Cytogenetics of beavers: a case of speciation by monobrachial centric fusions

Genome ◽  
1991 ◽  
Vol 34 (3) ◽  
pp. 324-328 ◽  
Author(s):  
O. G. Ward ◽  
A. S. Graphodatsky ◽  
D. H. Wurster-Hill ◽  
V. R. Eremina ◽  
J. P. Park ◽  
...  
Keyword(s):  
Reproductive Isolation ◽  
North American ◽  
Karyotype Evolution ◽  
Castor Canadensis ◽  
The Other ◽  
Castor Fiber ◽  
Isolated Populations

A comparison of G-banded chromosomes of four North American beavers, Castor canadensis (two males, two females), and four Eurasian beavers, Castor fiber (two males, two females), revealed that extensive monobrachial centric fusions distinguished the karyotypes of the two species. The complex multivalent formations that would occur in meiosis of a hypothetical hybrid would be expected to produce unbalanced gametes and postmating reproductive isolation. Thus, neither species was derived from the other; rather, they likely were derived from isolated populations in which some of the acrocentrics fused independently to produce monobrachial homology.Key words: beaver, chromosomes, karyotype evolution, monobrachial rearrangements, reproductive isolation.

scholarly journals Interspecies Chromosome Mapping in Caprimulgiformes, Piciformes, Suliformes, and Trogoniformes (Aves): Cytogenomic Insight into Microchromosome Organization and Karyotype Evolution in Birds

Cells ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 826
Author(s):  
Rafael Kretschmer ◽  
Marcelo Santos de Souza ◽  
Ivanete de Oliveira Furo ◽  
Michael N. Romanov ◽  
Ricardo José Gunski ◽  
...  
Keyword(s):  
Convergent Evolution ◽  
Karyotype Evolution ◽  
Rare Events ◽  
Rare Event ◽  
Chromosome Mapping ◽  
The Other ◽  
Other Hand ◽  
Interchromosomal Rearrangement ◽  
Insight Into ◽  
Phalacrocorax Brasilianus

Interchromosomal rearrangements involving microchromosomes are rare events in birds. To date, they have been found mostly in Psittaciformes, Falconiformes, and Cuculiformes, although only a few orders have been analyzed. Hence, cytogenomic studies focusing on microchromosomes in species belonging to different bird orders are essential to shed more light on the avian chromosome and karyotype evolution. Based on this, we performed a comparative chromosome mapping for chicken microchromosomes 10 to 28 using interspecies BAC-based FISH hybridization in five species, representing four Neoaves orders (Caprimulgiformes, Piciformes, Suliformes, and Trogoniformes). Our results suggest that the ancestral microchromosomal syntenies are conserved in Pteroglossus inscriptus (Piciformes), Ramphastos tucanus tucanus (Piciformes), and Trogon surrucura surrucura (Trogoniformes). On the other hand, chromosome reorganization in Phalacrocorax brasilianus (Suliformes) and Hydropsalis torquata (Caprimulgiformes) included fusions involving both macro- and microchromosomes. Fissions in macrochromosomes were observed in P. brasilianus and H. torquata. Relevant hypothetical Neognathae and Neoaves ancestral karyotypes were reconstructed to trace these rearrangements. We found no interchromosomal rearrangement involving microchromosomes to be shared between avian orders where rearrangements were detected. Our findings suggest that convergent evolution involving microchromosomal change is a rare event in birds and may be appropriate in cytotaxonomic inferences in orders where these rearrangements occurred.

scholarly journals Eurasian and North American phylogeny of Turolian hipparionine horses (Perissodactyla, Mammalia) in China

1992 ◽  
Vol 6 ◽  
pp. 305-305
Author(s):  
Mahito Watabe
Keyword(s):  
North America ◽  
North American ◽  
Northern China ◽  
Sensu Stricto ◽  
The Other ◽  
Dental Morphology ◽  
Facial Morphology ◽  
Open Land ◽  
Specialized Form ◽  
Eastern Half

The late Miocene Chinese hipparions are morphologically diversified showing similarity to both western Old World's and North American forms. Two Chinese taxa that are phylogenetically related to western Old World's forms are Hipparion fossatum (= H. forstende) from Baode (Shanxi) and H. hippidiodus from Qingyang (Gansu) and Baode. The former is related to H. mediterraneum and the latter to H. urmiense - platygenys from the Turolian localities in the western Old World. H. fossatum and H. hippidiodus are associated with the “dorcadoides” (open-land) and “mixed” faunas in northern China. Hipparion fossatum that is characterized by POF located close to the orbit co-occurs with large and morphologically specialized form, H. dermatorhinum in Baode (Loc.30). H. hippidiodus with reduced POF is discovered with smaller H. coelophyes in Loc. 43, 44 (Baode) and Loc. 115 (Gansu).The hipparions associated with the “gaudryi” (forest) fauna are characterized by well defined and small POF located far from the orbit. Those forms are: H. platyodus from Loc. 70; H. ptychodus from Loc. 73; H. tylodus from Hsi-Liang in Yushe - Wuxiang basins; and H. sefvei from Loc. 12 at Xin-an in Henan province. H. coelophyes from Baode (Loc.43 & 44) and Qingyang (Loc. 115) also show similar facial morphology to the these forms, although it has small size and shallow POF. Those forms are similar in facial and dental morphology to Hipparion sensu stricto and some species of Cormohipparion in North America.The assemblages of Chinese hipparions are composed of two groups whose members are phylogenetically similar to the forms from both western part of Eurasia and North America. The “gaudryi” fauna is considered younger than the other two on the basis of faunal analyses. The similarity in hipparionine taxonomy between northern China and North America in the latest Miocene is an evidences for possible faunal interchange(s) occurred during that period, as suggested by taxonomic analyses on carnivores and proboscideans in eastern half of Eurasia and North America.

Tunes That Bind: Paul J. Seelig, Eva Gauthier, Charles T. Griffes, and the Javanese Other

2009 ◽  
Vol 3 (2) ◽  
pp. 129-154
Author(s):  
HENRY SPILLER
Keyword(s):  
Identity Formation ◽  
North American ◽  
Raw Materials ◽  
Sense Of Self ◽  
The Other ◽  
Edward Said ◽  
Complex Relationship ◽  
East Indies ◽  
Dutch East Indies

AbstractThe powerful concept of orientalism has undergone considerable refinement since Edward Said popularized the term with his eponymous book in 1978. Orientalism typically is presented as a totalizing process that creates polar oppositions between a dominating West and a subordinate East. U.S. orientalisms, however, reflect uniquely North American approaches to identity formation that include assimilating characteristics usually associated with the Other. This article explores the complex relationship among three individuals—U.S. composer Charles T. Griffes, Canadian singer Eva Gauthier, and German-trained Dutch East Indies composer Paul J. Seelig—and how they exploited the same Javanese songs to lend legitimacy to their individual artistic projects. A comparison of Griffes's and Seelig's settings of a West Javanese tune (“Kinanti”) provides an especially clear example of how contrasting approaches manifest different orientalisms. Whereas Griffes accompanied the melody with stock orientalist gestures to express his own fascination with the exotic, Seelig used chromatic harmonies and a chorale-like texture to ground the melody in the familiar, translating rather than representing its Otherness. The tunes that bind Griffes, Gauthier, and Seelig are only the raw materials from which they created their own unique orientalisms, each with its own sense of self and its own Javanese others.

The speciation continuum and species relations between populations: in search of agreement between the theory and practice of systematics

2021 ◽  
pp. 173-179
Author(s):  
Oleksandr Zinenko
Keyword(s):  
Reproductive Isolation ◽  
Species Concept ◽  
Climatic Conditions ◽  
Point Of View ◽  
Theory And Practice ◽  
Hybrid Origin ◽  
Isolated Populations ◽  
As Species ◽  
Mitochondrial Cytochrome B ◽  
Traditional Taxonomy

From an evolutionary point of view, the achievement of species status by a group of populations is an ongoing process (except for rare cases of instantaneous speciation), during which isolated populations acquire traits and adaptations that minimize gene flow between them. However, depending on the group, the ways and timing of the gaining of reproductive isolation may be different. In such a complex group for systematics as small vipers (genus Vipera, subgenus Pelias), there are a number of problematic situations for species delimitation: the ability to form hybrids and hybrid populations between species, adaptive hybridization and hybrid speciation, and possible traces of reversed speciation, which indicate that complete and irreversible reproductive isolation may not be achieved at all. The effectiveness of reproductive isolation largely depends on external factors, mostly related to the range spatial structure, ecology of species in areas of sympatry, as well as climatic conditions and their changes, landscape dynamics, etc. The only species concept that allows to describe new species in the absence of reproductive isolation, recognizes the possibility of hybrid and reverse speciation — de Queiroz unified species concept — is practically unsuitable due to the need to consider as species a large number of isolated populations. Therefore, the solution is a conservative approach in practical taxonomy, which takes into account as a species criterion the ecological divergence of species, the possibility of their sympatric existence, which is usually achieved at 5% divergence of the mitochondrial cytochrome b gene. Stabilized hybrid populations occupying distinct ecological niche different from those of parental species also deserve recognition as species of hybrid origin. Not only species deserves to be protected, but also a distinguishable and diverged group of populations — Evolutionary Significant Unit (ESU) or subspecies in traditional taxonomy.

scholarly journals Typology and nuance: relativization

2020 ◽  
pp. 104-130
Author(s):  
Marianne Mithun
Keyword(s):  
North American ◽  
Large Scale ◽  
Relative Clauses ◽  
Spontaneous Speech ◽  
The Other ◽  
Stages Of Development ◽  
Linguistic Typology ◽  
The North

Much of linguistic typology is inherently categorical. In large-scale typological surveys, grammatical constructions, distinctions, and even variables are typically classified as present, absent, or embodying one of a set of specified options. This work is valuable for a multitude of purposes, and in many cases such categorization is sufficient. In others, we can advance our understanding further if we take a more nuanced approach, considering the extent to which a particular construction, distinction, or variable is installed in the grammar. An important tool for this approach is the examination of unscripted speech in context, complete with prosody. This point is illustrated here with Mohawk, an Iroquoian language indigenous to the North American Northeast. As will be seen, the two types of construction which might be identified as relative clauses are emergent, one less integrated into the grammar than the other. Examination of spontaneous speech indicates that the earliest stages of development are prosodic, as speakers shape their messages according to their communicative purposes at each moment.

scholarly journals Comparative analysis of populations of the Balkan endemic species Daphne malyana Blecic (Thymeleaceae)

2010 ◽  
Vol 62 (4) ◽  
pp. 1151-1162 ◽  
Author(s):  
Marina Juskovic ◽  
P. Vasiljevic ◽  
V. Randjelovic ◽  
V. Stevanovic ◽  
Branka Stevanovic
Keyword(s):  
Principal Component Analysis ◽  
Comparative Analysis ◽  
Endemic Species ◽  
Morphological Variability ◽  
Principal Component ◽  
Balkan Peninsula ◽  
Canonical Discriminant Analysis ◽  
The Other ◽  
Isolated Populations ◽  
Microclimate Conditions

Daphne malyana Blecic (Thymeleaceae) is an endemic species of the western part of the Balkan Peninsula, distributed in the mountains, canyons and gorges of N. Montenegro, E. Bosnia and W. Serbia. The comparative morphoanatomic investigations have included four distantly separated populations of the species D. malyana, i.e. two from Serbia, from the ravines of Sokoline and Vranjak on Mt. Tara, and two from Montenegro, in the canyons of the Tara and Piva rivers. Comparative morphoanatomical studies have shown the presence of general adaptive characteristics of a specific, conservative xeromorphic type, slightly differing in each population. Principal component analysis (PCA) and canonical discriminant analysis (CDA) of 20 morphoanatomical characteristics of the leaves and stems have shown a clear distinction between the populations from the river Piva canyon (Montenegro) and those from the Sokoline ravine (Serbia), on one side, and those of Vranjak gorge (Serbia) and of the river Tara canyon (Montenegro) on the other side. It may be assumed that the mild morphological variability of the isolated populations of the Balkan endemic species D. malyana in the canyons and gorges seem to have been affected by the microclimate conditions in their habitats.

ANTHOCYANIN, AGLYCONE AND AGLYCONE-SUGAR CONTENT OF FRUITS OF TEMPERATE NORTH AMERICAN SPECIES OF Gaylussacia (ERICACEAE)

1988 ◽  
Vol 68 (1) ◽  
pp. 247-253 ◽  
Author(s):  
J. R. BALLINGTON ◽  
W. E. BALLINGER ◽  
E. P. MANESS
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
North American ◽  
High Performance ◽  
Hplc Analysis ◽  
Sugar Content ◽  
North American Species ◽  
The Other ◽  
Phylogenetic Implications

HPLC analysis of the true huckleberry species Gaylussacia baccata, G. dumosa, G. frondosa, G. mosieri, and G. ursina identified the 3-monoarabinosides, 3-monogalactosides, and 3-monoglucosides of cyanidin, delphinidin, malvidin, peonidin, and petunidin. Gaylussacia brachycera contained all anthocyanins, except peonidin-3-arabinoside. Gaylussacia brachycera differed from other species in percent delphinidin-3-arabinoside. It was higher than the other species in percent of the aglycone delphinidin and lower in cyanidin, and also higher in percent of the sugar arabinose. There were no detectable differences among the other species for anthocyanins, aglycones, or aglycone-sugars. The phylogenetic implications of the similarities among species of Gaylussacia and Vaccinium in anthocyanins, aglycones, and aglycone-sugars of the fruit were discussed.Key words: High-performance liquid chromatography, huckleberries, blueberries, chemotaxonomy, taxonomy, biosystematics

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