Divergence and ontogenetic coupling of larval behaviour and thermal reaction norms in three closely related butterflies

Genetic trade-offs such as between generalist–specialist strategies can be masked by changes in compensatory processes involving energy allocation and acquisition which regulation depends on the state of the individual and its ecological surroundings. Failure to account for such state dependence may thus lead to misconceptions about the trade-off structure and nature of constraints governing reaction norm evolution. Using three closely related butterflies, we first show that foraging behaviours differ between species and change remarkably throughout ontogeny causing corresponding differences in the thermal niches experienced by the foraging larvae. We further predicted that thermal reaction norms for larval growth rate would show state-dependent variation throughout development as a result of selection for optimizing feeding strategies in the respective foraging niches of young and old larvae. We found substantial developmental plasticity in reaction norms that was species-specific and reflected the different ontogenetic niche shifts. Any conclusions regarding constraints on performance curves or species-differentiation in thermal physiology depend on when reaction norms were measured. This demonstrates that standardized estimates at single points in development, or in general, allow variation in only one ecological dimension, may sometimes provide incomplete information on reaction norm constraints.

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Do Differences in Latitudinal Distributions of Species and Organelle Haplotypes Reflect Thermal Reaction Norms Within the Emiliania/Gephyrocapsa Complex?

Frontiers in Marine Science ◽

10.3389/fmars.2021.785763 ◽

2021 ◽

Vol 8 ◽

Author(s):

Peter von Dassow ◽

Paula Valentina Muñoz Farías ◽

Sarah Pinon ◽

Esther Velasco-Senovilla ◽

Simon Anguita-Salinas

Keyword(s):

Local Adaptation ◽

Coastal Upwelling ◽

Environmental Gradients ◽

Reaction Norm ◽

Emiliania Huxleyi ◽

Thermal Reaction ◽

Reaction Norms ◽

Thermal Niche ◽

Significant Difference ◽

The Difference

The cosmopolitan phytoplankter Emiliania huxleyi contrasts with its closest relatives that are restricted to narrower latitudinal bands, making it interesting for exploring how alternative outcomes in phytoplankton range distributions arise. Mitochondrial and chloroplast haplogroups within E. huxleyi are shared with their closest relatives: Some E. huxleyi share organelle haplogroups with Gephyrocapsa parvula and G. ericsonii which inhabit lower latitudes, while other E. huxleyi share organelle haplogroups with G. muellerae, which inhabit high latitudes. We investigated whether the phylogeny of E. huxleyi organelles reflects environmental gradients, focusing on the Southeast Pacific where the different haplogroups and species co-occur. There was a high congruence between mitochondrial and chloroplast haplogroups within E. huxleyi. Haplogroup II of E. huxleyi is negatively associated with cooler less saline waters, compared to haplogroup I, both when analyzed globally and across temporal variability at the small special scale of a center of coastal upwelling at 30° S. A new mitochondrial haplogroup Ib detected in coastal Chile was associated with warmer waters. In an experiment focused on inter-species comparisons, laboratory-determined thermal reaction norms were consistent with latitudinal/thermal distributions of species, with G. oceanica exhibiting warm thermal optima and tolerance and G. muellerae exhibiting cooler thermal optima and tolerances. Emiliania huxleyi haplogroups I and II tended to exhibit a wider thermal niche compared to the other Gephyrocapsa, but no differences among haplogroups within E. huxleyi were found. A second experiment, controlling for local adaptation and time in culture, found a significant difference between E. huxleyi haplogroups. The difference between I and II was of the expected sign, but not the difference between I and Ib. The differences were small (≤1°C) compared to differences reported previously within E. huxleyi by local adaptation and even in-culture evolution. Haplogroup Ib showed a narrower thermal niche. The cosmopolitanism of E. huxleyi might result from both wide-spread generalist phenotypes and specialist phenotypes, as well as a capacity for local adaptation. Thermal reaction norm differences can well explain the species distributions but poorly explain distributions among mitochondrial haplogroups within E. huxleyi. Perhaps organelle haplogroup distributions reflect historical rather than selective processes.

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Impact of Developmental Temperatures On The Repeatability of Thermal Plasticity in Metabolic Rate

10.32942/osf.io/kp2gd ◽

2021 ◽

Author(s):

Fonti Kar ◽

Shinichi Nakagawa ◽

Daniel W.A. Noble

Keyword(s):

Metabolic Rate ◽

Population Level ◽

Reaction Norm ◽

Thermal Reaction ◽

Reaction Norms ◽

Thermal Plasticity ◽

Credible Intervals ◽

Hot Environments ◽

Plastic Responses ◽

Early Developmental

Phenotypic plasticity is an important mechanism that allows populations to adjust to changing environments. Plastic responses induced by early life experiences can have lasting impacts on how individuals respond to environmental variation later in life (i.e., reversible plasticity). Developmental environments can also influence repeatability of plastic responses thereby altering the capacity for reaction norms to respond to selection. Here, we compared metabolic thermal reaction norms in lizards (Lampropholis delicata) that were incubated at two developmental temperatures (ncold = 26, nhot = 25). We repeatedly measured individual reaction norms across six acute temperatures 10 times over ~3.5 months (nobs = 3,818) to estimate the repeatability of average metabolic rate (intercept) and thermal plasticity (slope). The intercept and the slope of the population-level thermal reaction norm did not change with developmental temperatures. Repeatability of average metabolic rate was, on average, 10% lower in hot incubated lizards and was stable across acute temperatures. The slope of the reaction norm was moderately repeatable (R = 0.44, 95% CI = 0.035 – 0.93) suggesting that individual metabolic rate changed consistently with acute temperature, although credible intervals were quite broad. Importantly, reaction norm repeatability did not depend on early developmental temperature. Our work implies that thermal plasticity has the capacity to evolve, despite there being less consistent variation in metabolic rate under hot environments. This capacity for thermal plasticity to evolve will be increasingly more important for terrestrial ectotherms living in changing climate.

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Thermal reaction norms in sperm performance of Atlantic cod (Gadus morhua)

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f10-001 ◽

2010 ◽

Vol 67 (3) ◽

pp. 498-510 ◽

Cited By ~ 28

Author(s):

Craig F. Purchase ◽

Ian A.E. Butts ◽

Alexandre Alonso-Fernández ◽

Edward A. Trippel

Keyword(s):

Phenotypic Plasticity ◽

Gadus Morhua ◽

Atlantic Cod ◽

Swimming Performance ◽

Common Garden ◽

Reaction Norm ◽

Thermal Reaction ◽

Reaction Norms ◽

Experimental Unit ◽

Environment Interaction

Phenotypic plasticity occurs when a genotype produces variable phenotypes under different environments; the shapes of such responses are known as norms of reaction. The genetic scale at which reaction norms can be determined is restricted by the experimental unit that can be exposed to variable environments. This has limited their description beyond the family level in higher organisms, thus hindering our understanding of differences in plasticity at the scale of the individual. Using a three-year common-garden experiment, we quantify reaction norms in sperm performance of individual genotypes within different families of Atlantic cod ( Gadus morhua ). Cod sperm showed phenotypic plasticity in swimming performance across temperatures (3, 6, 11, and 21 °C), but the pattern of the response depended upon how long sperm had been swimming (30, 60, 120, or 180 s), i.e., plasticity in plasticity. Sperm generally swam fastest at intermediate temperatures when first assessed at 30 s after activation. However, a significant genotype × environment interaction was present, indicating inter-individual differences in phenotypic plasticity. To our knowledge, this is the first study to describe variable sperm performance across environmental conditions as a reaction norm. The results have potential theoretical, conservation, and aquaculture implications.

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Hormones and Behavior

The Oxford Handbook of Evolutionary Psychology and Behavioral Endocrinology ◽

10.1093/oxfordhb/9780190649739.013.2 ◽

2019 ◽

pp. 11-26

Author(s):

Maren N. Vitousek ◽

Laura A. Schoenle

Keyword(s):

Life History ◽

Life Histories ◽

Life History Traits ◽

Developmental Plasticity ◽

Endocrine System ◽

Phenotypic Traits ◽

Social Environments ◽

Trade Offs ◽

And Behavior

Hormones mediate the expression of life history traits—phenotypic traits that contribute to lifetime fitness (i.e., reproductive timing, growth rate, number and size of offspring). The endocrine system shapes phenotype by organizing tissues during developmental periods and by activating changes in behavior, physiology, and morphology in response to varying physical and social environments. Because hormones can simultaneously regulate many traits (hormonal pleiotropy), they are important mediators of life history trade-offs among growth, reproduction, and survival. This chapter reviews the role of hormones in shaping life histories with an emphasis on developmental plasticity and reversible flexibility in endocrine and life history traits. It also discusses the advantages of studying hormone–behavior interactions from an evolutionary perspective. Recent research in evolutionary endocrinology has provided insight into the heritability of endocrine traits, how selection on hormone systems may influence the evolution of life histories, and the role of hormonal pleiotropy in driving or constraining evolution.

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Thermal reaction norms of key metabolic enzymes reflect divergent physiological and behavioral adaptations of closely related amphipod species

Scientific Reports ◽

10.1038/s41598-021-83748-2 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Lena Jakob ◽

Kseniya P. Vereshchagina ◽

Anette Tillmann ◽

Lorena Rivarola-Duarte ◽

Denis V. Axenov-Gribanov ◽

...

Keyword(s):

Lactate Dehydrogenase ◽

Lake Baikal ◽

Enzyme Activities ◽

Large Scale ◽

Metabolic Enzymes ◽

Thermal Reaction ◽

Reaction Norms ◽

Ecological Niches ◽

Amphipod Species ◽

Thermal Plasticity

AbstractLake Baikal is inhabited by more than 300 endemic amphipod species, which are narrowly adapted to certain thermal niches due to the high interspecific competition. In contrast, the surrounding freshwater fauna is commonly represented by species with large-scale distribution and high phenotypic thermal plasticity. Here, we investigated the thermal plasticity of the energy metabolism in two closely-related endemic amphipod species from Lake Baikal (Eulimnogammarus verrucosus; stenothermal and Eulimnogammarus cyaneus; eurythermal) and the ubiquitous Holarctic amphipod Gammarus lacustris (eurythermal) by exposure to a summer warming scenario (6–23.6 °C; 0.8 °C d−1). In concert with routine metabolic rates, activities of key metabolic enzymes increased strongly with temperature up to 15 °C in E. verrucosus, whereupon they leveled off (except for lactate dehydrogenase). In contrast, exponential increases were seen in E. cyaneus and G. lacustris throughout the thermal trial (Q10-values: 1.6–3.7). Cytochrome-c-oxidase, lactate dehydrogenase, and 3-hydroxyacyl-CoA dehydrogenase activities were found to be higher in G. lacustris than in E. cyaneus, especially at the highest experimental temperature (23.6 °C). Decreasing gene expression levels revealed some thermal compensation in E. cyaneus but not in G. lacustris. In all species, shifts in enzyme activities favored glycolytic energy generation in the warmth. The congruent temperature-dependencies of enzyme activities and routine metabolism in E. verrucosus indicate a strong feedback-regulation of enzymatic activities by whole organism responses. The species-specific thermal reaction norms reflect the different ecological niches, including the spatial distribution, distinct thermal behavior such as temperature-dependent migration, movement activity, and mating season.

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Host plant adaptation and the evolution of thermal reaction norms

Oecologia ◽

10.1007/s00442-011-2206-7 ◽

2011 ◽

Vol 169 (2) ◽

pp. 353-360 ◽

Cited By ~ 14

Author(s):

Sarah E. Diamond ◽

Joel G. Kingsolver

Keyword(s):

Host Plant ◽

Thermal Reaction ◽

Reaction Norms ◽

Plant Adaptation ◽

Host Plant Adaptation

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Variation in growth and instar number in field and laboratory Manduca sexta

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2006.0036 ◽

2007 ◽

Vol 274 (1612) ◽

pp. 977-981 ◽

Cited By ~ 48

Author(s):

Joel G Kingsolver

Keyword(s):

North Carolina ◽

Body Size ◽

Manduca Sexta ◽

Growth Rates ◽

Developmental Plasticity ◽

Larval Growth ◽

Physiological Control ◽

Larval Instars ◽

Laboratory Colony ◽

Early Larval Development

The tobacco hornworm Manduca sexta has been an important model system for understanding physiological control of growth, development and metamorphosis of insects for more than half a century. Like all Manduca , M. sexta typically has five larval instars, with developmental commitment to metamorphosis occurring early in the 5th (final) instar. Here we show that M. sexta from a field population in North Carolina (USA) shows substantial intraspecific variation in the number of larval instars when feeding on a modified artificial diet. Individuals with six instars consistently exhibited slower growth rates during early larval development than individuals with five instars. The frequency of individuals with six instars decreased with increased rearing temperature. In contrast, M. sexta from a laboratory colony consistently had five instars, and had more rapid larval growth rates than M. sexta from the field. We identify a threshold body size at the start of the 5th instar that predicts whether an individual will have five (greater than 600 mg) or six instars (less than 600 mg). Variation in field populations in Manduca provides an important resource for understanding physiological control, developmental plasticity and evolution of growth rate, body size and instar number.

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