Natural and sexual selection shape the evolution of colour and conspicuousness in North American wood-warblers (Parulidae)

2020 ◽  
Vol 130 (1) ◽  
pp. 89-100 ◽  
Author(s):  
Richard K Simpson ◽  
Allison F Mistakidis ◽  
Stéphanie M Doucet
Keyword(s):  
Sexual Selection ◽  
Environmental Variation ◽  
Upper Body ◽  
Body Regions ◽  
Visual Models ◽  
Wood Warblers ◽  
Visual Background ◽  
Selective Forces ◽  
Natural And Sexual Selection ◽  
Female Coloration

Abstract Natural and sexual selection drive colour evolution in animals. However, these different selective forces are often studied independently or without considering environmental variation. We evaluated the roles of natural and sexual selection together on colour evolution in 15 sympatric wood-warbler species, while considering the influence of variation in the light environment and visual background. We tested the influence of each selective pressure on male and female coloration and contrast against the background using avian visual models in phylogenetically controlled analyses. We found natural and sexual selection simultaneously driving cryptic and conspicuous plumage in males by acting on different body regions. For example, we found that ground-nesting species had males with conspicuous under-body plumage and cryptic upper-body plumage, showing how natural and sexual selection can drive colour evolution concordantly. We also found interesting relationships with female plumage, such as nest predation positively covarying with female contrast against the background, suggesting a cost to female conspicuousness. Our findings here showcase the complexity of selection on coloration and illustrate the importance of: (1) accounting for environmental variation when assessing how natural and sexual selection drive colour evolution; and (2) testing how multiple selection pressures are shaping colour diversity among species.

scholarly journals Migration and the evolution of sexual dichromatism: evolutionary loss of female coloration with migration among wood-warblers

2015 ◽  
Vol 282 (1809) ◽  
pp. 20150375 ◽  
Author(s):  
Richard K. Simpson ◽  
Michele A. Johnson ◽  
Troy G. Murphy
Keyword(s):  
Sexual Selection ◽  
Sexual Dichromatism ◽  
Ancestral State ◽  
Migration Distance ◽  
Female Ornamentation ◽  
Wood Warblers ◽  
Selection For ◽  
Evolution Of Migration ◽  
And Migration ◽  
Female Coloration

The mechanisms underlying evolutionary changes in sexual dimorphism have long been of interest to biologists. A striking gradient in sexual dichromatism exists among songbirds in North America, including the wood-warblers (Parulidae): males are generally more colourful than females at northern latitudes, while the sexes are similarly ornamented at lower latitudes. We use phylogenetically controlled comparative analysis to test three non-mutually exclusive hypotheses for the evolution of sexual dichromatism among wood-warblers. The first two hypotheses focus on the loss of female coloration with the evolution of migration, either owing to the costs imposed by visual predators during migration, or owing to the relaxation of selection for female social signalling at higher latitudes. The third hypothesis focuses on whether sexual dichromatism evolved owing to changes in male ornamentation as the strength of sexual selection increases with breeding latitude. To test these hypotheses, we compared sexual dichromatism to three variables: the presence of migration, migration distance, and breeding latitude. We found that the presence of migration and migration distance were both positively correlated with sexual dichromatism, but models including breeding latitude alone were not strongly supported. Ancestral state reconstruction supports the hypothesis that the ancestral wood-warblers were monochromatic, with both colourful males and females. Combined, these results are consistent with the hypotheses that the evolution of migration is associated with the relaxation of selection for social signalling among females and that there are increased predatory costs along longer migratory routes for colourful females. These results suggest that loss of female ornamentation can be a driver of sexual dichromatism and that social or natural selection may be a stronger contributor to variation in dichromatism than sexual selection.

scholarly journals Colour variation of the Maltese wall lizards (Podarcis filfolensis) at population and individual levels in the Linosa island

2021 ◽  
Author(s):  
Roberto Sacchi ◽  
Stefano Scali ◽  
Marco Mangiacotti ◽  
Davide Ruffo
Keyword(s):  
Sexual Selection ◽  
Trade Off ◽  
Colour Variation ◽  
Avian Predators ◽  
Body Regions ◽  
Animal Colouration ◽  
Different Populations ◽  
Males And Females ◽  
Natural And Sexual Selection ◽  
Different Levels

AbstractThe research on animal colouration has always been of great interest for biologists but since the last decades it has grown exponentially thanks to multidisciplinary approaches. Animals have found several ways to deal with the camouflage/communication trade-off in colouration, leading to the evolution of alternative patterns of variation of colourations at different levels including signal partitioning and spatial resolution of colouration. In this paper we analyse the variability of dorsal and ventral colouration in males and females of Maltese wall lizards in three populations on Linosa. We collected high-resolution digital images of dorsal, ventral and throat colouration from 61 lizards (32 males and 29 females). We showed that the colouration differs among sexes and body regions within the same individual. Colourations are also variable among individuals within population, as well as among different populations across the Island. Finally, we detected a lizard’s colouration shifts with increasing body size. Those result supports the hypothesis that colouration in this species evolved under the competing pressures of natural and sexual selection to promote signals that are visible to conspecifics while being less perceptible to avian predators. Graphic abstract

scholarly journals The physical environment mediates male harm and its effect on selection in females

2017 ◽  
Vol 284 (1858) ◽  
pp. 20170424 ◽  
Author(s):  
Li Yun ◽  
Patrick J. Chen ◽  
Amardeep Singh ◽  
Aneil F. Agrawal ◽  
Howard D. Rundle
Keyword(s):  
Drosophila Melanogaster ◽  
Sexual Selection ◽  
Physical Environment ◽  
Selective Advantage ◽  
Laboratory Studies ◽  
Male Choice ◽  
Female Fitness ◽  
High Quality ◽  
Evolutionary Consequences ◽  
Natural And Sexual Selection

Recent experiments indicate that male preferential harassment of high-quality females reduces the variance in female fitness, thereby weakening natural selection through females and hampering adaptation and purging. We propose that this phenomenon, which results from a combination of male choice and male-induced harm, should be mediated by the physical environment in which intersexual interactions occur. Using Drosophila melanogaster , we examined intersexual interactions in small and simple (standard fly vials) versus slightly more realistic (small cages with spatial structure) environments. We show that in these more realistic environments, sexual interactions are less frequent, are no longer biased towards high-quality females, and that overall male harm is reduced. Next, we examine the selective advantage of high- over low-quality females while manipulating the opportunity for male choice. Male choice weakens the viability advantage of high-quality females in the simple environment, consistent with previous work, but strengthens selection on females in the more realistic environment. Laboratory studies in simple environments have strongly shaped our understanding of sexual conflict but may provide biased insight. Our results suggest that the physical environment plays a key role in the evolutionary consequences of sexual interactions and ultimately the alignment of natural and sexual selection.

The New Synthesis

2018 ◽  
pp. 235-245
Author(s):  
Erika Lorraine Milam
Keyword(s):  
Sexual Selection ◽  
Information Processing ◽  
Human Nature ◽  
Genetic Information ◽  
Next Generation ◽  
New Synthesis ◽  
Genetic Information Processing ◽  
The 1960S ◽  
Natural And Sexual Selection

This chapter discusses new understandings of humanity from the 1960s onward. It shows how a particular group of scientists struggled with the question of human nature by conceiving of natural and sexual selection as acting at the level of individuals, who in turn served as genetic-information processing units. A trait could not spread in a population unless it conferred some advantage to the individuals who possessed it, allowing them to contribute more copies of their genes to the next generation of that population than other individuals. These struggles are furthermore framed within a period when sociobiology was just starting to get a foothold in academics.

Principles of evolutionary theory, evolutionary psychopathology, and genetics

2015 ◽  
pp. 3-40
Author(s):  
Martin Brüne
Keyword(s):  
Sexual Selection ◽  
Human Brain ◽  
Psychosomatic Medicine ◽  
Genetic Variants ◽  
Driving Force ◽  
Human Cognition ◽  
Protective Effects ◽  
Changing Environments ◽  
Genes And Environment ◽  
Natural And Sexual Selection

Darwin’s work on evolution by natural and sexual selection is the central scientific framework in biology that explains how life developed through adaptation to changing environments. Evolution has been the driving force that has shaped the human brain and mind in the same way as it has formed somatic traits. Many adaptations pertaining to human cognition, emotions, and behaviour emerged in ancestral environments of evolutionary adaptedness, from which modern living conditions deviate in one way or another. Such ‘mismatches’ of evolved traits and current environments may cause vulnerability to dysfunctional operation of cognitive, emotional, and behavioural traits. Genes and environment interact in manifold ways, yet genetic plasticity may not only convey vulnerability to dysfunction. Instead, the very same genetic variants that may lead to dysfunction when associated with environmental adversity exert protective effects against dysfunction when environments are more favourable. These insights have yet to be acknowledged by psychiatry and psychosomatic medicine.

Sign in / Sign up

Export Citation Format

Share Document