scholarly journals Genetic differentiation in the genus Characodon: implications for conservation and taxonomy

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11492
Author(s):  
Rosa G. Beltrán-López ◽  
Rodolfo Pérez-Rodríguez ◽  
Ofelia C. Montañez-García ◽  
Juan M. Artigas-Azas ◽  
Michael Köck ◽  
...  
Keyword(s):  
Genetic Differentiation ◽  
Evolutionary History ◽  
Genetic Distances ◽  
Genetic Groups ◽  
Evolutionary Significant Units ◽  
Significant Genetic Structure ◽  
D Loop ◽  
History Of ◽  
The Subject ◽  
Phylogeographic Study

The subfamily Goodeinae is a group of fishes endemic to the Mexican highlands. Most of the species are restricted to small and isolated streams or springs. Within this subfamily, the genus Characodon is the earliest diverging lineage of which three species have been described: C. lateralis, C. audax, and C. garmani, with the latter, considered extinct. Characodon lateralis and C. audax are classed as endangered, and have been the subject of taxonomic controversy since their description: previous studies have recognized a genetic differentiation in two groups separated by the El Salto waterfall, but morphological analyses contradict these genetic results. We perform a phylogeographic study using the mitochondrial cytb gene and d-loop region to elucidate the evolutionary history of C. lateralis and C. audax. The results with both markers show the presence of two highly differentiated haplogroups; one distributed north and the other distributed south of the waterfall, with genetic distances of 1.7 and 13.1% with cytb and d-loop respectively, and divergence calculated to have occurred 1.41 Mya. Significant genetic structure was found within each haplogroup and suggests the existence of at least four Evolutionary Significant Units (ESUs) within the examined populations. The possible processes identified as contributing to the formation of differentiated genetic groups are isolation, low population size, recurrent bottlenecks, and the strong sexual selection exhibited by the genus.

scholarly journals Phylogeography of high Andean killifishes Orestias (Teleostei: Cyprinodontidae) in Caquena and Lauca sub-basins of the Altiplano (Chile): mitochondrial and nuclear analysis of an endangered fish

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11917
Author(s):  
Violeta Cárcamo-Tejer ◽  
Irma Vila ◽  
Francisco Llanquín-Rosas ◽  
Alberto Sáez-Arteaga ◽  
Claudia Guerrero-Jiménez
Keyword(s):  
Evolutionary History ◽  
Andes Mountains ◽  
Endangered Fish ◽  
The Andes ◽  
Genetic Groups ◽  
Biogeographic History ◽  
D Loop ◽  
History Of ◽  
Nuclear Microsatellite ◽  
Genic Diversity

From the early Miocene, the uplift of the Andes Mountains, intense volcanic activity and the occurrence of successive periods of dryness and humidity would have differentially influenced the modification of Altiplano watersheds, and consequently the evolutionary history of the taxa that live there. We analyzed Orestias populations from the Caquena and Lauca Altiplanic sub-basins of northern Chile to determine their genetic differentiation and relationship to their geographical distribution using mitochondrial (D-loop) and nuclear (microsatellite) molecular markers and to reconstruct its biogeographic history on these sub-basins. The results allowed reconstructing and reevaluating the evolutionary history of the genus in the area; genic diversity and differentiation together with different founding genetic groups suggest that Orestias have been spread homogeneously in the study area and would have experienced local disturbances that promoted isolation and diversification in restricted zones of their distribution.

scholarly journals The dynamic evolutionary history of genome size in North American woodland salamanders

Genome ◽  
2017 ◽  
Vol 60 (4) ◽  
pp. 285-292 ◽  
Author(s):  
Catherine E. Newman ◽  
T. Ryan Gregory ◽  
Christopher C. Austin
Keyword(s):  
Genome Size ◽  
Evolutionary History ◽  
Future Studies ◽  
Plethodontid Salamanders ◽  
Genome Size Evolution ◽  
Size Evolution ◽  
History Of ◽  
Large Genome Size ◽  
Uncertain Future ◽  
Phylogeographic Study

The genus Plethodon is the most species-rich salamander genus in North America, and nearly half of its species face an uncertain future. It is also one of the most diverse families in terms of genome sizes, which range from 1C = 18.2 to 69.3 pg, or 5–20 times larger than the human genome. Large genome size in salamanders results in part from accumulation of transposable elements and is associated with various developmental and physiological traits. However, genome sizes have been reported for only 25% of the species of Plethodon (14 of 55). We collected genome size data for Plethodon serratus to supplement an ongoing phylogeographic study, reconstructed the evolutionary history of genome size in Plethodontidae, and inferred probable genome sizes for the 41 species missing empirical data. Results revealed multiple genome size changes in Plethodon: genomes of western Plethodon increased, whereas genomes of eastern Plethodon decreased, followed by additional decreases or subsequent increases. The estimated genome size of P. serratus was 21 pg. New understanding of variation in genome size evolution, along with genome size inferences for previously unstudied taxa, provide a foundation for future studies on the biology of plethodontid salamanders.

Genetic differentiation and evolutionary history of the circumpolar species Ophiura sarsii and subspecies Ophiura sarsii vadicola (Ophiurida: Ophiuridae)

2020 ◽  
Vol 197 ◽  
pp. 104085
Author(s):  
Yixuan Li ◽  
Yue Dong ◽  
Qinzeng Xu ◽  
Shiliang Fan ◽  
Heshan Lin ◽  
...  
Keyword(s):  
Genetic Differentiation ◽  
Evolutionary History ◽  
History Of

scholarly journals Pattern, process, inference and prediction in extinction biology

2017 ◽  
Vol 13 (1) ◽  
pp. 20160828 ◽  
Author(s):  
Barry W. Brook ◽  
John Alroy
Keyword(s):  
Natural Science ◽  
Evolutionary History ◽  
Extinction Risk ◽  
Special Issue ◽  
Effective Protection ◽  
Practical Applications ◽  
Recent Developments ◽  
History Of ◽  
The Subject ◽  
Patterns And Processes

Extinction is a key feature of the evolutionary history of life, and assessments of extinction risk are essential for the effective protection of biodiversity. The goal in assembling this special issue of Biology Letters was to highlight problems and questions at the research frontier of extinction biology, with an emphasis on recent developments in the methodology of inferring the patterns and processes of extinction from a background of often noisy and sparse data. In selecting topics, we sought to illustrate how extinction is not simply a self-evident phenomenon, but the subject of a dynamic and quantitatively rigorous field of natural science, with practical applications to conservation.

Morphology, songs and genetics identify two new cicada species from Morocco: Tettigettalna afroamissa sp. nov. and Berberigetta dimelodica gen. nov. & sp. nov. (Hemiptera: Cicadettini)

Zootaxa ◽  
2017 ◽  
Vol 4237 (3) ◽  
pp. 517
Author(s):  
GONÇALO JOÃO COSTA ◽  
VERA L. NUNES ◽  
EDUARDO MARABUTO ◽  
RAQUEL MENDES ◽  
TELMA G. LAURENTINO ◽  
...  
Keyword(s):  
Evolutionary History ◽  
New Genus ◽  
Acoustic Analysis ◽  
Phylogenetic Analyses ◽  
Habitat Preferences ◽  
Dna Barcode ◽  
Genetic Data ◽  
North African ◽  
History Of ◽  
The Subject

Morocco has been the subject of very few expeditions on the last century with the objective of studying small cicadas. In the summer of 2014 an expedition was carried out to Morocco to update our knowledge with acoustic recordings and genetic data of these poorly known species. We describe here two new small-sized cicadas that could not be directly assigned to any species of North African cicadas: Tettigettalna afroamissa sp. nov. and Berberigetta dimelodica gen. nov. & sp. nov. In respect to T. afroamissa it is the first species of the genus to be found outside Europe and we frame this taxon within the evolutionary history of the genus. Acoustic analysis of this species allows us to confidently separate T. afroamissa from its congeners. With B. dimelodica, a small species showing a remarkable calling song characterized by an abrupt frequency modulation, a new genus had to be erected. Bayesian inference and maximum likelihood phylogenetic analyses with DNA-barcode sequences of Cytochrome C Oxidase 1 support the monophyly of both species, their distinctness and revealed genetic structure within B. dimelodica. Alongside the descriptions we also provide GPS coordinates of collection points, distributions and habitat preferences. 

scholarly journals Mass loss and evolution of massive stars

1981 ◽  
Vol 59 ◽  
pp. 229-253
Author(s):  
C. Chiosi
Keyword(s):  
Mass Loss ◽  
Stellar Wind ◽  
Evolutionary History ◽  
Massive Stars ◽  
Observational Evidence ◽  
Common Occurrence ◽  
Theoretical Understanding ◽  
The Past ◽  
History Of ◽  
The Subject

In the past few years both growing observational evidence and theoretical understanding have shown that mass loss by stellar wind is a common occurrence in the evolutionary history of many types of star. Recent reviews on the subject may be found in Conti (1978), Cassinelli (1979), Conti and Mc Cray (1980), Hutchings (1980a), de Loore (1979, 1980) and Sreenivasan (1979).Therefore, in this paper we will concentrate only on those observational and theoretical aspects of the problem that demand further investigation.

scholarly journals IV. The pelmatoporinæ, an essay on the evolution of a group of cretaceous polyzoa

1920 ◽  
Vol 209 (360-371) ◽  
pp. 191-228 ◽  
Keyword(s):  
Evolutionary History ◽  
British Museum ◽  
Radical Species ◽  
Large Size ◽  
Evolutionary Scheme ◽  
The Status ◽  
History Of ◽  
The Subject ◽  
Complex Forms ◽  
The Many

Having spent many years in working through the Cretaceous Cribrimorph material in the British Museum, and, consequently, the literature of the subject, I was forced to the conclusion that various Cribrimorph stocks had independently arisen over and over again from Membranimorph ancestors, had run through a more or less similar evolution, and, finally, become extinct; so that the many forms described under Cribrilina, Membraniporella , and other Recent genera were really in no way closely related to these, and the Cretaceous Cribrimorph forms, in consequence, needed at lea st a generic nomenclature of their own. These Cretaceous forms fell under ten main stocks, between which no direct relationship could be discovered, and whose common ancestor must be sought far back among the primitive Membranimorphs; so that it did not seem too much to claim for each of these main stocks the status of a family. Within certain families were several well-defined groups, which, nevertheless, in each case had features in common, rendering it possible for all to have been derived from a common Cribrimorph ancestor; it seem ed permissible, therefore, to regard these groups as subfamilies. Thus a complete evolutionary classification was drawn up for the Cretaceous Cribrimorphs, and this, in the tersest possible form, was published in the ‘Annals and Magazine of Natural History (Lang, 1916). Since the whole evolutionary scheme was implicit in the tabular analysis, it was hoped that this would be lucid enough to be acceptable without further explanation. From, various criticisms, it appears that this is not so, and the opportunity has been taken in this essay to select one subfamily and expand the condensed account into a fuller statement. The subfamily Pelmatoporinæ was chosen partly because of its large size, and partly because it illustrates so fully the principles of evolution exhibited by the Cretaceous Cribrimorphs generally; but other subfamilies would serve the same purpose nearly as well. The morphology of the group is the first consideration; and since it is founded on the structure of the species Pelmatopora calceata , which closely approximates to the supposed ancestral form, this radical species is considered in some detail. Then, after examining the evolutionary aim of Cretaceous Cribrimorphs as a whole, we are in a position to appreciate the general evolutionary history of each character of the radical species, as it proceeds from the less to the more complex forms in the several lineages. Next, peculiar modifications of certain characters are described, giving the criteria for generic distinctions; then the evolution of forms within each genus. The results are compared with those obtained by W. K. Spencer in his work on Cretaceous Asteroidea. Next, the stratigraphical distribution of the forms is examined to see how far this corroborates the relationships established on morphic evidence; and, finally, the evidence of recapitulation, as shown in the colonial development (Astogeny), is brought to bear in connection with the other two criteria of relationships already examined.

scholarly journals The evolutionary history of manatees told by their mitogenomes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Érica Martinha Silva de Souza ◽  
Lucas Freitas ◽  
Elisa Karen da Silva Ramos ◽  
Giovanna Selleghin-Veiga ◽  
Michelle Carneiro Rachid-Ribeiro ◽  
...  
Keyword(s):  
Late Miocene ◽  
Evolutionary History ◽  
Amazon Basin ◽  
Sister Group ◽  
Protein Coding ◽  
Posterior Mean ◽  
D Loop ◽  
History Of ◽  
West Indian Manatee ◽  
Rna Genes

AbstractThe manatee family encompasses three extant congeneric species: Trichechus senegalensis (African manatee), T. inunguis (Amazonian manatee), and T. manatus (West Indian manatee). The fossil record for manatees is scant, and few phylogenetic studies have focused on their evolutionary history. We use full mitogenomes of all extant manatee species to infer the divergence dates and biogeographical histories of these species and the effect of natural selection on their mitogenomes. The complete mitochondrial genomes of T. inunguis (16,851 bp), T. senegalensis (16,882 bp), and T. manatus (16,882 bp), comprise 13 protein-coding genes, 2 ribosomal RNA genes (rRNA - 12S and 16S), and 22 transfer RNA genes (tRNA), and (D-loop/CR). Our analyses show that the first split within Trichechus occurred during the Late Miocene (posterior mean 6.56 Ma and 95% HPD 3.81–10.66 Ma), followed by a diversification event in the Plio-Pleistocene (posterior mean 1.34 Ma, 95% HPD 0.1–4.23) in the clade composed by T. inunguis and T. manatus; T. senegalensis is the sister group of this clade with higher support values (pp > 0.90). The branch-site test identified positive selection on T. inunguis in the 181st position of the ND4 amino acid gene (LRT = 6.06, p = 0.0069, BEB posterior probability = 0.96). The ND4 gene encodes one subunit of the NADH dehydrogenase complex, part of the oxidative phosphorylation machinery. In conclusion, our results provide novel insight into the evolutionary history of the Trichechidae during the Late Miocene, which was influenced by geological events, such as Amazon Basin formation.

scholarly journals GENETIC CHANGE AND RATES OF CLADOGENESIS

Genetics ◽  
1975 ◽  
Vol 81 (4) ◽  
pp. 757-773
Author(s):  
John C Avise ◽  
Francisco J Ayala
Keyword(s):  
Genetic Differentiation ◽  
Genetic Distance ◽  
Genetic Divergence ◽  
Natural Populations ◽  
Genetic Distances ◽  
Genetic Change ◽  
The Other ◽  
Limited Information ◽  
History Of ◽  
The Relationship

ABSTRACT Models are introduced which predict ratios of mean levels of genetic divergence in species-rich versus species-poor phylads under two competing assumptions: (1) genetic differentiation is a function of time, unrelated to the number of cladogenetic events and (2) genetic differentiation is proportional to the number of speciation events in the group. The models are simple, general, and biologically real, but not precise. They lead to qualitatively distinct predictions about levels of genetic divergence depending upon the relationship between rates of speciation and amount of genetic change. When genetic distance between species is a function of time, mean genetic distances in speciose and depauperate phylads of equal evolutionary age are very similar. On the contrary, when genetic distance is a function of the number of speciations in the history of a phylad, the ratio of mean genetic distances separating species in speciose versus depauperate phylads is greater than one, and increases rapidly as the frequency of speciations in one group relative to the other increases. The models may be tested with data from natural populations to assess (1) possible correlations between rates of anagenesis and cladogenesis and (2) the amount of genetic differentiation accompanying the speciation process. The data collected in electrophoretic surveys and other kinds of studies can be used to test the predictions of the models. For this purpose genetic distances need to be measured in speciose and depauperate phylads of equal evolutionary age. The limited information presently available agrees better with the model predicting that genetic change is primarily a function of time, and is not correlated with rates of speciation. Further testing of the models is, however, required before firm conclusions can be drawn.

scholarly journals Study on genetic variations of the D-loop region in three Vietnamese ethnic groups Kinh, Lolo and Lahu

2020 ◽  
Vol 18 (2) ◽  
pp. 231-238
Author(s):  
Nguyen Thuy Duong ◽  
Nguyen Van Phong ◽  
Nguyen Thy Ngoc ◽  
Nong Van Hai
Keyword(s):  
Ethnic Groups ◽  
Genetic Distances ◽  
Genetic Variations ◽  
Language Group ◽  
Nucleotide Polymorphisms ◽  
Loop Region ◽  
Minority Ethnic Groups ◽  
Mtdna Sequence ◽  
D Loop ◽  
History Of

Mitochondrial DNA (mtDNA) sequence analysis has been widely used to investigate population genetic and evolutional history of different ethnic groups worldwide. In this study, the D-loop region of 119 Vietnamese individuals belonging to three different ethnic groups was sequenced and compared with reference mtDNA on rCRS for genetic variations. Total 218 genetic polymorphisms were found in this population, among which 48 variations appeared with frequencies of more than 0.1. Further statistical analysis showed that there were 23, 13 and 24 single nucleotide polymorphisms (SNP) distributed differently between Kinh vs. Lolo, Kinh  vs. Lahu , and Lolo  vs. Lahu groups, respectively. The mean pairwise genetic distances between each pair of ethnic groups were 0.0101, 0.0098 and 0.0092 for Kinh - Lolo, Kinh - Lahu, Lolo - Lahu, respectively. This indicated that although the Lolo and Lahu ethnic groups both belong to the Tibeto-Burman language group, the genetic distance between them was no closer than the genetic distances between them and the Kinh group of the Viet-Muong (Austroasiatic) language group. This study was the first research on the D-loop region of the Lolo and Lahu populations in Vietnam. These results provided more data for exploring the genetic background and the history of those ethnic groups as well as other minority ethnic groups in Vietnam.

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