Metabolic power budgeting and adaptive strategies in zoology: examples from scallops and fishThe present review is one of a series of occasional review articles that have been invited by the Editors and will feature the broad range of disciplines and expertise represented in our Editorial Advisory Board.

2010 ◽  
Vol 88 (8) ◽  
pp. 753-763 ◽  
Author(s):  
Helga Guderley ◽  
Hans Otto Pörtner

Evolutionary explanations of the adaptive value of animal characteristics are often expressed in energetic terms, but unless they are accompanied by demonstrations of limited energy availability, they remain speculative. In this review, we argue that metabolic power budgeting provides easily testable mechanisms through which energetically efficient attributes could become adaptive. Given each organism’s maximal aerobic (and metabolic) capacity, available metabolic power (energy use per unit time) is limited and must be partitioned between different processes. This leads to compromises among the major fitness functions of growth, locomotor activity, and reproductive investment. As examples of such conflicts, we examine the compromise among growth, reproduction, and predator avoidance in scallops, as well as the means whereby thermal limitations on oxygen uptake reflect the geographical distribution limits and associated energetic trade-offs of temperate zone and polar fishes. These examples show several means whereby the budgeting of aerobic power is implicated in the major fitness trade-offs faced by animals.

Author(s):  
Thassya C. dos Santos Schmidt ◽  
Doug E. Hay ◽  
Svein Sundby ◽  
Jennifer A. Devine ◽  
Guðmundur J. Óskarsson ◽  
...  

AbstractLife-history traits of Pacific (Clupea pallasii) and Atlantic (Clupea harengus) herring, comprising both local and oceanic stocks subdivided into summer-autumn and spring spawners, were extensively reviewed. The main parameters investigated were body growth, condition, and reproductive investment. Body size of Pacific herring increased with increasing latitude. This pattern was inconsistent for Atlantic herring. Pacific and local Norwegian herring showed comparable body conditions, whereas oceanic Atlantic herring generally appeared stouter. Among Atlantic herring, summer and autumn spawners produced many small eggs compared to spring spawners, which had fewer but larger eggs—findings agreeing with statements given several decades ago. The 26 herring stocks we analysed, when combined across distant waters, showed clear evidence of a trade-off between fecundity and egg size. The size-specific individual variation, often ignored, was substantial. Additional information on biometrics clarified that oceanic stocks were generally larger and had longer life spans than local herring stocks, probably related to their longer feeding migrations. Body condition was only weakly, positively related to assumingly in situ annual temperatures (0–30 m depth). Contrarily, body growth (cm × y−1), taken as an integrator of ambient environmental conditions, closely reflected the extent of investment in reproduction. Overall, Pacific and local Norwegian herring tended to cluster based on morphometric and reproductive features, whereas oceanic Atlantic herring clustered separately. Our work underlines that herring stocks are uniquely adapted to their habitats in terms of trade-offs between fecundity and egg size whereas reproductive investment mimics the productivity of the water in question.


1997 ◽  
Vol 75 (4) ◽  
pp. 542-548 ◽  
Author(s):  
P. H. Niewiarowski ◽  
J. D. Congdon ◽  
A. E. Dunham ◽  
L. J. Vitt ◽  
D. W. Tinkle

Potential costs and benefits of tail autotomy in lizards have been inferred almost exclusively from experimental study in semi-natural enclosures and from indirect comparative evidence from natural populations. We present complementary evidence of the costs of tail autotomy to the lizard Uta stansburiana from detailed demographic study of a natural population. On initial capture, we broke the tails of a large sample of free-ranging hatchlings (560) and left the tails of another large sample (455) intact, and then followed subsequent hatchling growth and survival over a 3-year period. Surprisingly, in 1 out of the 3 years of study, survival of female hatchlings with broken tails exceeded that of female hatchlings with intact tails. Furthermore, no effects of tail loss on survivorship were detected for male hatchlings. However, in 2 years when recaptures were very frequent (1961, 1962), growth rates of hatchlings with broken tails were significantly slower than those of their counterparts with intact tails. We discuss our results in the broader context of estimating the relative costs and benefits of tail autotomy in natural populations, and suggest that long-term demographic studies will provide the best opportunity to assess realized fitness costs and benefits with minimum bias. We also describe how experimentally induced tail autotomy can be used as a technique to complement experimental manipulation of reproductive investment in the study of life-history trade-offs.


2018 ◽  
Vol 13 (1) ◽  
pp. 112-114 ◽  
Author(s):  
Carlo Capelli

Purpose: To analyze best 1-h unaccompanied performances of master athletes in ages ranging from 35 to 105 y to estimate the decay of maximal aerobic power (MAP) across the spectrum of age. Methods: MAP at the various ages was estimated by computing the metabolic power () maintained to cover the distances during best 1-h unaccompanied performances established by master athletes of different classes of age and by assuming that they were able to maintain an equal to 88% of their MAP during 1 h of exhaustive exercise. Results: MAP started monotonically decreasing at 47 y of age. Thereafter, it showed an average rate of decrease of ∼14% for the decades up to 105 y of age, similar to other classes of master athletes. Conclusions: The results confirm, by extending the analysis to centennial subjects, that MAP seems to start declining from the middle of the 5th decade of age, with an average percentage decay that is faster than that traditionally reported, even when one maintains a very active lifestyle. The proposed approach may be applied to other types of human locomotion for which the relationship between speed and is known.


2018 ◽  
Vol 285 (1892) ◽  
pp. 20182141 ◽  
Author(s):  
Stefania Casagrande ◽  
Michaela Hau

The trade-off between reproductive investment and survival is central to life-history theory, but the relative importance and the complex interactions among the physiological mechanisms mediating it are still debated. Here we experimentally tested whether baseline glucocorticoid hormones, the redox system or their interaction mediate reproductive investment–survival trade-offs in wild great tits ( Parus major ). We increased the workload of parental males by clipping three feathers on each wing, and 5 days later determined effects on baseline corticosterone concentrations (Cort), redox state (reactive oxygen metabolites, protein carbonyls, glutathione peroxidase [GPx], total non-enzymatic antioxidants), body mass, body condition, reproductive success and survival. Feather-clipping did not affect fledgling numbers, chick body condition, nest provisioning rates or survival compared with controls. However, feather-clipped males lost mass and increased both Cort and GPx concentrations. Within feather-clipped individuals, GPx increases were positively associated with reproductive investment (i.e. male nest provisioning). Furthermore, within all individuals, males that increased GPx suffered reduced survival rates. Baseline Cort increases were related to mass loss but not to redox state, nest provisioning or male survival. Our findings provide experimental evidence that changes in the redox system are associated with the trade-off between reproductive investment and survival, while baseline Cort may support this trade-off indirectly through a link with body condition. These results also emphasize that plastic changes in individuals, rather than static levels of physiological signals, may mediate life-history trade-offs.


Buildings ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 105 ◽  
Author(s):  
Nadia MIRABELLA ◽  
Martin RÖCK ◽  
Marcella Ruschi Mendes SAADE ◽  
Carolin SPIRINCKX ◽  
Marc BOSMANS ◽  
...  

Globally, the building sector is responsible for more than 40% of energy use and it contributes approximately 30% of the global Greenhouse Gas (GHG) emissions. This high contribution stimulates research and policies to reduce the operational energy use and related GHG emissions of buildings. However, the environmental impacts of buildings can extend wide beyond the operational phase, and the portion of impacts related to the embodied energy of the building becomes relatively more important in low energy buildings. Therefore, the goal of the research is gaining insights into the environmental impacts of various building strategies for energy efficiency requirements compared to the life cycle environmental impacts of the whole building. The goal is to detect and investigate existing trade-offs in current approaches and solutions proposed by the research community. A literature review is driven by six fundamental and specific research questions (RQs), and performed based on two main tasks: (i) selection of literature studies, and (ii) critical analysis of the selected studies in line with the RQs. A final sample of 59 papers and 178 case studies has been collected, and key criteria are systematically analysed in a matrix. The study reveals that the high heterogeneity of the case studies makes it difficult to compare these in a straightforward way, but it allows to provide an overview of current methodological challenges and research gaps. Furthermore, the most complete studies provide valuable insights in the environmental benefits of the identified energy performance strategies over the building life cycle, but also shows the risk of burden shifting if only operational energy use is focused on, or when a limited number of environmental impact categories are assessed.


2015 ◽  
pp. 123-140 ◽  
Author(s):  
Shahbaz Mushtaq ◽  
Tek N. Maraseni ◽  
Kathryn Reardon-Smith

2020 ◽  
Vol 15 (3) ◽  
pp. 308-316
Author(s):  
Bindu Shrestha ◽  
Sushil B Bajracharya ◽  
Sudarshan R Tiwari

The urban household has a high potential for energy saving to reduce carbon emission; however, it has been scant attention in Nepalese energy policy. Though sustainable development has set 2030 goals to achieve high impact on energy with a focus on women’ role, Nepal is still lagged for effective participating women properly in the energy sector. Urban women have a triple role with significant responsibility for household chores, and efficient cooking is one of pertinent attitudes to reduce energy in Kathmandu. Household energy is highly influenced by human behavior, energy culture, and practices, more significant role for shifting technology, that has less consideration in the policy. This paper aims to assess the energy practices identifying trade-offs of an energy transition to cleaner technology from the questionnaire survey, observation, interviews, and quantitative analysis in terms of a gender perspective. The analysis is based on energy cultures framework in gender perspective with primary attributes of cognitive norms, energy practices, and material culture to understand urban Kathmandu neighborhood. The field study showed that urban households are suffered from energy inaccessibility, inequality, and insecurity resulting in fuel stacking, socio-economic disparity, and environmental impacts. In conclusion, the energy-saving and reduced carbon emissions can be solved through prioritizing women’s role as a change of agent with active participation, incentives, two-way communication, and awareness to improve the situation.


2015 ◽  
Vol 282 (1821) ◽  
pp. 20151808 ◽  
Author(s):  
Paola Laiolo ◽  
Javier Seoane ◽  
Juan Carlos Illera ◽  
Giulia Bastianelli ◽  
Luis María Carrascal ◽  
...  

The fit between life histories and ecological niche is a paradigm of phenotypic evolution, also widely used to explain patterns of species co-occurrence. By analysing the lifestyles of a sympatric avian assemblage, we show that species' solutions to environmental problems are not unbound. We identify a life-history continuum structured on the cost of reproduction along a temperature gradient, as well as habitat-driven parental behaviour. However, environmental fit and trait convergence are limited by niche filling and by within-species variability of niche traits, which is greater than variability of life histories. Phylogeny, allometry and trade-offs are other important constraints: lifetime reproductive investment is tightly bound to body size, and the optimal allocation to reproduction for a given size is not established by niche characteristics but by trade-offs with survival. Life histories thus keep pace with habitat and climate, but under the limitations imposed by metabolism, trade-offs among traits and species' realized niche.


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