Causes and Consequences of Phenotypic Plasticity in Body Size

2009 ◽  
Author(s):  
Wolf Blanckenhorn
Keyword(s):  
Body Size ◽  
Phenotypic Plasticity

Ecology and biogeography in the introduction to “De bestiis marinis” by Georg Wilhelm Steller

2019 ◽  
Vol 46 (1) ◽  
pp. 63-74
Author(s):  
Stefano Mattioli
Keyword(s):  
Body Size ◽  
Phenotypic Plasticity ◽  
Geographical Distribution ◽  
Functional Traits ◽  
Marine Mammals ◽  
Main Part ◽  
Wide Distribution ◽  
Restricted Range ◽  
Direct Influence ◽  
Modern Biology

The rediscovery of the original, unedited Latin manuscript of Georg Wilhelm Steller's “De bestiis marinis” (“On marine mammals”), first published in 1751, calls for a new translation into English. The main part of the treatise contains detailed descriptions of four marine mammals, but the introduction is devoted to more general issues, including innovative speculation on morphology, ecology and biogeography, anticipating arguments and concepts of modern biology. Steller noted early that climate and food have a direct influence on body size, pelage and functional traits of mammals, potentially affecting reversible changes (phenotypic plasticity). Feeding and other behavioural habits have an impact on the geographical distribution of mammals. Species with a broad diet tend to have a wide distribution, whereas animals with a narrow diet more likely have only a restricted range. According to Steller, both sea and land then still concealed countless animals unknown to science.

scholarly journals Quantitative mismatch between empirical temperature-size rule slopes and predictions based on oxygen limitation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sigurd Einum ◽  
Claus Bech ◽  
Øystein Nordeide Kielland
Keyword(s):  
Body Size ◽  
Phenotypic Plasticity ◽  
Supply And Demand ◽  
Oxygen Limitation ◽  
Size Distributions ◽  
Deterministic Models ◽  
Future Studies ◽  
Temperature Regimes ◽  
Order Of Magnitude

AbstractIn ectotherms, adult body size commonly declines with increasing environmental temperature, a pattern known as the temperature-size rule. One influential hypothesis explaining this observation is that the challenge of obtaining sufficient oxygen to support metabolism becomes greater with increasing body size, and more so at high temperatures. Yet, previous models based on this hypothesis do not account for phenotypic plasticity in the physiology of organisms that counteracts oxygen limitation at high temperature. Here, we model the predicted strength of the temperature-size response using estimates of how both the oxygen supply and demand is affected by temperature when allowing for phenotypic plasticity in the aquatic ectotherm Daphnia magna. Our predictions remain highly inconsistent with empirical temperature-size responses, with the prior being close to one order of magnitude stronger than the latter. These results fail to provide quantitative support for the hypothesis that oxygen limitation drives temperature-size clines in aquatic ectotherms. Future studies into the role of oxygen limitation should address how the strength of the temperature-size response may be shaped by evolution under fluctuating temperature regimes. Finally, our results caution against applying deterministic models based on the oxygen limitation hypothesis when predicting future changes in ectotherm size distributions under climate change.

scholarly journals Morphometric differentiation and sexual dimorphism in Limnomedusa macroglossa (Duméril & Bibron, 1841) (Anura: Alsodidae) from Uruguay

2021 ◽  
Vol 16 (1) ◽  
pp. 11-25
Author(s):  
Valeria De Olivera-López ◽  
Arley Camargo ◽  
Raúl Maneyro
Keyword(s):  
Sexual Selection ◽  
Body Size ◽  
Sexual Dimorphism ◽  
Phenotypic Plasticity ◽  
Life History Strategies ◽  
Clinal Variation ◽  
Size And Shape ◽  
Secondary Sexual Characteristics ◽  
Sexual Characteristics ◽  
Morphological Differences

Intersexual morphological differences within a species occur in many traits, including body size and shape. Many processes that cause geographic variability in morphology have been proposed: population structure, phenotypic plasticity (environmental effects on development), and natural and/or sexual selection. Several hypotheses can explain patterns of sexual dimorphism in anurans, including natural or intra/inter-sexual selection, and differences in life history strategies between sexes. Limnomedusa macroglossa is considered a habitat specialist restricted to rocky outcrops in Brazil, Argentina, Paraguay, and Uruguay. We evaluated the extent of sexual (size and shape) dimorphism in L. macroglossa from Uruguay based on morphometrics and secondary sexual characteristics, while taking into account geographic variation. Sexual dimorphism in body size of adults was found, but multivariate analyses did not demonstrate the existence of significant differences in shape. There were also significant differences in body size and hind leg measurements among six hydrographic basins as a result from the phenotypic plasticity correlated with local temperature, representing a clinal variation along the latitudinal gradient of Uruguay. The sexual dimorphism found in body size is probably the consequence of higher growth rates and/or late sexual maturity in females, which favors larger body size for accommodating larger ovaries, and thus, higher reproductive output. 

scholarly journals Quantitative Mismatch Between Empirical Temperature-Size Rule Slopes and Predictions Based on Oxygen Limitation

2021 ◽  
Author(s):  
Sigurd Einum ◽  
Claus Bech ◽  
Øystein Nordeide Kielland
Keyword(s):  
Body Size ◽  
Phenotypic Plasticity ◽  
Supply And Demand ◽  
Oxygen Limitation ◽  
Size Distributions ◽  
Deterministic Models ◽  
Future Studies ◽  
Temperature Regimes ◽  
Order Of Magnitude

Abstract In ectotherms, adult body size commonly declines with increasing environmental temperature, a pattern known as the temperature-size rule. One influential hypothesis explaining this observation is that the challenge of obtaining sufficient oxygen to support metabolism becomes greater with increasing body size, and more so at high temperatures. Yet, previous models based on this hypothesis do not account for phenotypic plasticity in the physiology of organisms that counteracts oxygen limitation at high temperature. Here, we model the predicted strength of the temperature-size response using estimates of how both the oxygen supply and demand is affected by temperature when allowing for phenotypic plasticity in the aquatic ectotherm Daphnia magna. Our predictions remain highly inconsistent with empirical temperature-size responses, with the prior being close to one order of magnitude stronger than the latter. These results fail to provide quantitative support for the hypothesis that oxygen limitation drives temperature-size clines in aquatic ectotherms. Future studies into the role of oxygen limitation should address how the strength of the temperature-size response may be shaped by evolution under fluctuating temperature regimes. Finally, our results caution against applying deterministic models based on the oxygen limitation hypothesis when predicting future changes in ectotherm size distributions under climate change.

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