scholarly journals Size does matter — the eco-evolutionary effects of changing body size in fish

2020 ◽  
Vol 28 (3) ◽  
pp. 311-324
Author(s):  
Pauliina A. Ahti ◽  
Anna Kuparinen ◽  
Silva Uusi-Heikkilä
Keyword(s):  
Body Size ◽  
Dissolved Oxygen ◽  
Water Temperature ◽  
Evolutionary Potential ◽  
Predator Prey ◽  
Selective Agents ◽  
High Heritability ◽  
The Individual ◽  
Individual Body

Body size acts as a proxy for many fitness-related traits. Body size is also subject to directional selection from various anthropogenic stressors such as increasing water temperature, decreasing dissolved oxygen, fisheries, as well as natural predators. Changes in individual body size correlate with changes in fecundity, behaviour, and survival and can propagate through populations and ecosystems by truncating age and size structures and changing predator–prey dynamics. In this review, we will explore the causes and consequences of changing body size in fish in the light of recent literature and relevant theories. We will investigate the central role of body size in ecology by first discussing the main selective agents that influence body size: fishing, increasing water temperature, decreasing dissolved oxygen, and predation. We will then explore the impacts of these changes at the individual, population, and ecosystem levels. Considering the relatively high heritability of body size, we will discuss how a change in body size can leave a genetic signature in the population and translate to a change in the evolutionary potential of the species.

scholarly journals Molecular Politics, Wearables, and the Aretaic Shift in Biopolitical Governance

2020 ◽  
Vol 37 (3) ◽  
pp. 71-96
Author(s):  
Peter Lindner
Keyword(s):  
Human Body ◽  
Common Ground ◽  
New Technologies ◽  
Expert Knowledge ◽  
The Body ◽  
Life Itself ◽  
The Common ◽  
The Individual ◽  
Individual Body

Since the publication of Nikolas Rose’s ‘The Politics of Life Itself’ (2001) there has been vivid discussion about how biopolitical governance has changed over the last decades. This article uses what Rose terms ‘molecular politics’, a new socio-technical grip on the human body, as a contrasting background to ask anew his question ‘What, then, of biopolitics today?’ – albeit focusing not on advances in genetics, microbiology, and pharmaceutics, as he does, but on the rapid proliferation of wearables and other sensor-software gadgets. In both cases, new technologies providing information about the individual body are the common ground for governance and optimization, yet for the latter, the target is habits of moving, eating and drinking, sleeping, working and relaxing. The resulting profound differences are carved out along four lines: ‘somatic identities’ and a modified understanding of the body; the role of ‘expert knowledge’ compared to that of networks of peers and self-experimentation; the ‘types of intervention’ by which new technologies become effective in our everyday life; and the ‘post-discipline character’ of molecular biopolitics. It is argued that, taken together, these differences indicate a remarkable shift which could be termed aretaic: its focus is not ‘life itself’ but ‘life as it is lived’, and its modality are new everyday socio-technical entanglements and their more-than-human rationalities of (self-)governance.

Effet de certains paramètres physico-chimiques sur les relations prédateurs–proies dans les populations de copépodes cyclopoïdes des mares temporaires d'eau douce

1986 ◽  
Vol 64 (1) ◽  
pp. 8-11
Author(s):  
Louise Vallières ◽  
Antoine Aubin
Keyword(s):  
Organic Matter ◽  
Body Size ◽  
Dissolved Oxygen ◽  
Water Temperature ◽  
Feeding Ecology ◽  
Mineral Content ◽  
Abiotic Factors ◽  
Size Class ◽  
Regression Analyses ◽  
Physical And Chemical

Copepod populations of three temporary freshwater pools (Alnus unit, Carex unit, and Molinia unit) were studied using a standard approach (species versus abiotic factors) and a holistic one (body size and feeding ecology). Multiple regression analyses of data indicate that the physical and chemical features of water (temperature, pH, dissolved oxygen, mineral content, and depth) explain 62 to 98% of the variability of carnivorous copepods, while the abundance of their prey accounts for much less. No size class of prey seems to be preferred. The abundance of decaying organic matter, typical of such pools, would result in an overabundance of prey. Predators would then be under the control of nonalimentary factors.

The Role of Relative Body Size in a Predator-Prey Relationship between Dragonfly Naiads and Larval Anurans

Oikos ◽  
1985 ◽  
Vol 45 (1) ◽  
pp. 59 ◽  
Author(s):  
Joseph Travis ◽  
W. Hubert Keen ◽  
John Juilianna
Keyword(s):  
Body Size ◽  
Predator Prey ◽  
Larval Anurans ◽  
Relative Body Size

The Fossil Record of Predator-Prey Arms Races: Coevolution and Escalation Hypotheses

2002 ◽  
Vol 8 ◽  
pp. 353-374 ◽  
Author(s):  
Gregory P. Dietl ◽  
Patricia H. Kelley
Keyword(s):  
Species Interactions ◽  
Fossil Record ◽  
Top Down ◽  
Short Term ◽  
Arms Races ◽  
Predator Prey ◽  
Long Run ◽  
Selective Agents ◽  
History Of

Arms races between predators and prey may be driven by two related processes—escalation and coevolution. Escalation is enemy-driven evolution. In this top-down view of an arms race, the role of prey (with the exception of dangerous prey) is downplayed. In coevolution, two or more species change reciprocally in response to one another; prey are thought to drive the evolution of their predator, and vice versa. In the fossil record, the two processes are most reliably distinguished when the predator-prey system is viewed within the context of the other species that may influence the interaction, thus allowing for a relative ranking of the importance of selective agents. Detailed documentation of the natural history of living predator-prey systems is recommended in order to distinguish the processes in some fossil systems. A geographic view of species interactions and the processes driving their evolution may lead to a more diverse array of testable hypotheses on how predator-prey systems evolve and what constraints interactions impose on the evolution of organisms. Scale is important in evaluating the role of escalation and coevolution in the evolution of species interactions. If short-term reciprocal adaptation (via phenotypic plasticity or selection mosaics among populations) between predator and prey is a common process, then prey are likely to exert some selective pressure over their predators over the short term (on ecological time scales), but in the long run predators may still exert primary “top-down” control in directing evolution. On the scale of evolutionary time, predators of large effect likely control the overall directionality of evolution due to the inequalities of predator and prey in control of resources.

scholarly journals Predator–prey interactions and changing environments: who benefits?

2007 ◽  
Vol 362 (1487) ◽  
pp. 2095-2104 ◽  
Author(s):  
Mark V Abrahams ◽  
Marc Mangel ◽  
Kevin Hedges
Keyword(s):  
Dissolved Oxygen ◽  
Thermal Environment ◽  
Environmental Parameters ◽  
Theoretical Work ◽  
Environmental Data ◽  
Net Benefit ◽  
Predator Prey ◽  
Thermal Change ◽  
Potential Impact

While aquatic environments have long been thought to be more moderate environments than their terrestrial cousins, environmental data demonstrate that for some systems this is not so. Numerous important environmental parameters can fluctuate dramatically, notably dissolved oxygen, turbidity and temperature. The roles of dissolved oxygen and turbidity on predator–prey interactions have been discussed in detail elsewhere within this issue and will be considered only briefly here. Here, we will focus primarily on the role of temperature and its potential impact upon predator–prey interactions. Two key properties are of particular note. For temperate aquatic ecosystems, all piscine and invertebrate piscivores and their prey are ectothermic. They will therefore be subject to energetic demands that are significantly affected by environmental temperature. Furthermore, the physical properties of water, particularly its high thermal conductivity, mean that thermal microenvironments will not exist so that fine-scale habitat movements will not be an option for dealing with changing water temperature in lentic environments. Unfortunately, there has been little experimental analysis of the role of temperature on such predator–prey interactions, so we will instead focus on theoretical work, indicating that potential implications associated with thermal change are unlikely to be straightforward and may present a greater threat to predators than to their prey. Specifically, we demonstrate that changes in the thermal environment can result in a net benefit to cold-adapted species through the mechanism of predator–prey interactions.

scholarly journals Body Size of the Monomorphic AntLasius niger: Young Colonies along a Metal Pollution Gradient

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Irena M. Grześ ◽  
Mateusz Okrutniak ◽  
Gracjan Antosik
Keyword(s):  
Body Size ◽  
Metal Pollution ◽  
Morphological Changes ◽  
Morphological Diversity ◽  
The Body ◽  
Lasius Niger ◽  
Pollution Level ◽  
Head Width ◽  
The Individual ◽  
Individual Body

Metal pollution may cause the decrease in the individual body size. In ants, the morphological diversity within and between colonies may be much higher than that considered before, even in monomorphic ants. In this study we measured the body size, expressed as head width, ofLasius nigerworkers collected from 44 young colonies in their ergonomic stage along a well-known gradient exhibiting chronic metal pollution. We calculated statistics describing the body size distribution curve, namely, average, median, data range, skewness, and kurtosis. None of these statistics correlated with the pollution level. Contrary to our previous study performed on mature colonies, workers from young colonies do not display pollution-related morphological changes. The results stress the importance of developmental stage of colony on diversifying body size of the worker cast, in monomorphic ants living in metal-polluted areas.

scholarly journals Evolutionary approaches to autism- an overview and integration

2020 ◽  
Vol 13 (2) ◽  
Author(s):  
Annemie Ploeger ◽  
Frietson Galis
Keyword(s):  
Natural Selection ◽  
Reproductive Success ◽  
Neurodevelopmental Disorder ◽  
Developmental Perspective ◽  
Epistatic Interactions ◽  
High Intelligence ◽  
High Heritability ◽  
The Individual

Autism is a highly heritable neurodevelopmental disorder, which great- ly reduces reproductive success. The combination of high heritability and low re- productive success raises an evolutionary question: why was autism not eliminated  by natural selection? we review different perspectives on the evolution of autism  and propose an integration which emphasizes epistatic interactions between the ef- fects of genes during development. It is well-established that autism is a polygenic  disorder, and that the genes contributing to autism interact. If a disorder is poly- genic, it is likely that the genes underlying the disorder are also involved in traits  that are benefcial for the individual. For example, it is possible that genes involved in the development of autism are also involved in the development of intelligence. As intelligence is positively correlated with reproductive success, genes involved  in autism can possibly spread in the population. we propose that in most individu- als, the interactions between genes result in normal or high intelligence and the  absence of autism. However, in some unlucky situations, often in combination with spontaneous negative mutations, the interactions between genes can lead to the  development of autism (or other pathologies). Thus, the combination of high herita- bility and low reproductive success in autism can be explained from an evolution- ary developmental perspective that emphasizes the role of epistatic interactions in  polygenic disorders.

Introduction: Socialism to Be Embodied

2020 ◽  
Vol 34 (4) ◽  
pp. 802-816
Author(s):  
Maike Lehmann ◽  
Alexandra Oberländer
Keyword(s):  
Social Practice ◽  
The Body ◽  
Eastern Bloc ◽  
Eastern European ◽  
State And Society ◽  
Eastern European Countries ◽  
The Individual ◽  
The Impact ◽  
Individual Body

This article belongs to the special cluster, “Family, Gender and (dis)Abled Bodies after 1953”, guest-edited by Maike Lehmann and Alexandra Oberländer. While the ideal of the New Socialist Wo/Man was never fully realized and seems to have been abandoned across the Eastern Bloc after 1953, the question still arises what role individuals were to play within the socialist system. As dichotomous conceptualizations of state and society have been repeatedly criticized in recent years, we propose to look at how the role of the individual was imagined by different actors in Eastern European countries and how the ideals inherent in these imaginations were (to be) embodied. One possible avenue would be to explore the role of official language for subjectivization processes as they have been discussed during the last twenty years in Soviet studies. We, however, want to turn the attention towards the body and its role in shaping the individual in a cluster dealing with the impact family, gender, and dis/ability (were meant to) have on the formation of an individual body and its place within broader society. This is to explore some of the ways in which anybody could become somebody in socialist Eastern Europe and might help to shift the attention from dichotomous conceptualizations of political dogma and social practice towards an exploration of socialism as a diverse, yet specific cultural system.

Ecobiological survey of the brine shrimp Artemia salina from Sabkhet El Adhibet (south-east Tunisia)

2009 ◽  
Vol 89 (6) ◽  
pp. 1109-1116 ◽  
Author(s):  
Hachem Ben Naceur ◽  
Amel Ben Rejeb Jenhani ◽  
Mohamed Salah Romdhane
Keyword(s):  
Dissolved Oxygen ◽  
Water Temperature ◽  
Brine Shrimp ◽  
Artemia Salina ◽  
Chemical Parameters ◽  
Nutrient Analysis ◽  
Major Nutrient ◽  
The Individual ◽  
Physical And Chemical ◽  
Individual Fecundity

In order to provide a better characterization and understanding of the brine shrimp Artemia salina life-cycle, different ecological and biological parameters were taken out monthly during two periods from November 2005 to April 2006 and from November 2006 to April 2007 in Sabkhet El Adhibet (south-east Tunisia). Variation of water temperature, salinity, pH, dissolved oxygen, nutrients (orthophosphate, nitrites, nitrates and ammonium) and phytoplankton density were monitored. The Artemia population was also surveyed. Artemia were present in the site with salinity between 32.2 and 281.7 g l−1 and water temperature between 12.1 and 25.4°C. The pH ranged from 7.6 to 9 and dissolved oxygen concentration from 3.4 to 17.5 mg l−1. Minimum and maximum values of phytoplankton density were 0.19 and 14.59 106 cell l−1. In addition, the nutrient analysis registered showed that nitrate and ammonium represent the major nutrient. The Artemia population density fluctuated between 0.22 and 38.57 individuals per litre. The male:female ratio was dominated by the males. Artemia from Sabkhet El Adhibet showed variability in fecundity (total offspring and brood size) as well as in the ratio encystment/oviviparity. The individual fecundity fluctuates between 29.4 and 70.2 cysts and 17.8 and 69.8 nauplii. Finally, the influence of physical and chemical parameters as well as phytoplankton density over the Artemia population was noticed.

School Success and School Engagement of Immigrant Children and Adolescents

2013 ◽  
Vol 18 (2) ◽  
pp. 126-135 ◽  
Author(s):  
Frosso Motti-Stefanidi ◽  
Ann S. Masten
Keyword(s):  
Academic Achievement ◽  
Academic Success ◽  
Children And Adolescents ◽  
School Engagement ◽  
School Success ◽  
Immigrant Children ◽  
Integrative Model ◽  
High Stakes ◽  
The Individual

Academic achievement in immigrant children and adolescents is an indicator of current and future adaptive success. Since the future of immigrant youths is inextricably linked to that of the receiving society, the success of their trajectory through school becomes a high stakes issue both for the individual and society. The present article focuses on school success in immigrant children and adolescents, and the role of school engagement in accounting for individual and group differences in academic achievement from the perspective of a multilevel integrative model of immigrant youths’ adaptation ( Motti-Stefanidi, Berry, Chryssochoou, Sam, & Phinney, 2012 ). Drawing on this conceptual framework, school success is examined in developmental and acculturative context, taking into account multiple levels of analysis. Findings suggest that for both immigrant and nonimmigrant youths the relationship between school engagement and school success is bidirectional, each influencing over time the other. Evidence regarding potential moderating and mediating roles of school engagement for the academic success of immigrant youths also is evaluated.

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