Search results for "evolutionary"
showing 10 items of 4392 documents
Adaptation to fluctuations in temperature by nine species of bacteria
2018
Rapid environmental fluctuations are ubiquitous in the wild, yet majority of experimental studies mostly consider effects of slow fluctuations on organism. To test the evolutionary consequences of fast fluctuations, we conducted nine independent experimental evolution experiments with bacteria. Experimental conditions were same for all species, and we allowed them to evolve either in fluctuating temperature alternating rapidly between 20°C and 40°C or at constant 30°C temperature. After experimental evolution, we tested the performance of the clones in both rapid fluctuation and in constant environments (20°C, 30°C and 40°C). Results from experiments on these nine species were combined meta…
Genome-wide analyses reveal population structure and identify candidate genes associated with tail fatness in local sheep from a semi-arid area.
2021
Abstract Under a climate change perspective, the genetic make-up of local livestock breeds showing adaptive traits should be explored and preserved as a priority. We used genotype data from the ovine 50 k Illumina BeadChip for assessing breed autozygosity based on runs of homozygosity (ROH) and fine-scale genetic structure and for detecting genomic regions under selection in 63 Tunisian sheep samples. The average genomic inbreeding coefficients based on ROH were estimated at 0.017, 0.021, and 0.024 for Barbarine (BAR, n = 26), Noire de Thibar (NDT, n = 23), and Queue fine de l'Ouest (QFO, n = 14) breeds, respectively. The genomic relationships among individuals based on identity by state (I…
Vegetation Diversity of Screes and Taluses of The Pamir and South-Western Tian Shan in Middle Asia
2021
AbstractThis paper presents the results of phytosociological research on scree vegetation of the Pamir and south-western Tian Shan. We collected 222 phytosociological relevés during field studies conducted in 2015–2019, applying the Braun-Blanquet approach. We identified 21 plant communities on mobile and stabilized screes of colluvial cones, aprons and fans, inhabiting mainly the montane and alpine belts in several ranges (e.g. Peter the First, Alichur, Shugnan, Shachdarian, Darvaz, Rushan, Vanch, Fergana, Kyrgyz and Terskey ranges). As a result we provide the first comprehensive hierarchical syntaxonomic synopsis of scree communities at montane and alpine elevations in the eastern Middle …
Red List of vascular plants of Tajikistan – the core area of the Mountains of Central Asia global biodiversity hotspot
2020
AbstractCentral Pamir-Alai, which is located almost entirely within the area of Tajikistan, is one of the world hotspots of biodiversity, harbouring ca. 4,300 species and 1,400 endemic plants. The first application of the IUCN Red List criteria reveals that among all native species occurring in Tajikistan 1,627 taxa (38.11%) are threatened, including 23 extinct (0.54%), 271 (6.34%) critically endangered (CR), 717 (16.79%) endangered (EN) and 639 (14.96%) vulnerable (VU). Globally, 20 taxa are extinct, 711 (16.65%) threatened, including 144 (3.37%) critically endangered, 322 (7.54%) endangered and 245 (5.73%) vulnerable. As we found positive correlation between human density and the number o…
Dinosaur bonebed amber from an original swamp forest soil
2021
AbstractDinosaur bonebeds with amber content, yet scarce, offer a superior wealth and quality of data on ancient terrestrial ecosystems. However, the preserved palaeodiversity and/or taphonomic characteristics of these exceptional localities had hitherto limited their palaeobiological potential. Here we describe the amber from the Lower Cretaceous dinosaur bonebed of Ariño (Teruel, Spain) using a multidisciplinary approach. Amber is found in both a root layer with amber strictly in situ and a litter layer namely composed of aerial pieces unusually rich in bioinclusions, encompassing 11 insect orders, arachnids, and a few plant and vertebrate remains, including a feather. Additional palaeont…
TRIBUTE TO JORDI MARIA DE GIBERT ATIENZA
2020
On September 23rd 2012, Jordi Maria de Gibert Atienza, an innovative explorer of the fossil record, passed away suddenly in Barcelona. He left behind interesting scientifi c contributions in the areas of invertebrate ecology, palaeoecology, evolutionary ecology, taphonomy and ichnology. Jordi Maria was only 44 and had a whole life in science ahead of him. The 2014 volume of the Spanish Journal of Palaeontology is dedicated to his memory.
Targeted NGS for species level phylogenomics: “made to measure” or “one size fits all”?
2017
Targeted high-throughput sequencing using hybrid-enrichment offers a promising source of data for inferring multiple, meaningfully resolved, independent gene trees suitable to address challenging phylogenetic problems in species complexes and rapid radiations. The targets in question can either be adopted directly from more or less universal tools, or custom made for particular clades at considerably greater effort. We applied custom made scripts to select sets of homologous sequence markers from transcriptome and WGS data for use in the flowering plant genus Erica (Ericaceae). We compared the resulting targets to those that would be selected both using different available tools (Hyb-Seq; M…
Obruchevacanthus ireneae gen. et sp. nov., a new ischnacanthiform (Acanthodii) from the Lower Devonian of Spain
2014
New disarticulated material of typically ischnacanthid scales, tooth whorls, and ?dentigerous jaw bones that occur recurrently together at many levels of the Lower Devonian of the Iberian Chain (Spain) is described. Based on their stratigraphical occurrence, histological evidence and comparison with similar ischnacanthid assemblages from other localities, we suggest including all of these remains in a unique natural assemblage, Obruchevacanthus ireneae gen. et sp. nov. This new taxon shares some features with Trundlelepis cervicostulata from the Lower Devonian of New South Wales (Australia), as for example the presence of a poorly developed pore canal system in their scales. This feature su…
The complex nature of progenetic species — examples from Mesozoic ammonites
1991
Several examples of progenetic species among Mesozoic ammonites are investigated. The ammonites are Middle Jurassic kosmoceratids, Upper Jurassic oppeliids, and Upper Cretaceous scaphites. As assessed through outgroup comparison, the progenetic species in each of these examples is characterized by small size at maturity and the presence of morphological features typical of those of the juveniles of more primitive species. However, in none of these examples is the progenetic species a duplicate form of the juvenile stage of more primitive species. There are at least three kinds of features of progenetic species that differ from those of the juveniles of more primitive species: (1) symplesiom…
The proliferative ventricular zone in adult vertebrates: a comparative study using reptiles, birds, and mammals
2002
Although evidence accumulated during the last decades has advanced our understanding of adult neurogenesis in the vertebrate brain, many aspects of this intriguing phenomenon remain controversial. Here we review the organization and cellular composition of the ventricular wall of reptiles, birds, and mammals in an effort to identify differences and commonalities among these vertebrate classes. Three major cell types have been identified in the ventricular zone of reptiles and birds: migrating (Type A) cells, radial glial (Type B) cells, and ependymal (Type E) cells. Cells similar anatomically and functionally to Types A, B, and E have also been described in the ventricular wall of mammals, …