scholarly journals British phenological records indicate high diversity and extinction rates among late-summer-flying pollinators

2018 ◽  
Vol 222 ◽  
pp. 278-283 ◽  
Author(s):  
Nicholas J. Balfour ◽  
Jeff Ollerton ◽  
Maria Clara Castellanos ◽  
Francis L.W. Ratnieks
2000 ◽  
Vol 69 (4) ◽  
pp. 213-222 ◽  
Author(s):  
J. John Sepkoski

Approximately 2,600 genera of marine crustaceans have been recognized in the fossil record, and crustaceans constitute the major component of marine arthropod diversity from the mid- Paleozoic to the Recent. Despite problems of sporadic fossil preservation and/or taxonomic ambiguity, some general statements can be made about the history of crustacean biodiversity, based on global taxonomic data bases. Ostracodes were the first major group to radiate, attaining high diversity during the Ordovician Period with other members of the Paleozoic evolutionary fauna; rates of extinction and responses to mass extinctions were also similar to those of groups within the Paleozoic fauna. Malacostracans and barnacles (cirripedes), the two other crustacean groups with important fossil records, had minor diversity throughout the Paleozoic Era. Both groups experienced diversification from the mid-Mesozoic to Recent with lower extinction rates, as characteristic members of the Modern evolutionary fauna.


Author(s):  
Karen J. Esler ◽  
Anna L. Jacobsen ◽  
R. Brandon Pratt

As mediterranean-type climate (MTC) regions emerged and expanded, species from the regional pool colonized and persisted in these new climate regions. In general, taxa were derived from a few types of historical ‘geoflora’ communities: temperate forest, subtropical and tropical, and semi-arid or arid. Some of the taxa within modern mediterranean-type vegetation represent relatively ancient relict taxa that pre-date the emergence of mediterranean-type drivers. Other lineages underwent subsequent speciation, resulting in the evolution of new MTC region-specific taxa, including the production of many new species through evolutionary radiations. Low extinction rates associated with historically stable climate and limited recent geological activity might explain the high diversity found in some MTC regions, while in regions with more topographical variation the ability of species to move across elevation gradients has been suggested also to have allowed species to be buffered from climatic changes that may otherwise have led to extinctions.


2017 ◽  
Author(s):  
Jacob B. Socolar ◽  
Alexander C. Lees

ABSTRACTGeographic gradients in species richness, including latitudinal gradients, can arise from geographic variation in any of three mechanisms: the geologic age of habitats, net rates of evolutionary diversification, or rates of sympatry among diversifying lineages. Here we show that variation in rates of sympatry is a dominant force structuring geographic richness gradients in birds. Species-rich sites contain disproportionately high numbers of recently diverged sympatric species but contain lineages with slower-than-average diversification rates. The positive sympatry-diversity relationship consistently overwhelms the negative diversification-diversity relationship, particularly among high-diversity sites (>250 species). These patterns repeat across biomes and continents with striking regularity, and remain consistent across multiple timescales, including the recent evolutionary past. Biogeographic and evolutionary patterns in birds are consistent with a role for ecological conditions in promoting species coexistence, which allows sister species to co-occur and potentially lowers extinction rates.


2006 ◽  
Vol 36 (17) ◽  
pp. 12
Author(s):  
MICHAEL E. PICHICHERO
Keyword(s):  

2020 ◽  
Vol 643 ◽  
pp. 197-217 ◽  
Author(s):  
SME Fortune ◽  
SH Ferguson ◽  
AW Trites ◽  
B LeBlanc ◽  
V LeMay ◽  
...  

Climate change may affect the foraging success of bowhead whales Balaena mysticetus by altering the diversity and abundance of zooplankton species available as food. However, assessing climate-induced impacts first requires documenting feeding conditions under current environmental conditions. We collected seasonal movement and dive-behaviour data from 25 Eastern Canada-West Greenland bowheads instrumented with time-depth telemetry tags and used state-space models to examine whale movements and dive behaviours. Zooplankton samples were also collected in Cumberland Sound (CS) to determine species composition and biomass. We found that CS was used seasonally by 14 of the 25 tagged whales. Area-restricted movement was the dominant behaviour in CS, suggesting that the tagged whales allocated considerable time to feeding. Prey sampling data suggested that bowheads were exploiting energy-rich Arctic copepods such as Calanus glacialis and C. hyperboreus during summer. Dive behaviour changed seasonally in CS. Most notably, probable feeding dives were substantially shallower during spring and summer compared to fall and winter. These seasonal changes in dive depths likely reflect changes in the vertical distribution of calanoid copepods, which are known to suspend development and overwinter at depth during fall and winter when availability of their phytoplankton prey is presumed to be lower. Overall, CS appears to be an important year-round foraging habitat for bowheads, but is particularly important during the late summer and fall. Whether CS will remain a reliable feeding area for bowhead whales under climate change is not yet known.


2010 ◽  
Vol 17 (1) ◽  
pp. 17-30 ◽  
Author(s):  
Katarzyna J. Chwedorzewska

ABSTRACTThe geographic position, astronomic factors (e.g. the Earth’s maximum distance from the Sun during winter), ice cover and altitude are the main factors affecting the climate of the Antarctic, which is the coldest place on Earth. Parts of Antarctica are facing the most rapid rates of anthropogenic climate change currently seen on the planet. Climate changes are occurring throughout Antarctica, affecting three major groups of environmental variables of considerable biological significance: temperature, water, UV-B radiation.Low diversity ecosystems are expected to be more vulnerable to global changes than high diversity ecosystems


Author(s):  
Majid Baserisalehi ◽  
Samira Zarezadeh ◽  
Majid Baserisalehi ◽  
Saeed Shoa

Stenotrophomonas maltophilia is an emerging pathogenic non-fermentative Gram-negative Bacillus species. It has caused many nosocomial infections and can be isolated from various hospital wards and healthcare facilities. Research has shown that most of its strains are inherently resistant to many antibiotics and have multidrug resistance. This research intended to determine its occurrence frequency at some Hospitals in shiraz, Iran. The present study was conducted in six months (from early spring to late summer 2019). Clinical samples (Blood, Urine and cerebrospinal fluid (CSF)) collected from 120 patients afflicted with various infections. The samples were transferred to the Laboratory and subjected to microbiological analysis. Identification of the isolates was carried out by phenotypic methods and Stenotrophomonas maltophilia isolates verified using molecular methods. In total, various bacteria were isolated from 84 clinical samples. The isolates were Escherichia coli, Enterobacter aerogenes, Klebsiella pneumoniae, Stenotrophomonas maltophilia, Staphylococcus aureus and Pseudomonas aeruginosa. Stenotrophomonas maltophilia was isolated from 17 (20.2%) positive samples and most of them were isolated from blood samples. Our finding indicated that Stenotrophomonas maltophilia isolated more from blood samples follow by CSF sample. In addition, our finding illustrated that Stenotrophomonas maltophilia can be considered as the common nosocomial agent at hospitals in Shiraz, Iran.


2019 ◽  
Vol 2019/2 ◽  
pp. 41-64
Author(s):  
S. C. ROWELL

CONCUBINE AND ENCHANTRESS: KATARZYNA TELNICZANKA AND HER BLACK MYTH Summary S.C. R O W E L L Katarzyna Hochstadt of Telnicz (ca 1480–1528), mistress of Sigismund the Old, mother of John of the Lithuanian Dukes, bishop of Vilnius (1519–36) and Poznań (1536–38) has come down in history as an enchanting beauty or a witch, or both. Her image is defined by her relationship with powerful men – her lover, her son, her husband (Andrzej Kościelecki, castellan of Wojnicz and sub–treasurer of the Crown of Poland) and alleged victims (various royal secretaries and high–ranking clerics). This article assesses what little by way of solid evidence is known of her life and how this can be related with the image of man–chasing vamp, interference in the running of the diocese of Vilnius (thereby allegedly provoking the appointment of bishop protectors to the see) and scandal in village and town (according to one seventeenth–century historian). There is evidence that while John of the Lithuanian Dukes was still a minor and enjoyed the rank of provost of Płock and Poznań and canon of Kraków the property associated with his office was overseen by his step–father and perhaps by his mother. After John became bishop of Vilnius, Her Magnificence the Bishop‘s Mother, the Lady Dowager Castellan of Wojnicz and Sub–Treasurer of the Crown of Poland resided for some time at her son‘s court in Vilnius and on at least two occasions exercised her maternal influence to facilitate access to the bishop for canons (Stanislaw Dambrowka, Martin of Dusniki and Albert Wielezinski) involved in a dispute with their brother canon and scholast Jakub Staszkowski. The detailed discussion of internal cathedral disputes in the presence of a lay person, and even worse, a woman, scandalised members of the Cathedral Chapter but there is no evidence that Lady Katarzyna sought to determine the outcome of this case. We also know that she patronised at least one noblewoman (the widowed sister–in–law of Bishop Albert Tabor) who subsequently adopted Bishop John as her son and heir and made financial endowments on both the bishop and his mother. After Katarzyna died in Vilnius in the late summer of 1528 her corpse was transported to Kraków for burial by a Vilnius canon, Erasmus Eustachii, whose family had connections with Andrzej Kościelecki and Bishop John of Vilnius. The satirical verse penned by Andrzej Krzycki concerning a mother–stepmother and father–stepfather (Katarzyna and King Sigismund) and „an old hag who stinks like a goat“ represents neo–Latin literary exercises provoked by fear of the influence at the royal court of Katarzyna and her family rather than an accurate and literal description of Katarzyna and her activities.


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