scholarly journals Protofeathers were likely to have existed within the common ancestor of dinosaurs

2015 ◽  
Author(s):  
Chan-gyu Yun
Keyword(s):  
Evolutionary History ◽  
Common Ancestor ◽  
Whole Body ◽  
Collagen Fibres ◽  
History Of ◽  
The Common

In this paper, I comment on Barrett et al. (2015) "Evolution of dinosaur epidermal structures". Though the original authors made some very interesting results, the conclusions made by them are likely influenced by inappropriate or incorrect assumptions such as very little preserved skin fragments represent whole body covering or dinosaurian integumentary structures might represent a degraded collagen fibres. Therefore, their result might represent small size of current datas or preservational bias rather than actual evolutionary history of dinosaurian feathers.

scholarly journals Protofeathers were likely to have existed within the common ancestor of dinosaurs

2015 ◽  
Author(s):  
Chan-gyu Yun
Keyword(s):  
Evolutionary History ◽  
Common Ancestor ◽  
Whole Body ◽  
Collagen Fibres ◽  
History Of ◽  
The Common

In this paper, I comment on Barrett et al. (2015) "Evolution of dinosaur epidermal structures". Though the original authors made some very interesting results, the conclusions made by them are likely influenced by inappropriate or incorrect assumptions such as very little preserved skin fragments represent whole body covering or dinosaurian integumentary structures might represent a degraded collagen fibres. Therefore, their result might represent small size of current datas or preservational bias rather than actual evolutionary history of dinosaurian feathers.

Bridging Darwin's Origin of Species & Wegener's Origin of Continents and Oceans:

2016 ◽  
Vol 78 (1) ◽  
pp. 24-33 ◽  
Author(s):  
Cristina Sousa
Keyword(s):  
Evolutionary History ◽  
Charles Darwin ◽  
Common Ancestor ◽  
Teaching Strategy ◽  
Origin Of Species ◽  
History Of ◽  
The Common ◽  
Research And Education ◽  
Evolution By Natural Selection ◽  
Biology Research

The common ancestor and evolution by natural selection, concepts introduced by Charles Darwin, constitute the central core of biology research and education. However, students generally struggle to understand these concepts and commonly form misconceptions about them. To help teachers select the most revelant portions of Darwin's work, I suggest some sentences from On the Origin of Species and briefly discuss their implications. I also suggest a teaching strategy that uses history of science and curriculum crosscutting concepts (cause and effect) that constitute the framework to explain the evolutionary history of ratites (flightless birds) as described by Darwin, starting in the Jurassic, with the breakup of Gondwanaland, as first described by Alfred Wegener in The Origin of Continents and Oceans.

First North African record of a melanistic common genet (Genetta genetta Linnaeus, 1758)

Mammalia ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Mourad Ahmim ◽  
Hafid Aroudj ◽  
Farouk Aroudj ◽  
Saaid Saidi ◽  
Samir Aroudj
Keyword(s):  
North Africa ◽  
Evolutionary History ◽  
North African ◽  
Mammal Species ◽  
Genetta Genetta ◽  
History Of ◽  
The Common ◽  
True Occurrence

Abstract The common genet (Genetta genetta Linnaeus, 1758) is a rare and protected mammal species in Algeria. We report the first melanistic individual of this species ever recorded in North Africa. Such animals have only been recorded in Spain and Portugal so far. It is unclear why melanistic common genets seem to be so rare in its African range. More research is needed to determine the true occurrence of melanistic individuals, and what the evolutionary history of melanism is in common genets.

scholarly journals Evolutionary history of dimethylsulfoniopropionate (DMSP) demethylation enzyme DmdA in marine bacteria

2019 ◽  
Author(s):  
Laura Hernández ◽  
Alberto Vicens ◽  
Luis Enrique Eguiarte ◽  
Valeria Souza ◽  
Valerie De Anda ◽  
...  
Keyword(s):  
Gene Family ◽  
Evolutionary History ◽  
Common Ancestor ◽  
Functional Divergence ◽  
Gene Families ◽  
Recent Common Ancestor ◽  
Common Ancestry ◽  
Demethylation Pathway ◽  
History Of ◽  
New Gene

ABSTRACTDimethylsulfoniopropionate (DMSP), an osmolyte produced by oceanic phytoplankton, is predominantly degraded by bacteria belonging to the Roseobacter lineage and other marine Alphaproteobacteria via DMSP-dependent demethylase A protein (DmdA). To date, the evolutionary history of DmdA gene family is unclear. Some studies indicate a common ancestry between DmdA and GcvT gene families and a co-evolution between Roseobacter and the DMSP-producing-phytoplankton around 250 million years ago (Mya). In this work, we analyzed the evolution of DmdA under three possible evolutionary scenarios: 1) a recent common ancestor of DmdA and GcvT, 2) a coevolution between Roseobacter and the DMSP-producing-phytoplankton, and 3) pre-adapted enzymes to DMSP prior to Roseobacter origin. Our analyses indicate that DmdA is a new gene family originated from GcvT genes by duplication and functional divergence driven by positive selection before a coevolution between Roseobacter and phytoplankton. Our data suggest that Roseobacter acquired dmdA by horizontal gene transfer prior to exposition to an environment with higher DMSP. Here, we propose that the ancestor that carried the DMSP demethylation pathway genes evolved in the Archean, and was exposed to a higher concentration of DMSP in a sulfur rich atmosphere and anoxic ocean, compared to recent Roseobacter ecoparalogs (copies performing the same function under different conditions), which should be adapted to lower concentrations of DMSP.

scholarly journals The evolutionary history of the two karyotypic groups of the common shrew, Sorex araneus, in Poland

Heredity ◽  
2002 ◽  
Vol 88 (4) ◽  
pp. 235-242 ◽  
Author(s):  
M Ratkiewicz ◽  
S Fedyk ◽  
A Banaszek ◽  
L Gielly ◽  
W Chȩtnicki ◽  
...  
Keyword(s):  
Evolutionary History ◽  
Common Shrew ◽  
Sorex Araneus ◽  
History Of ◽  
The Common ◽  
Common Shrew Sorex Araneus

scholarly journals Evolutionary History and Activity of RNase H1-Like Proteins in Arabidopsis thaliana

2020 ◽  
Vol 61 (6) ◽  
pp. 1107-1119
Author(s):  
Jan Kuciński ◽  
Sebastian Chamera ◽  
Aleksandra Kmera ◽  
M Jordan Rowley ◽  
Sho Fujii ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Embryonic Development ◽  
Evolutionary History ◽  
Common Ancestor ◽  
Normal Growth ◽  
Plastid Dna ◽  
Growth Conditions ◽  
Replicative Stress ◽  
The Common ◽  
Rna:Dna Hybrids

Abstract RNase H1 is an endonuclease specific toward the RNA strand of RNA:DNA hybrids. Members of this protein family are present in most living organisms and are essential for removing RNA that base pairs with DNA. It prevents detrimental effects of RNA:DNA hybrids and is involved in several biological processes. Arabidopsis thaliana has been previously shown to contain three genes encoding RNase H1 proteins that localize to three distinct cellular compartments. We show that these genes originate from two gene duplication events. One occurred in the common ancestor of dicots and produced nuclear and organellar RNase H1 paralogs. Second duplication occurred in the common ancestor of Brassicaceae and produced mitochondrial- and plastid-localized proteins. These proteins have the canonical RNase H1 activity, which requires at least four ribonucleotides for endonucleolytic digestion. Analysis of mutants in the RNase H1 genes revealed that the nuclear RNH1A and mitochondrial RNH1B are dispensable for development under normal growth conditions. However, the presence of at least one organellar RNase H1 (RNH1B or RNH1C) is required for embryonic development. The plastid-localized RNH1C affects plastid DNA copy number and sensitivity to replicative stress. Our results present the evolutionary history of RNH1 proteins in A. thaliana, demonstrate their canonical RNase H1 activity and indicate their role in early embryonic development.

scholarly journals Tribalism Is Human Nature

2019 ◽  
Vol 28 (6) ◽  
pp. 587-592 ◽  
Author(s):  
Cory J. Clark ◽  
Brittany S. Liu ◽  
Bo M. Winegard ◽  
Peter H. Ditto
Keyword(s):  
Evolutionary History ◽  
Cognitive Biases ◽  
Meta Analysis ◽  
Human Cognition ◽  
Partisan Bias ◽  
Selective Pressures ◽  
Group Loyalty ◽  
History Of ◽  
The Common ◽  
Political Spectrum

Humans evolved in the context of intense intergroup competition, and groups comprised of loyal members more often succeeded than groups comprised of nonloyal members. Therefore, selective pressures have sculpted human minds to be tribal, and group loyalty and concomitant cognitive biases likely exist in all groups. Modern politics is one of the most salient forms of modern coalitional conflict and elicits substantial cognitive biases. The common evolutionary history of liberals and conservatives gives little reason to expect protribe biases to be higher on one side of the political spectrum than the other. This evolutionarily plausible null hypothesis has been supported by recent research. In a recent meta-analysis, liberals and conservatives showed similar levels of partisan bias, and several protribe cognitive tendencies often ascribed to conservatives (e.g., intolerance toward dissimilar other people) were found in similar degrees in liberals. We conclude that tribal bias is a natural and nearly ineradicable feature of human cognition and that no group—not even one’s own—is immune.

scholarly journals Portiera Gets Wild: Genome Instability Provides Insights into the Evolution of Both Whiteflies and Their Endosymbionts

2020 ◽  
Vol 12 (11) ◽  
pp. 2107-2124
Author(s):  
Diego Santos-Garcia ◽  
Natividad Mestre-Rincon ◽  
David Ouvrard ◽  
Einat Zchori-Fein ◽  
Shai Morin
Keyword(s):  
Evolutionary History ◽  
Common Ancestor ◽  
Genome Instability ◽  
Rare Event ◽  
Essential Amino Acids ◽  
Phylogenetic Framework ◽  
The Common ◽  
Phloem Feeding ◽  
New Framework ◽  
Time Point

Abstract Whiteflies (Hemiptera: Sternorrhyncha: Aleyrodidae) are a superfamily of small phloem-feeding insects. They rely on their primary endosymbionts "Candidatus Portiera aleyrodidarum" to produce essential amino acids not present in their diet. Portiera has been codiverging with whiteflies since their origin and therefore reflects its host’s evolutionary history. Like in most primary endosymbionts, the genome of Portiera stays stable across the Aleyrodidae superfamily after millions of years of codivergence. However, Portiera of the whitefly Bemisia tabaci has lost the ancestral genome order, reflecting a rare event in the endosymbiont evolution: the appearance of genome instability. To gain a better understanding of Portiera genome evolution, identify the time point in which genome instability appeared and contribute to the reconstruction of whitefly phylogeny, we developed a new phylogenetic framework. It targeted five Portiera genes and determined the presence of the DNA polymerase proofreading subunit (dnaQ) gene, previously associated with genome instability, and two alternative gene rearrangements. Our results indicated that Portiera gene sequences provide a robust tool for studying intergenera phylogenetic relationships in whiteflies. Using these new framework, we found that whitefly species from the Singhiella, Aleurolobus, and Bemisia genera form a monophyletic tribe, the Aleurolobini, and that their Portiera exhibit genome instability. This instability likely arose once in the common ancestor of the Aleurolobini tribe (at least 70 Ma), drawing a link between the appearance of genome instability in Portiera and the switch from multibacteriocyte to a single-bacteriocyte mode of inheritance in this tribe.

scholarly journals The evolutionary history of haptophytes and cryptophytes: phylogenomic evidence for separate origins

2012 ◽  
Vol 279 (1736) ◽  
pp. 2246-2254 ◽  
Author(s):  
Fabien Burki ◽  
Noriko Okamoto ◽  
Jean-François Pombert ◽  
Patrick J. Keeling
Keyword(s):  
Evolutionary History ◽  
Expressed Sequence Tag ◽  
Level Data ◽  
Guillardia Theta ◽  
History Of ◽  
The Common ◽  
Genome Level ◽  
Phylogenomic Analyses ◽  
New Hypothesis ◽  
Expressed Sequence

An important missing piece in the puzzle of how plastids spread across the eukaryotic tree of life is a robust evolutionary framework for the host lineages. Four assemblages are known to harbour plastids derived from red algae and, according to the controversial chromalveolate hypothesis, these all share a common ancestry. Phylogenomic analyses have consistently shown that stramenopiles and alveolates are closely related, but haptophytes and cryptophytes remain contentious; they have been proposed to branch together with several heterotrophic groups in the newly erected Hacrobia. Here, we tested this question by producing a large expressed sequence tag dataset for the katablepharid Roombia truncata , one of the last hacrobian lineages for which genome-level data are unavailable, and combined this dataset with the recently completed genome of the cryptophyte Guillardia theta to build an alignment composed of 258 genes. Our analyses strongly support haptophytes as sister to the SAR group, possibly together with telonemids and centrohelids. We also confirmed the common origin of katablepharids and cryptophytes, but these lineages were not related to other hacrobians; instead, they branch with plants. Our study resolves the evolutionary position of haptophytes, an ecologically critical component of the oceans, and proposes a new hypothesis for the origin of cryptophytes.

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