scholarly journals Evolutionary stasis and lability in thermal physiology in a group of tropical lizards

2014 ◽  
Vol 281 (1778) ◽  
pp. 20132433 ◽  
Author(s):  
Martha M. Muñoz ◽  
Maureen A. Stimola ◽  
Adam C. Algar ◽  
Asa Conover ◽  
Anthony J. Rodriguez ◽  
...  
Keyword(s):  
Cold Tolerance ◽  
Heat Tolerance ◽  
Climate Warming ◽  
Physiological Traits ◽  
Physiological Adaptation ◽  
Night Time ◽  
Thermal Environments ◽  
Evolutionary Response ◽  
Lower Temperature ◽  
Similar Body

Understanding how quickly physiological traits evolve is a topic of great interest, particularly in the context of how organisms can adapt in response to climate warming. Adjustment to novel thermal habitats may occur either through behavioural adjustments, physiological adaptation or both. Here, we test whether rates of evolution differ among physiological traits in the cybotoids, a clade of tropical Anolis lizards distributed in markedly different thermal environments on the Caribbean island of Hispaniola. We find that cold tolerance evolves considerably faster than heat tolerance, a difference that results because behavioural thermoregulation more effectively shields these organisms from selection on upper than lower temperature tolerances. Specifically, because lizards in very different environments behaviourally thermoregulate during the day to similar body temperatures, divergent selection on body temperature and heat tolerance is precluded, whereas night-time temperatures can only be partially buffered by behaviour, thereby exposing organisms to selection on cold tolerance. We discuss how exposure to selection on physiology influences divergence among tropical organisms and its implications for adaptive evolutionary response to climate warming.

scholarly journals Enhancing the heat tolerance of reef-building corals to future warming

2021 ◽  
Vol 7 (34) ◽  
pp. eabg6070 ◽  
Author(s):  
Emily J. Howells ◽  
David Abrego ◽  
Yi Jin Liew ◽  
John A. Burt ◽  
Eli Meyer ◽  
...  
Keyword(s):  
Heat Tolerance ◽  
Climate Warming ◽  
Survival Rates ◽  
High Heat ◽  
Immune Functions ◽  
Population Declines ◽  
Thermal Environments ◽  
The World ◽  
Future Warming ◽  
Shock Proteins

Reef-building corals thriving in extreme thermal environments may provide genetic variation that can assist the evolution of populations to rapid climate warming. However, the feasibility and scale of genetic improvements remain untested despite ongoing population declines from recurrent thermal stress events. Here, we show that corals from the hottest reefs in the world transfer sufficient heat tolerance to a naïve population sufficient to withstand end-of-century warming projections. Heat survival increased up to 84% when naïve mothers were selectively bred with fathers from the hottest reefs because of strong heritable genetic effects. We identified genomic loci associated with tolerance variation that were enriched for heat shock proteins, oxidative stress, and immune functions. Unexpectedly, several coral families exhibited survival rates and genomic associations deviating from origin predictions, including a few naïve purebreds with exceptionally high heat tolerance. Our findings highlight previously uncharacterized enhanced and intrinsic potential of coral populations to adapt to climate warming.

Correction to: Genetic diversity and genetic variation in morpho-physiological traits to improve heat tolerance in Spring barley

2018 ◽  
Vol 46 (2) ◽  
pp. 2597-2597
Author(s):  
Ahmed Sallam ◽  
Ahmed Amro ◽  
Ammar Elakhdar ◽  
Mona F. A. Dawood ◽  
Toshihiro Kumamaru ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Heat Tolerance ◽  
Spring Barley ◽  
Physiological Traits

scholarly journals A widespread thermodynamic effect, but maintenance of biological rates through space across life's major domains

2018 ◽  
Vol 285 (1890) ◽  
pp. 20181775 ◽  
Author(s):  
Jesper G. Sørensen ◽  
Craig R. White ◽  
Grant A. Duffy ◽  
Steven L. Chown
Keyword(s):  
Temperature Compensation ◽  
Large Scale ◽  
Positive Relationship ◽  
Alternative Hypothesis ◽  
Developmental Rate ◽  
Physiological Adaptation ◽  
Thermal Environments ◽  
Maximal Performance ◽  
Thermodynamic Effect ◽  
Performance Rate

For over a century, the hypothesis of temperature compensation, the maintenance of similar biological rates in species from different thermal environments, has remained controversial. An alternative idea, that fitness is greater at higher temperatures (the thermodynamic effect), has gained increasing traction. This alternative hypothesis is also being used to understand large-scale biodiversity responses to environmental change. Yet evidence in favour of each of these contrasting hypotheses continues to emerge. In consequence, the fundamental nature of organismal thermal responses and its implications remain unresolved. Here, we investigate these ideas explicitly using a global dataset of 619 observations of four categories of organismal performance, spanning 14 phyla and 403 species. In agreement with both hypotheses, we show a positive relationship between the temperature of maximal performance rate ( T opt ) and environmental temperature ( T env ) for developmental rate and locomotion speed, but not growth or photosynthesis rate. Next, we demonstrate that relationships between T env and the maximal performance rate ( U max ) are rarely significant and positive, as expected if a thermodynamic effect predominates. By contrast, a positive relationship between T opt and U max is always present, but markedly weaker than theoretically predicted. These outcomes demonstrate that while some form of thermodynamic effect exists, ample scope is present for biochemical and physiological adaptation to thermal environments in the form of temperature compensation.

scholarly journals Social Group Size and Shelter Availability Influence Individual Metabolic Traits in a Social Fish

2021 ◽  
Author(s):  
Emmanuelle Chrétien ◽  
Daniel Boisclair ◽  
Steven J Cooke ◽  
Shaun S Killen
Keyword(s):  
Metabolic Rate ◽  
Group Size ◽  
Social Group ◽  
Physiological Traits ◽  
Metabolic Rates ◽  
Night Time ◽  
The Social ◽  
Before And After ◽  
Social Treatment ◽  
Shelter Availability

Abstract Group living is widespread among animal species and yields both costs and benefits. Presence of conspecifics can restrict or enhance the expression of individual behaviour, and the recent social environment is thought to affect behavioural responses in later contexts, even when individuals are alone. However, little is known about how social group size influences the expression of individual physiological traits, including metabolic rates. There is some evidence that shoaling can reduce fish metabolic rates but this variable may be affected by habitat conditions such as shelter availability via density-dependent processes. We investigated how social group size and shelter availability influence Eurasian minnow Phoxinus phoxinus metabolic rates estimated by respirometry. Respirometry trials were conducted on fish in isolation before and after they were housed for three weeks in a social treatment consisting in a specific group size (n = 4 or 8) and shelter availability (presence or absence of plant shelter in the experimental tank). Plant shelter was placed over respirometers for half of the duration of the respirometry trials, allowing estimation of minimum day-time and night-time metabolic rates in both conditions (in the presence or absence of plant shelter). Standard metabolic rate (SMR), maximum metabolic rate (MMR), and aerobic scope (AS) were also estimated over the entire trial. Minimum day-time and night-time metabolic rates estimated while in presence of plant shelter were lower than when estimated in absence of plant shelter, both before and after individuals were housed in their social treatment. After the social treatment, SMR were higher for fish that were held in groups of four as compared to that of fish held in groups of eight while MMR showed no difference. Plant shelter availability during the social treatments did not influence SMR or MMR. Our results suggest that social group size may directly influence energy demands of individuals, highlighting the importance of understanding the role of group size on variations in physiological traits associated with energy expenditure.

Arboreality drives heat tolerance while elevation drives cold tolerance in tropical rainforest ants

Ecology ◽  
2021 ◽  
Author(s):  
Lily Leahy ◽  
Brett R. Scheffers ◽  
Stephen E. Williams ◽  
Alan N. Andersen
Keyword(s):  
Cold Tolerance ◽  
Heat Tolerance ◽  
Tropical Rainforest

Thermal diversity of North American ant communities: Cold tolerance but not heat tolerance tracks ecosystem temperature

2020 ◽  
Vol 29 (9) ◽  
pp. 1486-1494 ◽  
Author(s):  
Jelena Bujan ◽  
Karl A. Roeder ◽  
Kirsten Beurs ◽  
Michael D. Weiser ◽  
Michael Kaspari
Keyword(s):  
Cold Tolerance ◽  
Heat Tolerance ◽  
North American ◽  
Ant Communities ◽  
Thermal Diversity

scholarly journals Thermal tolerance patterns across latitude and elevation

2019 ◽  
Vol 374 (1778) ◽  
pp. 20190036 ◽  
Author(s):  
Jennifer Sunday ◽  
Joanne M. Bennett ◽  
Piero Calosi ◽  
Susana Clusella-Trullas ◽  
Sarah Gravel ◽  
...  
Keyword(s):  
Cold Tolerance ◽  
Heat Tolerance ◽  
Thermal Tolerance ◽  
Large Scale ◽  
Global Climate ◽  
Climate Extremes ◽  
Species Traits ◽  
Acclimation Temperature ◽  
Tolerance Limits ◽  
Thermal Limits

Linking variation in species' traits to large-scale environmental gradients can lend insight into the evolutionary processes that have shaped functional diversity and future responses to environmental change. Here, we ask how heat and cold tolerance vary as a function of latitude, elevation and climate extremes, using an extensive global dataset of ectotherm and endotherm thermal tolerance limits, while accounting for methodological variation in acclimation temperature, ramping rate and duration of exposure among studies. We show that previously reported relationships between thermal limits and latitude in ectotherms are robust to variation in methods. Heat tolerance of terrestrial ectotherms declined marginally towards higher latitudes and did not vary with elevation, whereas heat tolerance of freshwater and marine ectotherms declined more steeply with latitude. By contrast, cold tolerance limits declined steeply with latitude in marine, intertidal, freshwater and terrestrial ectotherms, and towards higher elevations on land. In all realms, both upper and lower thermal tolerance limits increased with extreme daily temperature, suggesting that different experienced climate extremes across realms explain the patterns, as predicted under the Climate Extremes Hypothesis . Statistically accounting for methodological variation in acclimation temperature, ramping rate and exposure duration improved model fits, and increased slopes with extreme ambient temperature. Our results suggest that fundamentally different patterns of thermal limits found among the earth's realms may be largely explained by differences in episodic thermal extremes among realms, updating global macrophysiological ‘rules’. This article is part of the theme issue ‘Physiological diversity, biodiversity patterns and global climate change: testing key hypotheses involving temperature and oxygen’.

Assessing genetic variation for heat stress tolerance in Indian bread wheat genotypes using morpho-physiological traits and molecular markers

2016 ◽  
Vol 15 (6) ◽  
pp. 539-547 ◽  
Author(s):  
P. Sharma ◽  
S. Sareen ◽  
M. Saini ◽  
Shefali
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Heat Stress ◽  
Molecular Markers ◽  
Heat Tolerance ◽  
Polymorphic Information Content ◽  
Physiological Traits ◽  
Phenotypic Traits ◽  
Phenotypic Data ◽  
Wheat Genotypes

AbstractHeat stress greatly limits the productivity of wheat in many regions. Knowledge on the degree of genetic diversity of wheat varieties along with their selective traits will facilitate the development of high yielding, stress-tolerant wheat cultivar. The objective of this study were to determine genetic variation in morpho-physiological traits associated with heat tolerance in 30 diverse wheat genotypes and to examine genetic diversity and relationship among the genotypes varying heat tolerance using molecular markers. Phenotypic data of 15 traits were evaluated for heat tolerance under non-stress and stress conditions for two consecutive years. A positive and significant correlation among cell membrane stability, canopy temperature depression, biomass, susceptibility index and grain yield was shown. Genetic diversity assessed by 41 polymorphic simple sequence repeat (SSR) markers was compared with diversity evaluated for 15 phenotypic traits averaged over stress and non-stress field conditions. The mean polymorphic information content for SSR value was 0.38 with range of 0.12–0.75. Based on morpho-physiological traits and genotypic data, three groups were obtained based on their tolerance (HHT, MHT and LHT) levels. Analysis of molecular variance explained 91.7% of the total variation could be due to variance within the heat tolerance genotypes. Genetic diversity among HHT was higher than LHT genotypes and HHT genotypes were distributed among all cluster implied that genetic basis of heat tolerance in these genotypes was different thereby enabling the wheat breeders to combine these diverse sources of genetic variation to improve heat tolerance in wheat breeding programme.

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