Tissue-specific geometry and chemistry of modern and fossilized melanosomes reveal internal anatomy of extinct vertebrates

Recent discoveries of nonintegumentary melanosomes in extant and fossil amphibians offer potential insights into the physiological functions of melanin not directly related to color production, but the phylogenetic distribution and evolutionary history of these internal melanosomes has not been characterized systematically. Here, we present a holistic method to discriminate among melanized tissues by analyzing the anatomical distribution, morphology, and chemistry of melanosomes in various tissues in a phylogenetically broad sample of extant and fossil vertebrates. Our results show that internal melanosomes in all extant vertebrates analyzed have tissue-specific geometries and elemental signatures. Similar distinct populations of preserved melanosomes in phylogenetically diverse vertebrate fossils often map onto specific anatomical features. This approach also reveals the presence of various melanosome-rich internal tissues in fossils, providing a mechanism for the interpretation of the internal anatomy of ancient vertebrates. Collectively, these data indicate that vertebrate melanins share fundamental physiological roles in homeostasis via the scavenging and sequestering of metals and suggest that intimate links between melanin and metal metabolism in vertebrates have deep evolutionary origins.

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Wood anatomy of the Mascarene Dombeyoideae: Systematic and ecological implications

IAWA Journal ◽

10.1163/22941932-90000073 ◽

2011 ◽

Vol 32 (4) ◽

pp. 493-519 ◽

Cited By ~ 7

Author(s):

Anaïs Boura ◽

Timothée Le Péchon ◽

Romain Thomas

Keyword(s):

Evolutionary History ◽

Wood Anatomy ◽

Sister Group ◽

Biological Data ◽

Sister Group Relationship ◽

Anatomical Features ◽

Ecological Implications ◽

History Of ◽

Mascarene Islands ◽

Almost All

The Dombeyoideae (Malvaceae) are one of the most diversified groups of plants in the Mascarene Islands. Species of Dombeya Cav., Ruizia Cav. and Trochetia DC. are distributed in almost all parts of the archipelago and show a wide diversity in their growth forms. This study provides the first wood anatomical descriptions of 17 out of the 22 Mascarene species of Dombeyoideae. Their wood anatomy is similar to that of previously described species: wide vessels, presence of both apotracheal and paratracheal parenchyma, and storied structure. In addition, we also found a second wood anatomical pattern with narrower vessels, high vessel frequency and thick-walled fibres. The two aforementioned wood patterns are considered in a phylogenetic context and used to trace the evolutionary history of several wood anatomical features. For example, the pseudoscalariform pit arrangement supports a sister group relationship between Trochetia granulata Cordem. and T. blackburniana Bojer ex Baker and may be a new synapomorphy of the genus Trochetia. Finally, wood variability is evaluated in relation to geographic, climatic and biological data. Despite the juvenile nature of some of the specimens studied, we discuss how the habit, but also factors related to humidity, influence the variability observed in the Mascarene Dombeyoideae wood structure.

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Evolution of a chordate-specific mechanism for myoblast fusion

10.1101/2021.07.24.453587 ◽

2021 ◽

Author(s):

Haifeng Zhang ◽

Renjie Shang ◽

Kwantae Kim ◽

Wei Zheng ◽

Christopher J. Johnson ◽

...

Keyword(s):

Evolutionary History ◽

De Novo ◽

Myoblast Fusion ◽

Last Common Ancestor ◽

Functional Tests ◽

Evolutionary Origins ◽

New Genes ◽

History Of ◽

Early Vertebrates ◽

And Function

The size of an animal is determined by the size of its musculoskeletal system. Myoblast fusion is an innovative mechanism that allows for multinucleated muscle fibers to compound the size and strength of individual mononucleated cells. However, the evolutionary history of the control mechanism underlying this important process is currently unknown. The phylum Chordata hosts closely related groups that span distinct myoblast fusion states: no fusion in cephalochordates, restricted fusion and multinucleation in tunicates, and extensive, obligatory fusion in vertebrates. To elucidate how these differences may have evolved, we studied the evolutionary origins and function of membrane-coalescing agents Myomaker and Myomixer in various groups of chordates. Here we report that Myomaker likely arose through gene duplication in the last common ancestor of tunicates and vertebrates, while Myomixer appears to have evolved de novo in early vertebrates. Functional tests revealed an unexpectedly complex evolutionary history of myoblast fusion in chordates. A pre-vertebrate phase of muscle multinucleation driven by Myomaker was followed by the later emergence of Myomixer that enables the highly efficient fusion system of vertebrates. Thus, our findings reveal the evolutionary origins of chordate-specific fusogens and illustrate how new genes can shape the emergence of novel morphogenetic traits and mechanisms.

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Fossils with Feathers and Philosophy of Science

Systematic Biology ◽

10.1093/sysbio/syz010 ◽

2019 ◽

Vol 68 (5) ◽

pp. 840-851 ◽

Cited By ~ 1

Author(s):

Joyce C Havstad ◽

N Adam Smith

Keyword(s):

Philosophy Of Science ◽

Evolutionary History ◽

Scientific Practice ◽

Scientific Evidence ◽

Thomas Kuhn ◽

Karl Popper ◽

Scientific Debate ◽

Evolutionary Origins ◽

Research Programmes ◽

History Of

AbstractThe last half century of paleornithological research has transformed the way that biologists perceive the evolutionary history of birds. This transformation has been driven, since 1969, by a series of exciting fossil discoveries combined with intense scientific debate over how best to interpret these discoveries. Ideally, as evidence accrues and results accumulate, interpretive scientific agreement forms. But this has not entirely happened in the debate over avian origins: the accumulation of scientific evidence and analyses has had some effect, but not a conclusive one, in terms of resolving the question of avian origins. Although the majority of biologists have come to accept that birds are dinosaurs, there is lingering and, in some quarters, strident opposition to this view. In order to both understand the ongoing disagreement about avian origins and generate a prediction about the future of the debate, here we use a revised model of scientific practice to assess the current and historical state of play surrounding the topic of bird evolutionary origins. Many scientists are familiar with the metascientific scholars Sir Karl Popper and Thomas Kuhn, and these are the primary figures that have been appealed to so far, in prior attempts to assess the dispute. But we demonstrate that a variation of Imre Lakatos’s model of progressive versus degenerative research programmes provides a novel and productive assessment of the debate. We establish that a refurbished Lakatosian account both explains the intractability of the dispute and predicts a likely outcome for the debate about avian origins. In short, here, we offer a metascientific tool for rationally assessing competing theories—one that allows researchers involved in seemingly intractable scientific disputes to advance their debates.

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The differential pattern of tissue-specific expression of ruminant pancreatic type ribonucleases may help to understand the evolutionary history of their genes

Gene ◽

10.1016/s0378-1119(98)00586-1 ◽

1999 ◽

Vol 227 (2) ◽

pp. 205-212 ◽

Cited By ~ 8

Author(s):

Maria Paola Sasso ◽

Maria Lombardi ◽

Elena Confalone ◽

Antonella Carsana ◽

Marta Palmieri ◽

...

Keyword(s):

Evolutionary History ◽

Specific Expression ◽

Tissue Specific ◽

Tissue Specific Expression ◽

History Of ◽

Differential Pattern

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Comparative anatomy and phylogenetic contribution of intracranial osseous canals and cavities in armadillos and glyptodonts (Xenarthra, Cingulata)

10.1101/2021.04.21.440734 ◽

2021 ◽

Author(s):

Kévin Le Verger ◽

Laureano R. González Ruiz ◽

Guillaume Billet

Keyword(s):

3D Reconstruction ◽

Evolutionary History ◽

Comparative Anatomy ◽

Anatomical Variation ◽

Phylogenetic Study ◽

Internal Anatomy ◽

Emissary Vein ◽

X Ray ◽

History Of ◽

Selected Traits

ABSTRACTThe evolutionary history of the Cingulata, as for many groups, remains a highly debated topic to this day, particularly for one of their most emblematic representatives: the glyptodonts. There is no consensus among morphological and molecular phylogenies relative to their position within Cingulata. As demonstrated by recent works, the study of the internal anatomy constitutes a promising path for enriching morphological matrices for the phylogenetic study of armadillos. However, internal cranial anatomy remains under-studied in the Cingulata. Here we explored and compared the anatomy of intracranial osseous canals and cavities in a diverse sample of extant and extinct cingulates, including the earliest well-preserved glyptodont crania. The virtual 3D reconstruction (using X-ray microtomography) of selected canals, i.e., the nasolacrimal canal, the palatine canal, the sphenopalatine canal, the canal for the frontal diploic vein, the transverse canal, the orbitotemporal canal, the canal for the capsuloparietal emissary vein and the posttemporal canal, and alveolar cavities related to cranial vascularization, innervation or tooth insertion allowed us to compare the locations, trajectories and shape of these structures and to discuss their potential interest for cingulate systematics. We tentatively reconstructed evolutionary scenarios for eight selected traits on these structures, in which glyptodonts often showed a greater resemblance to pampatheres, to the genus Proeutatus and/or to chlamyphorines. This latter pattern was partly congruent with recent molecular hypotheses, but more research is needed on these resemblances and on the potential effects of development and allometry on the observed variations. Overall, these comparisons have enabled us to highlight new anatomical variation that may be of great interest to further explore the evolutionary history of cingulates and the origins of glyptodonts on a morphological basis.

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Genomic regression of claw keratin, taste receptor and light-associated genes inform biology and evolutionary origins of snakes

10.1101/127654 ◽

2017 ◽

Author(s):

Christopher A. Emerling

Keyword(s):

Evolutionary History ◽

Light Adaptation ◽

Gene Loss ◽

Taste Receptor ◽

Taste Buds ◽

Molecular Dating ◽

Evolutionary Origins ◽

Associated Functions ◽

History Of ◽

Dim Light

AbstractRegressive evolution of anatomical traits corresponds with the regression of genomic loci underlying such characters. As such, studying patterns of gene loss can be instrumental in addressing questions of gene function, resolving conflicting results from anatomical studies, and understanding the evolutionary history of clades. The origin of snakes coincided with the regression of a number of anatomical traits, including limbs, taste buds and the visual system. By studying the genomes of snakes, I was able to test three hypotheses associated with the regression of these features. The first concerns two keratins that are putatively specific to claws. Both genes that encode these keratins were pseudogenized/deleted in snake genomes, providing additional evidence of claw- specificity. The second hypothesis is whether snakes lack taste buds, an issue complicated by unequivocal, conflicting results in the literature. I found evidence that different snakes have lost one or more taste receptors, but all snakes examined retained at least some capacity for taste. The final hypothesis I addressed is that the earliest snakes were adapted to a dim light niche. I found evidence of deleted and pseudogenized genes with light- associated functions in snakes, demonstrating a pattern of gene loss similar to other historically nocturnal clades. Together these data also provide some bearing on the ecological origins of snakes, including molecular dating estimates that suggest dim light adaptation preceded the loss of limbs.

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Phylogeography of the ‘cosmopolitan’ orb-weaver Argiope trifasciata (Araneae: Araneidae)

Biological Journal of the Linnean Society ◽

10.1093/biolinnean/blaa078 ◽

2020 ◽

Vol 131 (1) ◽

pp. 61-75

Author(s):

Christoph Abel ◽

Jutta M Schneider ◽

Matjaž Kuntner ◽

Danilo Harms

Keyword(s):

Species Delimitation ◽

Evolutionary History ◽

New World ◽

Phylogenetic Analyses ◽

Single Species ◽

Spider Species ◽

Evolutionary Origins ◽

History Of ◽

Argiope Trifasciata ◽

Species Taxonomy

Abstract Few spider species show truly cosmopolitan distributions. Among them is the banded garden spider Argiope trifasciata, which is reported from six continents across major climatic gradients and geographical boundaries. In orb-weaver spiders, such global distributions might be a result of lively dispersal via ballooning. However, wide distributions might also be artefactual, owing to our limited understanding of species taxonomy. To test the hypothesis that A. trifasciata might be a complex of cryptic species with more limited geographical ranges, we investigated the biogeographical structure and evolutionary history of A. trifasciata through a combination of time-calibrated phylogenetic analyses (57 terminals and three genes), ancestral range reconstruction and species delimitation methods. Our results strongly suggest that A. trifasciata as currently defined is not a single species. Its populations fall into five reciprocally monophyletic clades that are genetically distinct and have evolutionary origins in the Plio-Pleistocene. These clades are confined to East Asia, temperate Australia, Hawaii, the New World and the Old World (Africa and most of the Palaearctic). Our results provide the basis for future investigation of morphological and/or ecological disparity between the populations that are likely to represent species, in addition to examinations of the attributes and dispersal modes of these species.

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Molecular and Functional Evolution of the Spermatophyte Sesquiterpene Synthases

International Journal of Molecular Sciences ◽

10.3390/ijms22126348 ◽

2021 ◽

Vol 22 (12) ◽

pp. 6348

Author(s):

Dongmei Liang ◽

Weiguo Li ◽

Xiaoguang Yan ◽

Qinggele Caiyin ◽

Guangrong Zhao ◽

...

Keyword(s):

Evolutionary History ◽

Chain Structure ◽

Signal Molecules ◽

Evolutionary Patterns ◽

Specific Product ◽

Evolutionary Origins ◽

Germacrene D ◽

History Of ◽

First Time ◽

Detailed Function

Sesquiterpenes are important defense and signal molecules for plants to adapt to the environment, cope with stress, and communicate with the outside world, and their evolutionary history is closely related to physiological functions. In this study, the information of plant sesquiterpene synthases (STSs) with identified functions were collected and sorted to form a dataset containing about 500 members. The phylogeny of spermatophyte functional STSs was constructed based on the structural comparative analysis to reveal the sequence–structure–function relationships. We propose the evolutionary history of plant sesquiterpene skeletons, from chain structure to small rings, followed by large rings for the first time and put forward a more detailed function-driven hypothesis. Then, the evolutionary origins and history of spermatophyte STSs are also discussed. In addition, three newly identified STSs CaSTS2, CaSTS3, and CaSTS4 were analyzed in this functional evolutionary system, and their germacrene D products were consistent with the functional prediction. This demonstrates an application of the structure-based phylogeny in predicting STS function. This work will help us to understand evolutionary patterns and dynamics of plant sesquiterpenes and STSs and screen or design STSs with specific product profiles as functional elements for synthetic biology application.

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Resurrecting embryos of the tuatara, Sphenodon punctatus , to resolve vertebrate phallus evolution

Biology Letters ◽

10.1098/rsbl.2015.0694 ◽

2015 ◽

Vol 11 (10) ◽

pp. 20150694 ◽

Cited By ~ 16

Author(s):

Thomas J. Sanger ◽

Marissa L. Gredler ◽

Martin J. Cohn

Keyword(s):

Evolutionary History ◽

Three Dimensional ◽

External Genitalia ◽

Evolutionary Origin ◽

Victorian Era ◽

Evolutionary Origins ◽

Genital Development ◽

Dimensional Reconstruction ◽

Sphenodon Punctatus ◽

History Of

The breadth of anatomical and functional diversity among amniote external genitalia has led to uncertainty about the evolutionary origins of the phallus. In several lineages, including the tuatara, Sphenodon punctatus , adults lack an intromittent phallus, raising the possibility that the amniote ancestor lacked external genitalia and reproduced using cloacal apposition. Accordingly, a phallus may have evolved multiple times in amniotes. However, similarities in development across amniote external genitalia suggest that the phallus may have a single evolutionary origin. To resolve the evolutionary history of amniote genitalia, we performed three-dimensional reconstruction of Victorian era tuatara embryos to look for embryological evidence of external genital initiation. Despite the absence of an intromittent phallus in adult tuataras, our observations show that tuatara embryos develop genital anlagen. This illustrates that there is a conserved developmental stage of external genital development among all amniotes and suggests a single evolutionary origin of amniote external genitalia.

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