Social dominance and habitat utilization in Antechinus stuartii (Marsupialia)

1979 ◽  
Vol 27 (4) ◽  
pp. 517 ◽  
Author(s):  
RW Braithwaite
Keyword(s):  
Social Dominance ◽  
Food Resource ◽  
Winter Mortality ◽  
Mating Season ◽  
Resource Base ◽  
Observation Cage ◽  
Antechinus Stuartii ◽  
History Of ◽  
Selection For ◽  
Male Reproductive Effort

A trapping study of Antechinus stuartii was conducted in subtropical rain forest in 1971-72. Juveniles were communal during the period of abundant food and became solitary in autumn when food diminished. Dyad testing in a field observation cage permitted analysis of social dominance in males. Dominant males had individual ranges in habitats where resources permitted rapid growth throughout winter, whereas subordinate males, in poorer habitat, grew slowly. As winter mortality was low, the advantage of this superior food resource base may lie during the mating season, the more energetic dominant males being able to mate with more females. The probability of contribution to the gene pool by subordinate males appears low. Selection for high male reproductive effort is intensified by the brief annual mating season in this monoestrous species. The life history of this species appears to be geared to predictable seasonal food resources, but it may not be optimal throughout the present range, and the species appears to be evolutionarily trapped.

CORRELATED RESPONSE IN BROWN SARSON

1970 ◽  
Vol 12 (4) ◽  
pp. 905-913 ◽  
Author(s):  
T. Swamy Rao
Keyword(s):  
Gamma Irradiation ◽  
Seed Set ◽  
Previous History ◽  
The Self ◽  
Correlated Response ◽  
History Of ◽  
Self Compatibility ◽  
Selection For ◽  
Direction Opposite ◽  
Brown Sarson

The correlated response with changes in self-compatibility in three varieties of brown sarson subjected to gamma irradiation was examined. Selection for improved seed set in the irradiated populations showed that substantial correlated response can result for a constellation of other characters in which the self-compatible and self-incompatible forms differ. The correlated response was in a direction opposite to that of the previous history of selection.

Le fonti, i metodi e le narrazioni della storia della videoarte in Italia negli anni Settanta

2017 ◽  
Vol 2 (1) ◽  
Author(s):  
Lisa Parola
Keyword(s):  
Comparative Study ◽  
Contemporary Art ◽  
Narrative Structure ◽  
Video Art ◽  
Wide Range ◽  
History Of ◽  
Selection For ◽  
The Many ◽  
Art And Architecture ◽  
Selection Of

This essay derives from the primary need to make order between direct and indirect sources available for the reconstruction of the history of video art in Italy in the seventies. In fact, during the researches for the Ph.D. thesis it became clear that in most cases it is difficult to define, in terms of facts, which of the different historiographies should be taken into consideration to deepen the study of video art in Italy. Beyond legitimate differences of perspectives and methods, historiographical narratives all share similar issues and narrative structure. The first intention of the essay is, therefore, to compare the different historiographic narratives on Italian video art of the seventies, verifying their genealogy, the sources used and the accuracy of the narrated facts. For the selection of the corpus, it was decided to analyze in particular monographic volumes dealing with the history of the origins of video art in Italy. The aim was, in fact, to get a wide range of types of "narrations", as in the case of contemporary art and architecture magazines, which are examined in the second part of the essay. After the selection, for an analytical and comparative study of the various historiography, the essay focuses only on the Terza Biennale Internazionale della Giovane Pittura. Gennaio ’70. Comportamenti, oggetti e mediazioni (Third International Biennial of Young Painting. January '70. Behaviors, Objects and Mediations, 1970, Bologna), the exhibition which - after Lucio Fontana's pioneering experiments - is said to be the first sign of the arrival of videotape in Italy (called at the time videorecording), curated by Renato Barilli, Tommaso Trini, Andrea Emiliani and Maurizio Calvesi. The narration given so far of this exhibition appeared more mythological than historical and could be compared structurally to that of the many numerous beginnings that historiographyies on international video art identify as ‘first’ and ‘generative’. In the first part of the essay the 'facts' related to Gennaio ’70, as narrated by historiography on video art, are compared. In the second part the survey is carried out through some of the direct sources identified during the research, with the aim of answering to questions raised by the comparison between historiographies. Concluding, it is important to underline that the tapes containing the videos transmitted have not been found and seem to have disappeared since the ending of the exhibition. Nevertheless, the deepening of the works and documentation transmitted during the exhibition is possible thanks to other types of sources which give us many valuable information regarding video techniques and practices at the beginning of 1970 in Italy.

scholarly journals Selection for increased tibia length in mice alters skull shape through parallel changes in developmental mechanisms

2020 ◽  
Author(s):  
Colton M. Unger ◽  
Jay Devine ◽  
Benedikt Hallgrímsson ◽  
Campbell Rolian
Keyword(s):  
Endochondral Ossification ◽  
Morphological Changes ◽  
Cranial Base ◽  
Direct Selection ◽  
Micro Ct ◽  
Growth Plates ◽  
History Of ◽  
Selection For ◽  
Tibia Length ◽  
Shape Changes

AbstractBones in the vertebrate cranial base and limb skeleton grow by endochondral ossification, under the control of growth plates. Mechanisms of endochondral ossification are conserved across growth plates, which increases covariation in size and shape among bones, and in turn may lead to correlated changes in skeletal traits not under direct selection. We used micro-CT and geometric morphometrics to characterize shape changes in the cranium of the Longshanks mouse, which was selectively bred for longer tibiae. We show that Longshanks skulls became longer, flatter, and narrower in a stepwise process. Moreover, we show that these morphological changes likely resulted from developmental changes in the growth plates of the Longshanks cranial base, mirroring changes observed in its tibia. Thus, indirect and non-adaptive morphological changes can occur due to developmental overlap among distant skeletal elements, with important implications for interpreting the evolutionary history of vertebrate skeletal form.

scholarly journals Preference for hierarchy is associated with reduced empathy and increased counter-empathy towards others, especially out-group targets

2019 ◽  
Author(s):  
Sa-kiera Tiarra Jolynn Hudson ◽  
Mina Cikara ◽  
Jim Sidanius
Keyword(s):  
Social Dominance ◽  
Group Membership ◽  
Social Dominance Orientation ◽  
Group Setting ◽  
Group Boundaries ◽  
The World ◽  
History Of ◽  
Group Members ◽  
Prejudicial Attitudes ◽  
Status Differences

The capacity to empathize with others facilitates prosocial behavior. People’s willingness and capacity to empathize, however, is often contingent upon the target’s group membership – people are less empathic towards those they categorize as out-group members. In competitive or threatening intergroup contexts, people may even feel pleasure (counter-empathy) in response to out-group members’ misfortunes. Social dominance orientation (SDO), or the extent to which people prefer and promote group-based inequalities, is an ideological variable that is associated with a competitive view of the world, increased prejudicial attitudes, and decreased empathy. Thus, higher levels of SDO should be associated with reduced empathy and increased counter-empathy in general, but especially towards those whose subjugation maintains group inequalities. Across three studies we show that among White individuals, higher SDO levels are associated with less empathy, and more counter-empathy in response to others’ good and bad fortunes. More importantly, these reductions in empathy and increases in schadenfreude as a function of SDO were significantly stronger for Asian and Black targets than for in-group White targets when group boundaries were made salient prior to the empathy ratings. Finally, in a fourth study we show that this phenomenon is not dependent upon a history of status differences: higher SDO scores were associated with decreased empathy and increased counter-empathy for competitive out-group (relative to in-group) targets in a novel group setting. We discuss implications of these effects for hierarchy maintenance.

scholarly journals Transitional genomes and nutritional role reversals identified for dual symbionts of adelgids (Aphidoidea: Adelgidae)

2021 ◽  
Author(s):  
Dustin T. Dial ◽  
Kathryn M. Weglarz ◽  
Akintunde O. Aremu ◽  
Nathan P. Havill ◽  
Taylor A. Pearson ◽  
...  
Keyword(s):  
Evolutionary History ◽  
Life Cycles ◽  
Fluctuating Selection ◽  
Complex Life Cycles ◽  
History Of ◽  
Sap Feeding ◽  
Selection For ◽  
Gains And Losses ◽  
Conifer Trees ◽  
Plant Sap

AbstractMany plant-sap-feeding insects have maintained a single, obligate, nutritional symbiont over the long history of their lineage. This senior symbiont may be joined by one or more junior symbionts that compensate for gaps in function incurred through genome-degradative forces. Adelgids are sap-sucking insects that feed solely on conifer trees and follow complex life cycles in which the diet fluctuates in nutrient levels. Adelgids are unusual in that both senior and junior symbionts appear to have been replaced repeatedly over their evolutionary history. Genomes can provide clues to understanding symbiont replacements, but only the dual symbionts of hemlock adelgids have been examined thus far. Here, we sequence and compare genomes of four additional dual-symbiont pairs in adelgids. We show that these symbionts are nutritional partners originating from diverse bacterial lineages and exhibiting wide variation in general genome characteristics. Although dual symbionts cooperate to produce nutrients, the balance of contributions varies widely across pairs, and total genome contents reflect a range of ages and degrees of degradation. Most symbionts appear to be in transitional states of genome reduction. Our findings support a hypothesis of periodic symbiont turnover driven by fluctuating selection for nutritional provisioning related to gains and losses of complex life cycles in their hosts.

scholarly journals Mobulid rays feed on euphausiids in the Bohol Sea

2017 ◽  
Vol 4 (5) ◽  
pp. 161060 ◽  
Author(s):  
Christoph A. Rohner ◽  
Katherine B. Burgess ◽  
Joshua M. Rambahiniarison ◽  
Joshua D. Stewart ◽  
Alessandro Ponzo ◽  
...  
Keyword(s):  
Life History ◽  
Food Resource ◽  
Stomach Contents ◽  
Fishing Effort ◽  
Fishing Activity ◽  
Prey Preferences ◽  
Manta Birostris ◽  
History Of ◽  
By Catch ◽  
Mobula Japanica

Mobulid rays have a conservative life history and are caught in direct fisheries and as by-catch. Their subsequent vulnerability to overexploitation has recently been recognized, but fisheries management can be ineffective if it ignores habitat and prey preferences and other trophic interactions of the target species. Here, we assessed the feeding ecology of four mobulids ( Manta birostris , Mobula tarapacana , M. japanica , M. thurstoni ) in the Bohol Sea, Philippines, using stomach contents analysis of fisheries specimens landed between November and May in 2013–2015. We show that the mobulids feed heavily on euphausiid krill while they are in the area for approximately six months of the year. We found almost no trophic separation among the mobulid species, with Euphausia diomedeae as the major prey item for all species, recorded in 81 of 89 total stomachs (91%). Mobula japanica and M. thurstoni almost exclusively had this krill in their stomach, while M. tarapacana had a squid and fish, and Ma. birostris had myctophid fishes and copepods in their stomachs in addition to E. diomedeae . This krill was larger than prey for other planktivorous elasmobranchs elsewhere and contributed a mean of 61 364 kcal per stomach (±105 032 kcal s.e., range = 0–631 167 kcal). Our results show that vertically migrating mesopelagic species can be an important food resource for large filter feeders living in tropical seas with oligotrophic surface waters. Given the conservative life history of mobulid rays, the identification of common foraging grounds that overlap with fishing activity could be used to inform future fishing effort.

The Relationship Between Cinnamon Fungus (Phytophthora Cinnamomi) and the Abundance of Antechinus Stuartii (Dasyuridae: Marsupialia) in the Brisbane Ranges, Victoria.

1993 ◽  
Vol 20 (2) ◽  
pp. 251 ◽  
Author(s):  
GR Newell ◽  
BA Wilson
Keyword(s):  
Small Mammal ◽  
National Park ◽  
Phytophthora Cinnamomi ◽  
Capture Rate ◽  
Ground Level ◽  
Structural Level ◽  
Public Land Management ◽  
Water Board ◽  
Antechinus Stuartii ◽  
History Of

The Brisbane Ranges include areas of National Park, water catchment and freehold land that have a history of infection with the pathogen P. cinnamomi since the late 1960s. A systematic survey of the small-mammal fauna of the Brisbane Ranges National Park and the Geelong and District Water Board catchments in relation to the pathogen was carried out in 1987. A. stuartii was the only species trapped regularly. The volume of vegetation to a structural level of 60 cm was significantly lower at sites where P. cinnamomi was present. The abundance of A. stuartii was also significantly lower at sites infected with P. cinnamomi, and a significant relationship is shown between the capture rate of A. stuartii and the volume of vegetation present up to 40 cm above ground level. This work indicates a possible association between P. cinnamomi and populations of A. stuartii, and the relationships between the pathogen, habitat quality and small-mammal distribution are discussed. These findings have implications for public land management and management of fauna in areas prone to infection with P. cinnamomi.

Impoundment led to spatial trophic segregation of three closely related catfish species in the Three Gorges Reservoir, China

2020 ◽  
Vol 71 (7) ◽  
pp. 750
Author(s):  
Chuansong Liao ◽  
Sibao Chen ◽  
Sandra Bibiana Correa ◽  
Wei Li ◽  
Tanglin Zhang ◽  
...  
Keyword(s):  
Food Availability ◽  
Three Gorges Reservoir ◽  
Food Resource ◽  
Niche Overlap ◽  
Diet Breadth ◽  
Three Gorges ◽  
Lower Section ◽  
Resource Base ◽  
The Three Gorges Reservoir ◽  
The Three Gorges

The construction of the Three Gorges Reservoir (TGR), the largest dam in the world, created novel spatial and seasonal fluctuations in food availability along the Yangtze River. We studied changes in diet and niche overlap of three co-occurring catfish species between the upper and lower sections of the TGR and across four hydrological seasons to investigate whether the diets of native catfish species reflect the fluctuations in food availability. Zoobenthos dominated the diets of the three species in the upper section, but shrimp made the bulk of the diet in the lower section. This was the case in every season except during the rising-water season when all three species increased the consumption of allochthonous foods. Diet breadth was significantly broader in the upper section relative to the lower section, and expanded during the rising-water season in the lower section. Niche overlap was significantly lower in the upper section than in the lower section. A non-significant trend of reduced niche overlap during the rising-water season was observed in both sections. Our results suggest that, in less than a decade, dietary plasticity facilitated the adaptation of these species to novel habitats and a shifted food-resource base formed by the impoundment.

scholarly journals Selective Breeding for Low and High Varroa destructor Growth in Honey Bee (Apis mellifera) Colonies: Initial Results of Two Generations

Insects ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 864
Author(s):  
Alvaro De la Mora ◽  
Berna Emsen ◽  
Nuria Morfin ◽  
Daniel Borges ◽  
Les Eccles ◽  
...  
Keyword(s):  
Apis Mellifera ◽  
Honey Bee ◽  
Varroa Destructor ◽  
Winter Mortality ◽  
Genotypic Differences ◽  
Two Generations ◽  
Selection For ◽  
Bidirectional Selection ◽  
Future Work ◽  
Initial Results

After two years of bidirectional selection for low and high rates of Varroa destructor population growth (LVG and HVG, respectively) in honey bee (Apis mellifera) colonies in Ontario, Canada, significant differences between the two genotypes were observed. LVG colonies had V. destructor population increases over the summer of 1.7 fold compared to 9.6 fold for HVG colonies by Generation 2. Additionally, HVG colonies had significantly higher mite infestation rates in adult bees compared to LVG colonies for both selected generations. DWV prevalence and levels were significantly higher in HVG colonies than in LVG colonies in Generation 1 but not in Generation 2. Winter mortality rates of Generation 1 colonies were significantly different at 26% and 14% for the HVG and LVG genotypes, respectively. The results of this study thus far indicate that selection for LVG may result in colonies with lower V. destructor infestation rates, lower prevalence, and levels of DWV and higher colony winter survivorship. Future work will focus on determining what mechanisms are responsible for the genotypic differences, estimating genetic parameters, and molecular analyses of the genotypes to identify candidate genes associated with resistance to V. destructor and DWV that could potentially be used for marker-assisted selection.

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