scholarly journals Color change in a marine isopod is adaptive in reducing predation

2015 ◽  
Vol 61 (4) ◽  
pp. 739-748 ◽  
Author(s):  
Kristin M. Hultgren ◽  
Hannah Mittelstaedt
Keyword(s):  
Brown Algae ◽  
Color Change ◽  
Adaptive Function ◽  
Background Matching ◽  
Fucus Distichus ◽  
Fitness Consequences ◽  
Color Differences ◽  
Fitness Benefits ◽  
Change Mechanisms ◽  
Algal Diet

Abstract Although background matching is a common form of camouflage across a wide diversity of animals, there has been surprisingly little experimental work testing the fitness consequences of this camouflage strategy, especially in marine ecosystems. In this study, we tested whether color camouflage enhances survival of the intertidal marine isopod Pentidotea (Idotea) wosnesenskii, quantified patterns of camouflage in different algal habitats, and examined how algal diet affected color change and growth using laboratory assays. In the field, isopods collected from two differently colored algal habitats (the brown alga Fucus distichus and the red alga Odonthalia floccosa) matched the color of their respective algal habitats, and also differed significantly in body size: smaller red isopods were found on red algae, while larger brown isopods were found on brown algae. Predation experiments demonstrated these color differences had fitness benefits: brown isopods that matched their brown algae habitats survived at higher rates than red unmatched isopods. Surprisingly, despite the propensity of isopods to match their algal habitats, algal diet had no effect on color change in color change experiments. Instead, isopods in all treatments turned browner, matching the color of the algal habitat that many isopods are found on as adults. In summary, our data supported our hypothesis that background matching serves an adaptive function in reducing predation, with important evolutionary implications for explaining the wide variation in color change mechanisms in idoteid isopods.

scholarly journals Whose trait is it anyways? Coevolution of joint phenotypes and genetic architecture in mutualisms

2021 ◽  
Vol 288 (1942) ◽  
pp. 20202483
Author(s):  
Anna M. O’Brien ◽  
Chandra N. Jack ◽  
Maren L. Friesen ◽  
Megan E. Frederickson
Keyword(s):  
Association Studies ◽  
Single Species ◽  
Genome Wide Association Studies ◽  
Interacting Species ◽  
Fitness Effects ◽  
Evolutionary Conflict ◽  
Fitness Consequences ◽  
Genome Wide ◽  
Fitness Benefits ◽  
Multiple Genomes

Evolutionary biologists typically envision a trait’s genetic basis and fitness effects occurring within a single species. However, traits can be determined by and have fitness consequences for interacting species, thus evolving in multiple genomes. This is especially likely in mutualisms, where species exchange fitness benefits and can associate over long periods of time. Partners may experience evolutionary conflict over the value of a multi-genomic trait, but such conflicts may be ameliorated by mutualism’s positive fitness feedbacks. Here, we develop a simulation model of a host–microbe mutualism to explore the evolution of a multi-genomic trait. Coevolutionary outcomes depend on whether hosts and microbes have similar or different optimal trait values, strengths of selection and fitness feedbacks. We show that genome-wide association studies can map joint traits to loci in multiple genomes and describe how fitness conflict and fitness feedback generate different multi-genomic architectures with distinct signals around segregating loci. Partner fitnesses can be positively correlated even when partners are in conflict over the value of a multi-genomic trait, and conflict can generate strong mutualistic dependency. While fitness alignment facilitates rapid adaptation to a new optimum, conflict maintains genetic variation and evolvability, with implications for applied microbiome science.

scholarly journals The Role of the Immune System from an Evolutionary Perspective

2019 ◽  
pp. 198-209
Author(s):  
Carsten Schradin ◽  
Rainer H. Straub
Keyword(s):  
Evolutionary Medicine ◽  
Future Generations ◽  
Lifetime Reproductive Success ◽  
Life History Stage ◽  
Evolutionary Perspective ◽  
Lifetime Fitness ◽  
Fitness Consequences ◽  
Reproductive Life ◽  
Fitness Benefits

“Nothing in Biology makes sense, except in the light of evolution.” This famous citation of Theodosius Dobzhansky also underlies the integrative field of evolutionary medicine, which faces the challenge to combine (patho-)physiological mechanisms with evolutionary function. Here we introduce a concept from the study of animal behavior, which are the four questions of Tinbergen that consider: 1. the ontogeny of an individual describing its development, 2. its physiological machinery, which 3. has fitness consequences influencing 4. the evolutionary history (phylogeny) of future generations. It is shown how this concept can be applied to infectious disease and to chronic inflammatory systemic diseases. Evolutionary medicine takes lifetime reproductive success into account. The hypothesis to be tested is that mechanisms underlying a disease in old age might have higher fitness benefits in the pre-reproductive and/or reproductive life history stage, leading to an overall increased lifetime fitness.

scholarly journals Evolutionary significance of maternal kinship in a long-lived mammal

2019 ◽  
Vol 374 (1780) ◽  
pp. 20180067 ◽  
Author(s):  
Emily C. Lynch ◽  
Virpi Lummaa ◽  
Win Htut ◽  
Mirkka Lahdenperä
Keyword(s):  
Social Relationships ◽  
Young Female ◽  
Evolution Of Cooperation ◽  
Evolutionary Significance ◽  
Preferential Treatment ◽  
Female Reproduction ◽  
Life History Data ◽  
Social Species ◽  
Fitness Consequences ◽  
Fitness Benefits

Preferential treatment of kin is widespread across social species and is considered a central prerequisite to the evolution of cooperation through kin selection. Though it is well known that, among most social mammals, females will remain within their natal group and often bias social behaviour towards female maternal kin, less is known about the fitness consequences of these relationships. We test the fitness benefits of living with maternal sisters, measured by age-specific female reproduction, using an unusually large database of a semi-captive Asian elephant ( Elephas maximus ) population. This study system is particularly valuable to an exploration of reproductive trends in a long-lived mammal, because it includes life-history data that span multiple generations, enabling a study of the effects of kinship across a female's lifespan. We find that living near a sister significantly increased the likelihood of annual reproduction among young female elephants, and this effect was strongest when living near a sister 0–5 years younger. Our results show that fitness benefits gained from relationships with kin are age-specific, establish the basis necessary for the formation and maintenance of close social relationships with female kin, and highlight the adaptive importance of matriliny in a long-lived mammal. This article is part of the theme issue ‘The evolution of female-biased kinship in humans and other mammals'.

scholarly journals Exploitative leaders incite intergroup warfare in a social mammal

2020 ◽  
Vol 117 (47) ◽  
pp. 29759-29766 ◽  
Author(s):  
Rufus A. Johnstone ◽  
Michael A. Cant ◽  
Dominic Cram ◽  
Faye J. Thompson
Keyword(s):  
Female Group ◽  
Negative Consequences ◽  
Fitness Consequences ◽  
Model Predictions ◽  
Group Members ◽  
Mean Fitness ◽  
Fitness Benefits ◽  
Intergroup Conflicts ◽  
Term Data

Collective conflicts among humans are widespread, although often highly destructive. A classic explanation for the prevalence of such warfare in some human societies is leadership by self-serving individuals that reap the benefits of conflict while other members of society pay the costs. Here, we show that leadership of this kind can also explain the evolution of collective violence in certain animal societies. We first extend the classic hawk−dove model of the evolution of animal aggression to consider cases in which a subset of individuals within each group may initiate fights in which all group members become involved. We show that leadership of this kind, when combined with inequalities in the payoffs of fighting, can lead to the evolution of severe intergroup aggression, with negative consequences for population mean fitness. We test our model using long-term data from wild banded mongooses, a species characterized by frequent intergroup conflicts that have very different fitness consequences for male and female group members. The data show that aggressive encounters between groups are initiated by females, who gain fitness benefits from mating with extragroup males in the midst of battle, whereas the costs of fighting are borne chiefly by males. In line with the model predictions, the result is unusually severe levels of intergroup violence. Our findings suggest that the decoupling of leaders from the costs that they incite amplifies the destructive nature of intergroup conflict.

The control of color change in the Pacific tree frog, Hyla regilla

2004 ◽  
Vol 82 (6) ◽  
pp. 889-896 ◽  
Author(s):  
James C Stegen ◽  
C M Gienger ◽  
Lixing Sun
Keyword(s):  
Light Intensity ◽  
Environmental Variables ◽  
Color Change ◽  
Interactive Effects ◽  
Tree Frog ◽  
Background Color ◽  
Hyla Regilla ◽  
Background Matching ◽  
The Pacific ◽  
Initial Color

A number of environmental variables have been identified as affecting anuran color, but rarely have the interactions between these variables been investigated. In attempt to elucidate the function of color change, we conducted a within-subject, full factorial experiment designed to determine the simple and interactive effects of background, temperature, and light intensity on the rate of color change in the Pacific tree frog (Hyla regilla Baird and Girard, 1852). Color was investigated holistically, as well as by decomposing it into its constituent parts (hue, chroma, and lightness), using digital photography. The rate of color change was faster on the green versus the brown background, at 10 versus 25 °C, and at low versus high light intensity. There was also a significant effect of the interaction between background color and temperature on the rate of color change. We found increased rates of hue, chroma, lightness, and color change with increasing initial hue, chroma, lightness, and color distances between the Pacific tree frog and its background, respectively. In addition, initial color distance covaried with changes in environmental variables. After controlling for initial color distance, and thus the effects of background matching, background color and temperature still showed a significant interaction for their effects on rate of color change. These results suggest that crypsis (i.e., background matching) is not the only function of physiological color change in H. regilla. Physiological color change may also be used to hydro- and (or) thermo-regulate.

Color Change Mechanisms of Cold-Blooded Vertebrates

Copeia ◽  
1964 ◽  
Vol 1964 (1) ◽  
pp. 247 ◽  
Author(s):  
Aubrey Gorbman ◽  
H. Waring
Keyword(s):  
Color Change ◽  
Change Mechanisms

scholarly journals Thermal Diffusivity, Moisture Diffusivity, and Color Change of Codonopsis javanica with the Support of the Ultrasound for Drying

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Xuan-Quang Nguyen ◽  
Anh-Duc Le ◽  
Ngoc-Phuong Nguyen ◽  
Hay Nguyen
Keyword(s):  
Thermal Diffusion ◽  
Color Change ◽  
Theoretical Calculations ◽  
Moisture Diffusion ◽  
Pso Algorithm ◽  
Moisture Diffusivity ◽  
Air Temperatures ◽  
Ultrasonic Technology ◽  
Color Differences

In this study, drying kinetics, including thermal and moisture, of Codonopsis javanica with the support of ultrasonic technology in the drying process were investigated. Experimental processes were carried out at drying air temperatures of 40°C, 45°C, and 50°C with and without ultrasound at a frequency of 20 kHz and three levels of intensity: 1.3 kW/m2, 1.8 kW/m2, and 2.2 kW/m2. Based on theoretical calculations, experimental data, and the particle swarm optimization (PSO) algorithm, the coefficient of thermal diffusion was determined in the range of 1.01–1.36 × 10−7 m2/s, and the coefficient of moisture diffusion is in the range of 3.2–6.7 × 10−10 m2/s. In addition, the color parameters (L∗, a∗, and b∗) of the drying materials were also considered. Results showed the overall color differences (∆E) of dried products change in the range of 8.0–12.9 compared with the fresh ones. In this work, the multiple boundary conditions were considered to determine the moisture and thermal diffusion coefficients; the results obtained prove that the quality of dried products in terms of color change is also improved.

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