Fighting success in relation to body mass and drumming activity in the male wolf spider Hygrolycosa rubrofasciata

1997 ◽  
Vol 75 (9) ◽  
pp. 1532-1535 ◽  
Author(s):  
Janne Kotiaho ◽  
Rauno V. Alatalo ◽  
Johanna Mappes ◽  
Silja Parri
Keyword(s):  
Sexual Selection ◽  
Body Mass ◽  
Wolf Spider ◽  
Male Body ◽  
Male Courtship ◽  
Hygrolycosa Rubrofasciata ◽  
Males And Females ◽  
A Minor ◽  
Selection Of ◽  
Agonistic Encounters

In the wolf spider Hygrolycosa rubrofasciata, males court females by drumming dry leaves with their abdomen. Females prefer to mate with the most actively drumming males, and courtship drumming activity is also positively correlated with male viability. However, body mass of the males seems to have only a minor, if any, effect on female choice or male viability. There is also no correlation between male body mass and courtship drumming activity. We studied the effect of body mass and courtship drumming activity on the outcome of agonistic encounters between male H. rubrofasciata. For this purpose, males and females were randomly placed in a plastic arena, where male courtship drumming activity and agonistic encounters were recorded. Large differences in body mass and drumming activity between two rivals seemed to independently increase the probability of the larger or more active males winning. We conclude that while courtship drumming activity affects the fighting success of the males, and body mass more so, male–male interactions may not be of major importance in sexual selection of H. rubrofasciata.

Assessing the intensity of sexual selection on male body mass and antler length in roe deer Capreolus capreolus: is bigger better in a weakly dimorphic species?

Oikos ◽  
2010 ◽  
Vol 119 (9) ◽  
pp. 1484-1492 ◽  
Author(s):  
Cécile Vanpé ◽  
Jean-Michel Gaillard ◽  
Petter Kjellander ◽  
Olof Liberg ◽  
Daniel Delorme ◽  
...  
Keyword(s):  
Sexual Selection ◽  
Body Mass ◽  
Roe Deer ◽  
Capreolus Capreolus ◽  
Male Body ◽  
Dimorphic Species

1. Darwin’s other big idea

2018 ◽  
pp. 1-15 ◽  
Author(s):  
Leigh W. Simmons
Keyword(s):  
Sexual Selection ◽  
Female Choice ◽  
Egg Production ◽  
Sexual Differences ◽  
The Other ◽  
Sexual Competition ◽  
Sexual Characteristics ◽  
Sexual Selection Theory ◽  
Males And Females ◽  
Selection Of

The idea that males and females often look, sound, smell, and behave differently is uncontroversial. Where those differences came from, however, and what role they play in various species—including humans—is not. ‘Darwin’s other big idea’ outlines Charles Darwin’s sexual selection theory: differential reproduction based on sexual competition, whether between the members of one sex for access to the other, or by selection of particular mating partners. Differences in reproductive parts directly involved in sperm or egg production—primary sexual characteristics—were relatively easy to explain. The other kinds of sexual differences, he proposed, could evolve in one of two ways: male–male competition resulting in weapons, or female choice resulting in ornaments, but this was highly controversial.

scholarly journals A Phylogenetic Perspective on the Evolution of Chromatic Ultraviolet Plumage Coloration in Grackles and Allies (Icteridae)

The Auk ◽  
2006 ◽  
Vol 123 (1) ◽  
pp. 211-234 ◽  
Author(s):  
Muir D. Eaton
Keyword(s):  
Sexual Selection ◽  
Large Body ◽  
Plumage Coloration ◽  
Behavioral Studies ◽  
Evolutionary Force ◽  
Evolutionary Changes ◽  
Phylogenetic Perspective ◽  
Males And Females ◽  
Museum Study ◽  
Selection Of

Abstract Plumage traits have been studied intensely for more than a century, especially bright and exaggerated plumage. A large body of evidence across a range of avian taxa supports sexual selection as a major evolutionary force acting on plumage colors. The discovery of ultraviolet (UV) coloration in avian plumage resulted in the extension of sexual selection hypotheses to explain the evolution of potential UV plumage traits. However, there have been no comparative evolutionary studies elucidating the origin of UV signals in birds. Here, I used a comparative phylogenetic approach to investigate the evolution of chromatic UV plumage colors in the grackles-and-allies clade of the New World blackbirds (Icteridae). On the basis of reflectance data collected from museum study skins, I have determined that UV plumage signals have evolved multiple times from an ancestral condition that lacked UV plumage signals, with very few unambiguous reversals. Although UV plumage has evolved in both males and females, there have been significantly more evolutionary changes in male UV plumage characters. Concentrated changes tests and correlations of independent contrasts reveal evidence for sexual selection of some male UV plumage characters, as well as an increase in UV plumage coloration for species found in open habitats. These results support the use of objective assessments of avian colors (i.e. spectrophotometry) to properly interpret patterns of plumage evolution generally, and they suggest the need for behavioral studies on the function of chromatic UV signals in several blackbird species. Una Perspectiva Filogenética sobre la Evolución de la Coloración Ultravioleta en los Changos y Chamones (Icteridae)

scholarly journals Analysis of the Association Between Motor and Anthropometric Variables with Change of Direction Speed and Reactive Agility Performance

2015 ◽  
Vol 47 (1) ◽  
pp. 137-145 ◽  
Author(s):  
Tine Sattler ◽  
Damir Sekulić ◽  
Miodrag Spasić ◽  
Mia Perić ◽  
Ante Krolo ◽  
...  
Keyword(s):  
Body Mass ◽  
Body Height ◽  
Male Body ◽  
College Level ◽  
F Test ◽  
Change Of Direction ◽  
Stop And Go ◽  
Significant Difference ◽  
Reactive Agility ◽  
Males And Females

AbstractThere is an evident lack of studies examining the factors associated with reactive agility performances. The aim of this study was to evaluate the association between anthropometrics, body composition, jumping capacity, reactive strength, and balance with a stop-and-go change of direction speed (CODS) and reactive agility. The total sample comprised 39 male (body height: 182.95 ± 5.19 cm; body mass: 80.66 ± 7.69 kg) and 34 female (body height: 171.45 ± 6.81 cm; body mass: 61.95 ± 6.70 kg) college-level athletes (21.9 ± 1.9 years of age). The variables included body height, body mass, the percentage of body fat (BF%), balance as measured by an overall-stability index, the countermovement jump (CMJ), a reactive-strength index (RSI), stop-and-go reactive agility, and stop-and-go CODS. To define the associations between motor and anthropometric variables with CODS and reactive agility, the participants were clustered into three achievement groups based on their CODS and reactive agility performances. The ANOVA showed a significant difference between the CODS-based achievement groups for the CMJ (F test = 3.45 and 3.60 for males and females, respectively; p < 0.05), the RSI (F test = 6.94 and 5.29 for males and females, respectively; p < 0.05), and balance (F test = 3.47; p < 0.05 for males). In females, the reactive agility achievement groups differed significantly in the RSI (F test = 6.46; p < 0.05), the CMJ (F test = 4.35; p < 0.05) and BF% (F test = 4.07; p < 0.05), which is further confirmed by discriminant canonical analysis (Can R = 0.74; p < 0.05). The results confirm the need for independent evaluation and training for both CODS and reactive agility performance in sports.

Overwintering survival in relation to body mass in a field population of the wolf spider (Hygrolycosa rubrofasciata)

1999 ◽  
Vol 248 (2) ◽  
pp. 270-272 ◽  
Author(s):  
Janne S. Kotiaho ◽  
Rauno V. Alatalo ◽  
Johanna Mappes ◽  
Silja Parri
Keyword(s):  
Body Mass ◽  
Wolf Spider ◽  
Field Population ◽  
Hygrolycosa Rubrofasciata ◽  
Overwintering Survival

scholarly journals Hyoid Bone Size and Its Implications for Social Organization and Sexual Selection in Alouatta pigra and the Elusive Alouatta macconnelli

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Aubrey R. Whittaker ◽  
Shawn Lehman
Keyword(s):  
Sexual Selection ◽  
Social Organization ◽  
Null Hypothesis ◽  
Hyoid Bone ◽  
Selection Process ◽  
Alouatta Pigra ◽  
Royal Ontario Museum ◽  
The Social ◽  
Males And Females ◽  
Selection Of

The purpose of this research paper is focusing on the hyoid bone in Alouatta pigra and Alouatta macconnelli and determine its role in affecting the social organization and sexual selection of the individuals in these species. This includes the discussion on the dimensions of the hyoid between the males and females as well as an analysis of observed social behaviour patterns and the sexual selection process. It was found that female Alouatta pigra had a larger hyoid than males of the species and that Alouatta macconnelli males had a hyoid nearly twice the size of females. The hyoids were measured from the Mammal Biodiversity collection at the Royal Ontario Museum. The bones dimensions were taken using plastic calipers and their circumference measured using a soft tape measure. Based on the sexual selection and social organisation of Alouatta pigra which is multi-male/multi-female with the occasional unimale with multiple females, the null hypothesis must be accepted as the larger hyoid is not found in males but in females and the size of the hyoid does not affect the social organization in this species. In Alouatta macconnelli, there is little information on this species but the null hypothesis is rejected as males have much larger hyoids than females and the social organization is that of a uni-male with multiple females.

Potential mechanisms of phenotypic divergence in body size between Newfoundland and mainland black bear populations

2001 ◽  
Vol 79 (9) ◽  
pp. 1650-1660 ◽  
Author(s):  
Shane P Mahoney ◽  
John A Virgl ◽  
Kim Mawhinney
Keyword(s):  
Sexual Selection ◽  
Body Size ◽  
Body Mass ◽  
Sexual Size Dimorphism ◽  
Large Body ◽  
Black Bear ◽  
Relative Difference ◽  
Black Bears ◽  
Male Body ◽  
Size Dimorphism

Phenotypic variation in body size and degree of sexual size dimorphism of North American black bears (Ursus americanus) was quantified for populations from New Brunswick, Quebec, Ontario, Maine, Alaska, and the island of Newfoundland. Based on a model of island biogeography developed by Case, we predicted that body size should be larger in Newfoundland bears than in mainland populations. The presence of few large predators and minimal competition between herbivore prey on Newfoundland allow an appropriate test of the model (i.e., food availability for bears may differ between populations on the mainland and in Newfoundland). In addition, sexual-selection theory predicts that the coevolution of polygyny and large size will be coupled with an increase in sexual size dimorphism. Therefore, we also predicted that among the six populations, male body mass should scale hyperallometrically with female body mass (i.e., slope > 1). Analysis of deterministic growth curves indicated that bears from Newfoundland attained greater asymptotic body size than populations on the mainland, which supports our first prediction. On average, the relative difference in asymptotic body mass between females from the island and mainland populations was 55%, while the relative difference between males was 37%. However, we found that sexual size dimorphism did not increase disproportionately with body mass among the six populations, which refuted our second prediction. We discuss a range of abiotic and biotic selection pressures possibly responsible for larger body size in Newfoundland bears. We suggest that the ability to exploit seasonally abundant and spatially dispersed dietary protein by female and male black bears on the island has been and is still a primary environmental factor selecting for large body size in Newfoundland bears. Although the relationship between sexual size dimorphism and body size is tenuous (slope [Formula: see text] 1), it does suggest that (an)other adaptive mechanism(s), opposing sexual selection for extreme male size, explain(s) a large amount of the variation in sexual size dimorphism among black bear populations.

scholarly journals Divergent selection on behavioral and chemical traits contributes to isolation between populations of Drosophila melanogaster

2020 ◽  
Author(s):  
Bozhou Jin ◽  
Daniel A. Barbash ◽  
Dean M Castillo
Keyword(s):  
Sexual Selection ◽  
Reproductive Isolation ◽  
Cuticular Hydrocarbons ◽  
Male Courtship ◽  
Multiple Traits ◽  
Selection Gradients ◽  
Female Genotype ◽  
Rapid Diversification ◽  
Males And Females ◽  
Chemical Traits

AbstractSpeciation is driven by traits that can act to prohibit mating between nascent lineages, including male courtship and female preference for male traits. Mating barriers involving these traits evolve quickly because there is strong selection on males and females to maximize reproductive success, and the tight co-evolution of mating interactions can lead to rapid diversification of sexual behavior. Using lineages of D. melanogaster that show strong asymmetrical reproductive isolation, we ask two key questions: which specific male traits are females selecting, and are these traits under divergent sexual selection? These questions have proven extremely challenging to answer, because even in closely related lineages males often differ in multiple traits related to mating behavior. We address these questions by estimating selection gradients for male courtship and cuticular hydrocarbons for two different female genotypes. We identify specific behaviors and particular cuticular hydrocarbons that are under divergent sexual selection and likely contribute to reproductive isolation. Additionally, we discovered that a subset of these traits are plastic; males adjust these traits based on the identity of the female genotype they interact with. These results suggest that even when male courtship is not fixed between lineages, ongoing selection can contribute to reproductive isolation.

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