamate species and test if they converged in vertebral number and shape, as well as their locomotor performance and kinematics. We compared each elongate species to closely related quadrupedal species and determined whether the direction of vertebral or locomotor change matched in each case. The five lineages examined are obscure species from remote locations, providing a valuable glimpse into their biology. They are the skink lizards Brachymeles lukbani, Lerista praepedita, and Isopachys anguinoides, the basal squamate Dibamus novaeguineae, and the basal snake Malayotyphlops cf. ruficaudus. Our results support convergence among these species in the number of trunk and caudal vertebrae, but not vertebral shape. We also find that the elongate species are relatively slower than their limbed counterparts and move with lower frequency and higher amplitude body undulations, with the exception of Isopachys. This is among the first evidence of locomotor convergence across distantly related, elongate species.

Corrigendum to: Convergent evolution of sexually dimorphic glands in an amphi-Pacific harvestman family

2020 ◽  
Vol 34 (8) ◽  
pp. 906
Author(s):  
Guilherme Gainett ◽  
Rodrigo H. Willemart ◽  
Gonzalo Giribet ◽  
Prashant P. Sharma
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
New Species ◽  
Convergent Evolution ◽  
Evolutionary Dynamics ◽  
Sexually Dimorphic ◽  
Ecological Significance ◽  
Character Mapping ◽  
Recent Attention ◽  
Scanning Electron

Sexually dimorphic traits are widespread in animals, and include sex-specific weapons, ornamentation and, although less noticed, glands and associated structures. In arachnids, certain lineages of the order Opiliones exhibit diverse forms of dimorphism in the armature and length of appendages (common in Laniatores), as well as in the presence of sexually dimorphic glands (mostly investigated in Cyphophthalmi), positing harvestmen as promising models to study sexual dimorphism. Whereas the evolution and ecological significance of armature have been the focus of recent attention, sexually dimorphic glands remain understudied in groups other than Cyphophthalmi, despite being widespread in Opiliones. We therefore selected the amphi-Pacific family Zalmoxidae as an ideal taxon to investigate the evolutionary dynamics of this trait. We first describe four new species of Palaeotropical Zalmoxis, including a species with sexually dimorphic glands, and describe the morphology of zalmoxid species with sexually dimorphic glands using scanning electron microscopy. Using a previously assembled six-locus dataset supplemented with new terminals, and applying stochastic character mapping, we infer that sexually dimorphic glands evolved once in the Neotropics and at least four times in the Palaeotropic zalmoxids, revealing the evolutionary lability of this trait.

scholarly journals Snake W Sex Chromosome: The Shadow of Ancestral Amniote Super-Sex Chromosome

Cells ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 2386
Author(s):  
Worapong Singchat ◽  
Syed Farhan Ahmad ◽  
Nararat Laopichienpong ◽  
Aorarat Suntronpong ◽  
Thitipong Panthum ◽  
...  
Keyword(s):  
Sex Chromosomes ◽  
Evolutionary Dynamics ◽  
Sex Chromosome ◽  
Chromosomal Rearrangements ◽  
Chromosome Analysis ◽  
Chromosome Conformation ◽  
Principal Mechanism ◽  
Squamate Reptiles ◽  
Genomic Landscape ◽  
Heteromorphic Sex Chromosomes

Heteromorphic sex chromosomes, particularly the ZZ/ZW sex chromosome system of birds and some reptiles, undergo evolutionary dynamics distinct from those of autosomes. The W sex chromosome is a unique karyological member of this heteromorphic pair, which has been extensively studied in snakes to explore the origin, evolution, and genetic diversity of amniote sex chromosomes. The snake W sex chromosome offers a fascinating model system to elucidate ancestral trajectories that have resulted in genetic divergence of amniote sex chromosomes. Although the principal mechanism driving evolution of the amniote sex chromosome remains obscure, an emerging hypothesis, supported by studies of W sex chromosomes of squamate reptiles and snakes, suggests that sex chromosomes share varied genomic blocks across several amniote lineages. This implies the possible split of an ancestral super-sex chromosome via chromosomal rearrangements. We review the major findings pertaining to sex chromosomal profiles in amniotes and discuss the evolution of an ancestral super-sex chromosome by collating recent evidence sourced mainly from the snake W sex chromosome analysis. We highlight the role of repeat-mediated sex chromosome conformation and present a genomic landscape of snake Z and W chromosomes, which reveals the relative abundance of major repeats, and identifies the expansion of certain transposable elements. The latest revolution in chromosomics, i.e., complete telomere-to-telomere assembly, offers mechanistic insights into the evolutionary origin of sex chromosomes.

scholarly journals LINEs between Species: Evolutionary Dynamics of LINE-1 Retrotransposons across the Eukaryotic Tree of Life

2016 ◽  
Vol 8 (11) ◽  
pp. 3301-3322 ◽  
Author(s):  
Atma M. Ivancevic ◽  
R. Daniel Kortschak ◽  
Terry Bertozzi ◽  
David L. Adelson
Keyword(s):  
Evolutionary Dynamics ◽  
Tree Of Life

WHY DOES A TRAIT EVOLVE MULTIPLE TIMES WITHIN A CLADE? REPEATED EVOLUTION OF SNAKELIKE BODY FORM IN SQUAMATE REPTILES

Evolution ◽  
2006 ◽  
Vol 60 (1) ◽  
pp. 123 ◽  
Author(s):  
John J. Wiens ◽  
Matthew C. Brandley ◽  
Tod W. Reeder
Keyword(s):  
Body Form ◽  
Squamate Reptiles ◽  
Repeated Evolution

Vertebral number covaries with body form and elevation along the western slopes of the Ecuadorian Andes in the Neotropical fish genusRhoadsia(Teleostei: Characidae)

2019 ◽  
Vol 126 (4) ◽  
pp. 706-720 ◽  
Author(s):  
Windsor E Aguirre ◽  
Ashley Young ◽  
Ronald Navarrete-Amaya ◽  
Jonathan Valdiviezo-Rivera ◽  
Pedro Jiménez-Prado ◽  
...  
Keyword(s):  
Neotropical Fish ◽  
Vertebral Number ◽  
Body Form

scholarly journals LINES between species: Evolutionary dynamics of LINE-1 retrotransposons across the eukaryotic tree of life

2016 ◽  
Author(s):  
Atma M. Ivancevic ◽  
R. Daniel Kortschak ◽  
Terry Bertozzi ◽  
David L. Adelson
Keyword(s):  
Evolutionary Dynamics ◽  
Structural Characteristics ◽  
Mammalian Species ◽  
Tree Of Life ◽  
Open Reading Frames ◽  
Model Organisms ◽  
Individual Species ◽  
Evolutionary Patterns ◽  
Genomic Change ◽  
Domain Organisation

AbstractLINE-1 (L1) retrotransposons are dynamic elements. They have the potential to cause great genomic change due to their ability to ‘jump’ around the genome and amplify themselves, resulting in the duplication and rearrangement of regulatory DNA. Active L1, in particular, are often thought of as tightly constrained, homologous and ubiquitous elements with well-characterised domain organisation. For the past 30 years, model organisms have been used to define L1s as 6-8kb sequences containing a 5’-UTR, two open reading frames working harmoniously in cis, and a 3’-UTR with a polyA tail.In this study, we demonstrate the remarkable and overlooked diversity of L1s via a comprehensive phylogenetic analysis of over 500 species from widely divergent branches of the tree of life. The rapid and recent growth of L1 elements in mammalian species is juxtaposed against their decline in plant species and complete extinction in most reptiles and insects. In fact, some of these previously unexplored mammalian species (e.g. snub-nosed monkey, minke whale) exhibit L1 retrotranspositional ‘hyperactivity’ far surpassing that of human or mouse. In contrast, non-mammalian L1s have become so varied that the current classification system seems to inadequately capture their structural characteristics. Our findings illustrate how both long-term inherited evolutionary patterns and random bursts of activity in individual species can significantly alter genomes, highlighting the importance of L1 dynamics in eukaryotes.

scholarly journals Quantifying Parallel Evolution

2020 ◽  
Author(s):  
William R. Shoemaker ◽  
Jay T. Lennon
Keyword(s):  
Dimensionality Reduction ◽  
Evolutionary Dynamics ◽  
Parallel Evolution ◽  
Temporal Patterns ◽  
Tree Of Life ◽  
Microbial Populations ◽  
Gene Level ◽  
Evolutionary Trajectories

AbstractParallel evolution is consistently observed across the tree of life. However, the degree of parallelism between replicate populations in evolution experiments is rarely quantified at the gene level. Here we examine parallel evolution as the degree of covariance between replicate populations, providing a justification for the use of dimensionality reduction. We examine the extent that signals of gene-level covariance can be inferred in microbial evolve-and-resequence evolution experiments, finding that deviations from parallelism are difficult to quantify at a given point in time. However, this low statistical signal means that covariance between replicate populations is unlikely to interfere with the ability to detect divergent evolutionary trajectories for populations in different environments. Finally, we find evidence suggesting that temporal patterns of parallelism are comparatively easier to detect and that these patterns may reflect the evolutionary dynamics of microbial populations.

Convergent evolution of sexually dimorphic glands in an amphi-Pacific harvestman family

2020 ◽  
Author(s):  
Guilherme Gainett ◽  
Rodrigo H. Willemart ◽  
Gonzalo Giribet ◽  
Prashant P. Sharma
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
New Species ◽  
Convergent Evolution ◽  
Evolutionary Dynamics ◽  
Sexually Dimorphic ◽  
Ecological Significance ◽  
Character Mapping ◽  
Recent Attention ◽  
Scanning Electron

Sexually dimorphic traits are widespread in animals, and include sex-specific weapons, ornamentation and, although less noticed, glands and associated structures. In arachnids, certain lineages of the order Opiliones exhibit diverse forms of dimorphism in the armature and length of appendages (common in Laniatores), as well as in the presence of sexually dimorphic glands (mostly investigated in Cyphophthalmi), positing harvestmen as promising models to study sexual dimorphism. Whereas the evolution and ecological significance of armature have been the focus of recent attention, sexually dimorphic glands remain understudied in groups other than Cyphophthalmi, despite being widespread in Opiliones. We therefore selected the amphi-Pacific family Zalmoxidae as an ideal taxon to investigate the evolutionary dynamics of this trait. We first describe four new species of Palaeotropical Zalmoxis, including a species with sexually dimorphic glands, and describe the morphology of zalmoxid species with sexually dimorphic glands using scanning electron microscopy. Using a previously assembled six-locus dataset supplemented with new terminals, and applying stochastic character mapping, we infer that sexually dimorphic glands evolved once in the Neotropics and at least four times in the Palaeotropic zalmoxids, revealing the evolutionary lability of this trait.

scholarly journals Habitat determines convergent evolution of cephalic horns in vipers

2021 ◽  
Author(s):  
Theo Busschau ◽  
Stephane Boissinot
Keyword(s):  
Sexual Selection ◽  
Convergent Evolution ◽  
Evolutionary Significance ◽  
Squamate Reptiles ◽  
Selective Pressures ◽  
Selection For ◽  
Ambush Foraging ◽  
Shed Light ◽  
Forest Habitats ◽  
Phenotypic Convergence

Phenotypic convergence of traits in similar environments can provide insights into the evolutionary processes shaping trait evolution. Among squamate reptiles, horn-like cephalic appendages have evolved under various selective pressures, including selection for defence, crypsis or sexual selection. Yet, among snakes, particularly vipers, the functional and evolutionary significance of horns are unknown. We used a comparative phylogenetic approach with habitat and diet data on 263 viper taxa to shed light on the selective pressures underlying horn evolution in vipers. We detected significant correlations with habitat but not diet. The relative positions of horns are ecologically divergent in that supranasal horns are positively correlated with terrestrial forest habitats while supraocular horns are negatively correlated with terrestrial forest habitats and associated with arboreal or sparsely vegetated habitats. Multiple independent origins of supranasal or supraocular horns in similar habitats provide evidence of adaptive convergence. Comparisons with other snake lineages suggest that cephalic appendages may have evolved under selection for crypsis in ambush foraging snakes.

Sign in / Sign up

Export Citation Format

Share Document