scholarly journals Genesis, Evolution, and Genetic Diversity of the Hexaploid, Narrow Endemic Centaurea tentudaica

Diversity ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 72
Author(s):  
Lucía D. Moreyra ◽  
Francisco Márquez ◽  
Alfonso Susanna ◽  
Núria Garcia-Jacas ◽  
Francisco María Vázquez ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Unknown Origin ◽  
Glacial Maximum ◽  
Niche Modeling ◽  
Interglacial Period ◽  
Environmental Niche ◽  
Last Interglacial ◽  
Environmental Niche Modeling ◽  
Last Interglacial Period ◽  
Close Relationship

Within the genus Centaurea L., polyploidy is very common, and it is believed that, as to all angiosperms, it was key in the history of its diversification and evolution. Centaurea tentudaica is a hexaploid from subsect. Chamaecyanus of unknown origin. In this study, we examined the possible autopolyploid or allopolyploid origin using allozymes and sequences of three molecular markers: nuclear-ribosomic region ETS, and low-copy genes AGT1 and PgiC. We also included three species geographically and morphologically close to C. tentudaica: C. amblensis, C. galianoi, and C. ornata. Neighbor-Net and Bayesian analyses show a close relationship between C. amblensis and C. tentudaica and no relationship to any of the other species, which suggest that C. tentudaica is an autopolyploid of C. amblensis. Allozyme banding pattern also supports the autopolyploidy hypothesis and shows high levels of genetic diversity in the polyploid, which could suggest multiple origins by recurrent crosses of tetraploid and diploid cytotypes of C. amblensis. Environmental niche modeling was used to analyze the distribution of the possible parental species during the present, Last Glacial Maximum (LGM), Last Interglacial Period (LIG), and Penultimate Glacial Maximum (PGM) environmental conditions. Supporting the molecular suggestions that C. tentudaica originated from C. amblensis, environmental niche modeling confirms that past distribution of C. amblensis overlapped with the distribution of C. tentudaica.

scholarly journals Evaluation metrics and validation of presence-only species distribution models based on distributional maps with varying coverage

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kamil Konowalik ◽  
Agata Nosol
Keyword(s):  
Ecological Niche Modeling ◽  
Niche Modeling ◽  
Ecological Niches ◽  
Herbarium Specimens ◽  
Wide Field ◽  
Environmental Niche ◽  
Endemic Plant ◽  
Distribution Models ◽  
Environmental Niche Modeling ◽  
Almost All

AbstractWe examine how different datasets, including georeferenced hardcopy maps of different extents and georeferenced herbarium specimens (spanning the range from 100 to 85,000 km2) influence ecological niche modeling. We check 13 of the available environmental niche modeling algorithms, using 30 metrics to score their validity and evaluate which are useful for the selection of the best model. The validation is made using an independent dataset comprised of presences and absences collected in a range-wide field survey of Carpathian endemic plant Leucanthemum rotundifolium (Compositae). Our analysis of models’ predictive performances indicates that almost all datasets may be used for the construction of a species distributional range. Both very local and very general datasets can produce useful predictions, which may be more detailed than the original ranges. Results also highlight the possibility of using the data from manually georeferenced archival sources in reconstructions aimed at establishing species’ ecological niches. We discuss possible applications of those data and associated problems. For the evaluation of models, we suggest employing AUC, MAE, and Bias. We show an example of how AUC and MAE may be combined to select the model with the best performance.

Variability in surface and deep water conditions in the nordic seas during the last interglacial period

1998 ◽  
Vol 17 (9-10) ◽  
pp. 963-985 ◽  
Author(s):  
Torben Fronval ◽  
Eystein Jansen ◽  
Haflidi Haflidason ◽  
Hans Petter Sejrup
Keyword(s):  
Deep Water ◽  
Interglacial Period ◽  
Last Interglacial ◽  
Nordic Seas ◽  
Last Interglacial Period ◽  
Water Conditions

scholarly journals How warm was Greenland during the last interglacial period?

2016 ◽  
Vol 12 (9) ◽  
pp. 1933-1948 ◽  
Author(s):  
Amaelle Landais ◽  
Valérie Masson-Delmotte ◽  
Emilie Capron ◽  
Petra M. Langebroek ◽  
Pepijn Bakker ◽  
...  
Keyword(s):  
Surface Temperature ◽  
Ice Core ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Water Isotopes ◽  
Interglacial Period ◽  
Last Interglacial ◽  
Last Interglacial Period ◽  
Ice Sheet Topography ◽  
North Greenland

Abstract. The last interglacial period (LIG, ∼ 129–116 thousand years ago) provides the most recent case study of multimillennial polar warming above the preindustrial level and a response of the Greenland and Antarctic ice sheets to this warming, as well as a test bed for climate and ice sheet models. Past changes in Greenland ice sheet thickness and surface temperature during this period were recently derived from the North Greenland Eemian Ice Drilling (NEEM) ice core records, northwest Greenland. The NEEM paradox has emerged from an estimated large local warming above the preindustrial level (7.5 ± 1.8 °C at the deposition site 126 kyr ago without correction for any overall ice sheet altitude changes between the LIG and the preindustrial period) based on water isotopes, together with limited local ice thinning, suggesting more resilience of the real Greenland ice sheet than shown in some ice sheet models. Here, we provide an independent assessment of the average LIG Greenland surface warming using ice core air isotopic composition (δ15N) and relationships between accumulation rate and temperature. The LIG surface temperature at the upstream NEEM deposition site without ice sheet altitude correction is estimated to be warmer by +8.5 ± 2.5 °C compared to the preindustrial period. This temperature estimate is consistent with the 7.5 ± 1.8 °C warming initially determined from NEEM water isotopes but at the upper end of the preindustrial period to LIG temperature difference of +5.2 ± 2.3 °C obtained at the NGRIP (North Greenland Ice Core Project) site by the same method. Climate simulations performed with present-day ice sheet topography lead in general to a warming smaller than reconstructed, but sensitivity tests show that larger amplitudes (up to 5 °C) are produced in response to prescribed changes in sea ice extent and ice sheet topography.

scholarly journals Sediment core fossils in ancient Lake Ohrid: testing for faunal change in molluscs since the Last Interglacial period

2010 ◽  
Vol 7 (3) ◽  
pp. 3969-3999 ◽  
Author(s):  
C. Albrecht ◽  
H. Vogel ◽  
T. Hauffe ◽  
T. Wilke
Keyword(s):  
Sediment Core ◽  
Fossil Record ◽  
Interglacial Period ◽  
Ancient Lake ◽  
Last Interglacial ◽  
Lake Ohrid ◽  
Last Interglacial Period ◽  
History Of ◽  
Extinction Events ◽  
Mollusc Shells

Abstract. Ancient Lake Ohrid is probably of early Pleistocene or Pliocene origin and amongst the few lakes in the world harboring an outstanding degree of endemic biodiversity. Although there is a long history of evolutionary research in Lake Ohrid, particularly on molluscs, a mollusc fossil record has been missing up to date. For the first time, gastropod and bivalve fossils are reported from the basal, calcareous part of a 2.6 m long sediment succession (core Co1200) from the north-eastern part of Lake Ohrid. Electron spin resonance (ESR) dating of mollusc shells from the same stratigraphic level yielded an age of 130±28 ka. Lithofacies III sediments, i.e. a subdivision of the stratigraphic unit comprising the basal succession of core Co1200 between 181.5–263 cm appeared solid, grayish-white, and consisted almost entirely of silt-sized endogenic calcite (CaCO3>70%) and intact and broken mollusc shells. Here we compare the faunal composition of the thanatocoenosis with recent mollusc associations in Lake Ohrid. A total of 13 mollusc species (9 gastropod and 4 bivalve species) could be identified within Lithofacies III sediments. The value of sediment core fossils for reconstructing palaeoenvironmental settings was evaluated. The agreement between sediment and palaeontological proxies was tested. The combined findings of the ecological study and the sediment characteristics suggest deposition in a shallow water environment during the Last Interglacial period. We tested for major faunal changes since the Last Interglacial period and searched for signs of extinction events. The fossil fauna exclusively included species also found in the present fauna, i.e. no extinction events are evident for this site since the Last Interglacial. The thanatocoenosis showed the highest similarity with recent Intermediate Layer (5–25 m) mollusc assemblages. The demonstrated existence of a mollusc fossil record in Lake Ohrid sediment cores also has great significance for future deep drilling projects. It can be hoped that a more far reaching mollusc fossil record will then be obtained, enabling insight into the early evolutionary history of Lake Ohrid.

Advancing into Eternal Silence

2020 ◽  
pp. 571-580
Author(s):  
Hans Blumenberg
Keyword(s):  
Interglacial Period ◽  
Last Interglacial ◽  
Media Archaeology ◽  
Last Interglacial Period ◽  
History Of ◽  
The Relationship

This chapter discusses Hans Blumenberg's essay “Advancing into Eternal Silence: A Century after the Sailing of the Fram” (1993). This essay was written three years before his death. It offers not just the philosophical reading of an episode in the history of polar expeditions ripe with significance, but draws on an anecdote to muse on the relationship between media-archaeology and nihilism. Blumenberg explains that humans are risky beings, and not just because they seek frontier-pushing adventures like the voyage adrift of the Fram. They are risky for the very reason that their biological origins lie in the narrow span of the last interglacial period, when they learned the ability to cope with life caught between the advancing and receding glaciers; the natural being was now pitted against nature.

Assessing the status of critically endangered Kondana soft-furred rat (Millardia kondana) using integrative taxonomy: combining evidence from morphological, molecular and environmental niche modeling

Mammalia ◽  
2020 ◽  
Vol 84 (4) ◽  
pp. 392-406
Author(s):  
Sameer B. Bajaru ◽  
Aparna Lajmi ◽  
Ranjit Manakadan ◽  
Amol R. Kulavmode ◽  
Uma Ramakrishnan
Keyword(s):  
Taxonomic Status ◽  
Niche Modeling ◽  
Critically Endangered ◽  
Morphological Data ◽  
Integrative Approach ◽  
Environmental Niche ◽  
Sister Relationship ◽  
Environmental Niche Modeling ◽  
Precipitation Seasonality ◽  
Significant Difference

AbstractKondana soft-furred rat is a critically endangered (CR) species, known from a single locality – Sinhgad in the northern Western Ghats, India. However, the taxonomic status of this species is uncertain due to its close resemblance to the widely distributed soft-furred field rat Millardia meltada, which has serious implications on the conservation status of Millardia kondana. In this study, we assessed the current taxonomic status of M. kondana through an integrative approach combining morphological, molecular and environmental niche modeling analyses. We collected morphological data from the specimens around Sinhgad as well as preserved specimens in the museum. Both morphological and two-dimensional (2D) morphometrical analyses showed a significant difference between M. kondana and M. meltada. Molecular phylogeny based on cytochrome b gene revealed a sister relationship between M. kondana and M. meltada, and both species form distinct well-supported monophyletic clades. Niche modeling also predicted niche segregation between the two species: M. kondana preferred areas with a high elevation and precipitation seasonality while M. meltada favored regions with a low elevation and precipitation. We confirmed that M. kondana is taxonomically distinct from M. meltada, and based on our estimates of its occurrence and occupancy, M. kondana continues to be treated as CR until further detailed investigations.

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