scholarly journals Evolution and biodiversity of Antarctic organisms: a molecular perspective

2007 ◽  
Vol 362 (1488) ◽  
pp. 2191-2214 ◽  
Author(s):  
Alex David Rogers
Keyword(s):  
Continental Drift ◽  
Population Level ◽  
Extreme Environment ◽  
Morphological Characters ◽  
Secondary Contact ◽  
Genetic Studies ◽  
Antarctic Species ◽  
Taxonomic Groups ◽  
Climatic Cooling ◽  
The Antarctic

The Antarctic biota is highly endemic, and the diversity and abundance of taxonomic groups differ from elsewhere in the world. Such characteristics have resulted from evolution in isolation in an increasingly extreme environment over the last 100 Myr. Studies on Antarctic species represent some of the best examples of natural selection at the molecular, structural and physiological levels. Analyses of molecular genetics data are consistent with the diversity and distribution of marine and terrestrial taxa having been strongly influenced by geological and climatic cooling events over the last 70 Myr. Such events have resulted in vicariance driven by continental drift and thermal isolation of the Antarctic, and in pulses of species range contraction into refugia and subsequent expansion and secondary contact of genetically distinct populations or sister species during cycles of glaciation. Limited habitat availability has played a major role in structuring populations of species both in the past and in the present day. For these reasons, despite the apparent simplicity or homogeneity of Antarctic terrestrial and marine environments, populations of species are often geographically structured into genetically distinct lineages. In some cases, genetic studies have revealed that species defined by morphological characters are complexes of cryptic or sibling species. Climate change will cause changes in the distribution of many Antarctic and sub-Antarctic species through affecting population-level processes such as life history and dispersal.

In situ morphometric study of the Diuris punctata species complex (Orchidaceae), with implications for conservation

2008 ◽  
Vol 21 (4) ◽  
pp. 289 ◽  
Author(s):  
Zoë F. Smith ◽  
Elizabeth A. James ◽  
Cassandra B. McLean
Keyword(s):  
Species Complex ◽  
Flower Colour ◽  
Population Level ◽  
Morphological Characters ◽  
Population Variation ◽  
Morphometric Study ◽  
Herbarium Specimens ◽  
Taxonomic Groups ◽  
Floral Characters

Taxa within the Diuris punctata species complex exhibit high levels of variation at both species and population level. Morphometric data collected in situ were used to investigate species boundaries of four Victorian Diuris species within the Diuris punctata species complex. Morphological characters and taxonomic groups identified in the present study were compared to those described under the current taxonomic treatment. Sixty-five multistate and continuous characters, including seven vegetative and 58 floral characters, were measured in situ across the range of each species within Victoria. The importance of flower colour in distinguishing taxa was highlighted but characters used were generally indiscrete. Certain characters used in current taxonomic descriptions, e.g. floral fragrance, were found to be uninformative. D. fragrantissima was confirmed as a separate taxon within the D. punctata group, justifying its recognition as a unique entity for conservation. Clustering of D. daltonii within D. punctata suggests that the recent elevation of the D. punctata var. daltonii to species level is not justified. The in situ measurement of morphological characters made it possible to incorporate sufficient sampling to encompass intra-specific and intra-population variation and is a feasible method to overcome sampling limitations encountered when herbarium specimens and limited destructive sampling are used.

CharcotianaandAmundsenia, two new genera inTeloschistaceae(lichenized Ascomycota, subfamilyXanthorioideae) hosting two new species from continental Antarctica, andAustroplaca frigida, a new name for a continental Antarctic species

2014 ◽  
Vol 46 (6) ◽  
pp. 763-782 ◽  
Author(s):  
Ulrik SØCHTING ◽  
Isaac GARRIDO-BENAVENT ◽  
Rod SEPPELT ◽  
Miris CASTELLO ◽  
Sergio PÉREZ-ORTEGA ◽  
...  
Keyword(s):  
New Species ◽  
New Genus ◽  
Morphological Characters ◽  
The Arctic ◽  
New Genera ◽  
Antarctic Species ◽  
New Name ◽  
Continental Antarctica ◽  
Two New Species ◽  
The Antarctic

AbstractBased on a combined three locus analysis two new genera,CharcotianaandAmundsenia,are proposed in the lichen familyTeloschistaceae, subfamilyXanthorioideae.Charcotianaincludes the new speciesC. antarctica, which is known only from continental Antarctica. The bipolar genusAmundseniaincludes the new speciesA. austrocontinentalis, which is also known only from continental Antarctica, and the Arctic speciesCaloplaca approximatawhich is here combined into the new genus. The two new genera are phylogenetically distinct, but poor in morphological characters; the new species consist mainly of minute apothecia in cracks of rocks located in the climatically harshest regions of the Antarctic. They are somewhat similar to another continental Antarctic species,Austroplaca frigida,which is described as a new name based on the illegitimate nameCaloplaca frigidaSøchting. The distribution of the four species is mapped.

scholarly journals Relationships among cultivated peas and their wild relatives: Molecular and morphological characterization

2019 ◽  
Vol 48 (4) ◽  
pp. 1011-1019
Author(s):  
Fatih Hanci ◽  
Esra Cebeci
Keyword(s):  
Molecular Study ◽  
Morphological Characters ◽  
Morphological Characterization ◽  
Local Varieties ◽  
Ssr Loci ◽  
Taxonomic Groups ◽  
Clustering Pattern ◽  
Polymorphism Level ◽  
Different Sources ◽  
Simple Sequence

This study was conducted to determine relationship between some wild pea accessions (Pisum fulvum L., P. abyssinicum L., P. sativum var. elatius), local varieties (P. sativum var. sativum L. and P. sativum var. arvense L.) and commercial varieties “Boogie” and “Rondo”. The genetic diversity was evaluated with 14 simple sequence repeat markers and 50 morphological characters. The results of morphology indicated that, genotypes showed a clustering pattern based on the taxonomic groups when considering only flower characters and all morphological characters. During the molecular study, a total of 48 alleles were obtained. Used all primers showed polymorphism in accessions. The number of alleles varied between 2 - 6 among 14 SSR loci revealing the polymorphism level of markers. Similarity coefficient (Dice’s) ranged from 0.100 to 0.800 with an average of 0.378. A dendrogram grouped the 15 genotypes into two main clusters. This information can be utilized for genetic analysis, genotype identification from different sources and development of improved germplasm.

scholarly journals Development of specific markers for the detection of Tolypella canadensis eDNA in water samples

2021 ◽  
Vol 4 ◽  
Author(s):  
Christina Wiebe ◽  
Petra Nowak ◽  
Hendrik Schubert
Keyword(s):  
Rare Species ◽  
Environmental Samples ◽  
Large Scale ◽  
Morphological Characters ◽  
Its2 Region ◽  
Specific Marker ◽  
Specific Primers ◽  
Species Specific ◽  
Taxonomic Groups ◽  
Scale Integration

Assessing the biodiversity of an ecosystem plays a major role in ecosystem management. However, proper determination on species-level is often tricky when morphological features are scarce and especially rare species require huge sampling efforts to be detected in the aquatic realm. As an alternative to conventional methods, environmental samples can be examined via the eDNA method, allowing for large-scale integration as well as taxa resolution independent from expression of morphological characters. However, to apply this technique genetic markers that are specific to a species or at least a genus are required. Such markers until now have been successfully developed only for a few well studied taxonomic groups like, e.g., fishes and amphibians, but are still missing for others, especially plants and algae (e.g. Bista et al. 2017). This project focusses on the development of species-specific markers for the macrophytic green algae Tolypella canadensis (Characeae, Charophyta), a rare alga preferring deep water and known so far mainly from remote places. Tolypella canadensis is a circumpolar species and prefers oligotrophic lakes, where it grows in depths up to 13 m (Langangen 2002; Romanov and Kopyrina 2016). In addition, proper determination of Tolypella-species is a field of a few specialists, further complicating monitoring or even detection of this rare species. The design of the species-specific primers was based on reference nucleotide sequences of the chloroplast genes rbcL, psbC and atpB and of the ribosomal internal transcribed spacer regions ITS1 and ITS2, obtained from GenBank (Perez et al. 2017). To determine the specificity of the newly designed primers, DNA isolates obtained from T. canadensis specimens collected from the Torneträsk (Sweden, 2018) and other charophyte species were prepared in different proportions. The sensitivity of the primers was experimentally assayed by using serial dilutions of T. canadensis DNA. Additionally, a mock test comprised of a sample with the DNA of several charophyte species was conducted and finally, the markers were tested on environmental samples from the Torneträsk. Tolypella canadensis-specific primers of the ITS2 region yielded positive PCR amplifications of one single band when T. canadensis was present in a sample. Cross-amplification was not found during the mock test; other charophyte species did not yield positive amplification. The eDNA samples from the Torneträsk validated the performance of the ITS2 marker. The T. canadensis-specific marker designed in this project was proven to be sensitive and accurate. It could be recommended as a useful tool to detect the presence of T. canadensis DNA, even at low concentration and in complex samples containing other charophyte species.

scholarly journals Introduction. Antarctic ecology: from genes to ecosystems. Part 2. Evolution, diversity and functional ecology

2007 ◽  
Vol 362 (1488) ◽  
pp. 2187-2189 ◽  
Author(s):  
Alex D Rogers ◽  
Eugene J Murphy ◽  
Nadine M Johnston ◽  
Andrew Clarke
Keyword(s):  
Climate Change ◽  
Life Histories ◽  
Natural Populations ◽  
Environmental Parameters ◽  
Functional Ecology ◽  
Antarctic Species ◽  
Trade Offs ◽  
Genes To Ecosystems ◽  
Micro Organisms ◽  
The Antarctic

The Antarctic biota has evolved over the last 100 million years in increasingly isolated and cold conditions. As a result, Antarctic species, from micro-organisms to vertebrates, have adapted to life at extremely low temperatures, including changes in the genome, physiology and ecological traits such as life history. Coupled with cycles of glaciation that have promoted speciation in the Antarctic, this has led to a unique biota in terms of biogeography, patterns of species distribution and endemism. Specialization in the Antarctic biota has led to trade-offs in many ecologically important functions and Antarctic species may have a limited capacity to adapt to present climate change. These include the direct effects of changes in environmental parameters and indirect effects of increased competition and predation resulting from altered life histories of Antarctic species and the impacts of invasive species. Ultimately, climate change may alter the responses of Antarctic ecosystems to harvesting from humans. The unique adaptations of Antarctic species mean that they provide unique models of molecular evolution in natural populations. The simplicity of Antarctic communities, especially from terrestrial systems, makes them ideal to investigate the ecological implications of climate change, which are difficult to identify in more complex systems.

Inheritance of three marker characters in Medicago truncatula Gaertn. (M. tribuloides Desr.)

1965 ◽  
Vol 16 (1) ◽  
pp. 31 ◽  
Author(s):  
JP Simon
Keyword(s):  
Medicago Truncatula ◽  
Recessive Gene ◽  
Morphological Characters ◽  
Anthocyanin Pigmentation ◽  
Genetic Studies ◽  
Seed Certification ◽  
Pigmentation Pattern ◽  
Barrel Medic ◽  
Complete Penetrance ◽  
Dominant Genes

The inheritance has been studied of three morphological characters which could be used as markers in the "pure seed" certification of commercial varieties of barrel medic, M. truncatula Gaertn. The leaf anthocyanin pigmentation pattern, as found in accession No. 2829, and the clockwise form of pod coiling characterizing accession No. 3309, are determined by single dominant genes. The spineless character of the pod of accession No. 2822 is due to a recessive gene. The simple inheritance of these characters and the complete penetrance of the genes concerned indicate that the anthocyanin marker and the spineless pod could be used for certification. Since the clockwise-anticlockwise pattern of coiling occurs in both forms in commercial barrel medic varieties, it is likely to be useful only as a marker in genetic studies. Details are given of a satisfactory procedure developed for crossing medic varieties

scholarly journals Phylogeny of the Eocene Antarctic Tapetinae Gray, 1851 (Bivalvia, Veneridae) from the La Meseta and Submeseta formations

2020 ◽  
Vol 94 (5) ◽  
pp. 799-818
Author(s):  
Maximiliano Jorge Alvarez ◽  
Claudia Julia del Río
Keyword(s):  
Phylogenetic Analysis ◽  
New Species ◽  
New Genus ◽  
Late Eocene ◽  
New Combination ◽  
New Genera ◽  
Systematic Analysis ◽  
Antarctic Species ◽  
The Antarctic ◽  
First Time

AbstractSystematic analysis shows that the Southern Hemisphere bivalve genus Retrotapes includes the Antarctic species R. antarcticus, R. newtoni, and R. robustus and recognizes for the first time the presence of Katelysia represented by K. florentinoi. Two new genera were erected in this study: Marciachlys new genus to include M. inflata new combination, and Adelfia new genus, which includes A. austrolissa new combination and A. omega new species from the Eocene of Antarctica, and the late Eocene Chilean A. arenosa new combination. Eurhomalea carlosi was synonymized with K. florentinoi; Cyclorismina marwicki with R. antarcticus; Gomphina iheringi was considered an indeterminate species; and Cockburnia lunulifera was excluded from the Tapetinae. These systematic assignments are supported by a phylogenetic analysis, which recognizes an Austral clade of Tapetinae, comprising all the genera mentioned above, along with Marcia, Paleomarcia, Atamarcia, and Protapes.UUID: http://zoobank.org/a8c91a9f-99ec-4235-8416-d398771a3eb2

scholarly journals Phylotypic Characterization of Mycobionts and Photobionts of Rock Tripe Lichen in East Antarctica

2019 ◽  
Vol 7 (7) ◽  
pp. 203 ◽  
Author(s):  
Merry Sailonga Faluaburu ◽  
Ryosuke Nakai ◽  
Satoshi Imura ◽  
Takeshi Naganuma
Keyword(s):  
Green Algae ◽  
Phenotypic Variability ◽  
Antarctic Species ◽  
Green Algal ◽  
The Common ◽  
Valley Site ◽  
The Antarctic ◽  
Specially Protected Areas ◽  
High Diversity

Saxicolous rock ripe lichens that grow on rocks in the East Antarctic fellfields were sampled for phylotypic characterization of its constituent mycobionts (fungi) and photobionts (algae and cyanobacteria). The rock tripe lichen-forming fungal and algal phylotypes were classified under the common lichen-forming genera of ascomycetes, namely, Umbilicaria, and green algae, namely, Trebouxia and Coccomyxa. However, phylotypes of the green algal chloroplasts and the lichen-associated cyanobacteria showed unexpectedly high diversity. The detected chloroplast phylotypes were not fully affiliated with the green algal genera Trebouxia or Coccomyxa. The predominant chloroplast phylotype demonstrated maximum resemblance to Neglectella solitaria, which is neither a known Antarctic species nor a typical lichen photobiont. Another dominant chloroplast phylotype belonged to the atypical Antarctic green algae family. Cyanobacterial phylotypes were dominated by those affiliated with the Microcoleus species rather than the well-known lichen-associates, Nostoc species. The occurrences of these Microcoleus-affiliated cyanobacterial phylotypes were specifically abundant within the Yukidori Valley site, one of the Antarctic Specially Protected Areas (ASPA). The ASPA site, along with another 50 km-distant site, yielded most of the cryptic diversity in the phylotypes of chloroplasts and cyanobacteria, which may contribute to the phenotypic variability within the rock tripe lichen photobionts.

Zoogeography of the Antarctic ascidian fauna in relation to the sub-Antarctic and South America

2007 ◽  
Vol 19 (3) ◽  
pp. 321-336 ◽  
Author(s):  
Carmen Primo ◽  
Elsa Vázquez
Keyword(s):  
South America ◽  
Saint Paul ◽  
South American ◽  
South American Species ◽  
Species Classification ◽  
Antarctic Region ◽  
Antarctic Species ◽  
Tristan Da Cunha ◽  
Centre Of Origin ◽  
The Antarctic

AbstractThis study of the relationships between the Antarctic, sub-Antarctic and South America biogeographical regions used both existing and new data. We constructed a presence/absence matrix of 237 species for 27 biogeographical divisions which included the Amsterdam-Saint Paul and Tristan da Cunha islands. Species and areas were classified using cluster analysis combined with MDS ordination. Six main groups were obtained from the species classification: 1) Amsterdam-Saint Paul, and 2) Tristan da Cunha species, 3) species from the Macquarie Province, 4) species from the sub-Antarctic Region, 5) Antarctic species and species distributed in the cold regions, 6) South American species. The biogeographical components were dominated by the endemic (although it is not as high as in other groups), Antarctic-South America and Southern Hemisphere elements. Except for Amsterdam-Saint Paul, Tristan da Cunha and Bouvet, the areas considered were grouped together with Macquarie being rather related to New Zealand regions. We speculate that the Antarctic Region may have acted as an “evolutionary incubator”, providing a centre of origin for sub-Antarctic and South American ascidians.

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