328 results on '"mutual sexual selection"'
Search Results
2. Contrasting Mutual Sexual Selection on Homologous Signal Traits in Drosophila serrata
- Author
-
Chenoweth, Stephen F. and Blows, Mark W.
- Published
- 2005
- Full Text
- View/download PDF
3. Comparing Complex Fitness Surfaces: Among‐Population Variation in Mutual Sexual Selection inDrosophila serrata
- Author
-
Howard D. Rundle, Mark W. Blows, and Stephen F. Chenoweth
- Subjects
Male ,Sympatry ,Sex Characteristics ,Multivariate statistics ,education.field_of_study ,Fitness landscape ,Population ,Biology ,biology.organism_classification ,Hydrocarbons ,Evolutionary biology ,Drosophilidae ,Sexual selection ,Animals ,Drosophila ,Female ,Genetic Fitness ,Selection, Genetic ,education ,Ecology, Evolution, Behavior and Systematics ,Selection (genetic algorithm) - Abstract
Despite a dramatic increase in empirical estimates of phenotypic selection over the past two decades, we remain remarkably ignorant about variation in the multivariate fitness surfaces that shape the adaptive landscape. We develop a novel approach for quantifying patterns of spatial and/or temporal variation in multivariate selection that directly compares vectors of linear selection gradients (beta) and matrices of nonlinear selection gradients (gamma) that describe the multivariate fitness surface in each population. We apply this approach to estimates of sexual selection on a suite of cuticular hydrocarbons (CHCs) in males and females from nine geographic populations of Drosophila serrata. In males, variation in linear sexual selection was associated with the presence of the related species Drosophila birchii, suggesting that female mate preferences for male CHCs differ between sympatry and allopatry. This is consistent with previous experimental results suggesting that reproductive character displacement of male CHCs has resulted from selection caused by the presence of D. birchii. No significant associations were found for nonlinear sexual selection in males. In females, large-scale variation in both linear and nonlinear sexual selection was negatively associated with assumed-neutral population genetic structure, suggesting a key role for chance events in male mate preference divergence.
- Published
- 2008
4. Signal trait sexual dimorphism and mutual sexual selection in Drosophila serrata
- Author
-
Chenoweth, Stephen F. and Blows, Mark W.
- Subjects
Drosophila -- Research ,Sexual selection in animals -- Research ,Dimorphism (Biology) -- Research ,Biological sciences - Abstract
The evolution of sexual dimorphism may occur when natural and sexual selection result in different optimum trait values for males and females. The intersex genetic correlations and the relative strength of sexual selection on males and females are simultaneously measured, for a set of cuticular hydrocarbons in Drosophila serrata.
- Published
- 2003
5. Contrasting Mutual Sexual Selection on Homologous Signal Traits in Drosophila serrata
- Author
-
Mark W. Blows and Stephen F. Chenoweth
- Subjects
Male ,Genetics ,education.field_of_study ,Natural selection ,Population ,Biology ,Hydrocarbons ,Mating preferences ,Drosophila serrata ,Sexual dimorphism ,Sexual Behavior, Animal ,Phenotype ,Sex Factors ,Evolutionary biology ,Sexual selection ,Homologous chromosome ,Animals ,Drosophila ,Female ,education ,Ecology, Evolution, Behavior and Systematics ,Selection (genetic algorithm) - Abstract
The nature of male mating preferences, and how they differ from female mating preferences in species with conventional sex roles, has received little attention in sexual selection studies. We estimated the form and strength of sexual selection as a consequence of male and female mating preferences in a laboratory-based population of Drosophila serrata. The differences between sexual selection on male and female signal traits (cuticular hydrocarbons [CHCs]) were evaluated within a formal framework of linear and nonlinear selection gradients. Females tended to exert linear sexual selection on male CHCs, whereas males preferred intermediate female CHC phenotypes leading to convex (stabilizing) selection gradients. Possible mechanisms determining the nonlinear nature of sexual selection on female CHCs are proposed.
- Published
- 2005
6. Signal trait sexual dimorphism and mutual sexual selection in Drosophila serrata
- Author
-
Stephen F. Chenoweth and Mark W. Blows
- Subjects
Male ,Sex Characteristics ,Natural selection ,Secondary sex characteristic ,Biology ,Genetic correlation ,Biological Evolution ,Sexual dimorphism ,Sexual Behavior, Animal ,Evolutionary biology ,Sexual selection ,Genetics ,Trait ,Sexual maturity ,Animals ,Drosophila ,Female ,Selection, Genetic ,Sex Attractants ,General Agricultural and Biological Sciences ,Ecology, Evolution, Behavior and Systematics ,Sex linkage - Abstract
The evolution of sexual dimorphism may occur when natural and sexual selection result in different optimum trait values for males and females. Perhaps the most prominent examples of sexual dimorphism occur in sexually selected traits, for which males usually display exaggerated trait levels, while females may show reduced expression of the trait. In some species, females also exhibit secondary sexual traits that may either be a consequence of a correlated response to sexual selection on males or direct sexual selection for female secondary sexual traits. In this experiment, we simultaneously measure the intersex genetic correlations and the relative strength of sexual selection on males and females for a set of cuticular hydrocarbons in Drosophila serrata. There was significant directional sexual selection on both male and female cuticular hydrocarbons: the strength of sexual selection did not differ among the sexes but males and females preferred different cuticular hydrocarbons. In contrast with many previous studies of sexual dimorphism, intersex genetic correlations were low. The evolution of sexual dimorphism in D. serrata appears to have been achieved by sex-limited expression of traits controlled by genes on the X chromosome and is likely to be in its final stages.
- Published
- 2003
7. Comparing Complex Fitness Surfaces: Among‐Population Variation in Mutual Sexual Selection inDrosophila serrata
- Author
-
Rundle, Howard D., primary, Chenoweth, Stephen F., additional, and Blows, Mark W., additional
- Published
- 2008
- Full Text
- View/download PDF
8. Mutual sexual selection in a monogamous seabird
- Author
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Jones, Ian L. and Hunter, Fiona M.
- Subjects
Auks -- Sexual behavior ,Sexual selection in animals -- Research ,Cage birds -- Research ,Environmental issues ,Science and technology ,Zoology and wildlife conservation - Abstract
The sexual responses of the monogamous seabird Asthea cristatella or crested auklet were studied to test the effects of ornamental traits on the mating preferences of this species. The responses of male and female auklets on opposite-sex models with shortened and lengthened crest ornaments were observed. Results show that both males and females exhibited more sexual displays to a prospect with an accentuated (lengthened) crest. This confirms Darwin's theory that mutual sexual selection fuels the evolution of ornaments in monogamous sexually monomorphic animals.
- Published
- 1993
9. Mutual sexual selection in a monogamous seabird
- Author
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Fiona M. Hunter and Ian L. Jones
- Subjects
Multidisciplinary ,biology ,Mate choice ,Sexual selection ,biology.animal ,Cristatella ,Zoology ,Ornaments ,Seabird ,biology.organism_classification ,Natural variation ,Crested auklet ,Mating preferences - Abstract
DARWIN1 believed that elaborate ornamental traits expressed in both sexes might be favoured by mutual sexual selection driven by both female and male mate choice. Experimental studies on birds2–5 and fish6–9 have shown that male ornaments can be favoured by female mating preferences. But the concept of mutual mate choice has remained untested experimentally, although it has been supported by recent modelling10. Here we report the results of a study of mate preferences of the crested auklet Aethla cristatella, a monogamous seabird in which both sexes are ornamented. In two experiments we recorded the sexual response of male and female auklets to realistic opposite-sex models with crest ornaments experimentally shortened and lengthened within the range of natural variation. Males responded to accentuated female models with more frequent sexual displays, as did females to accentuated male models, confirming the idea that ornaments expressed in both sexes could be favoured by mutual mating preferences.
- Published
- 1993
10. SIGNAL TRAIT SEXUAL DIMORPHISM AND MUTUAL SEXUAL SELECTION IN DROSOPHILA SERRATA
- Author
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Steve Chenoweth and Mark Blows
- Subjects
Genetics ,General Agricultural and Biological Sciences ,Ecology, Evolution, Behavior and Systematics - Published
- 2003
11. Experimental evidence for female mate choice in a noctuid moth
- Author
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Michiel P. van Wijk, Coby Schal, Naomi L. Zweerus, Astrid T. Groot, and Evolutionary and Population Biology (IBED, FNWI)
- Subjects
MALE SCENT BRUSHES ,F LEPIDOPTERA ,media_common.quotation_subject ,Zoology ,Lepidoptera genitalia ,Courtship ,pheromone ,PHEROMONE RECEPTORS ,female mate choice ,sexual selection ,OLFACTORY RECEPTORS ,COURTSHIP BEHAVIOR ,Ecology, Evolution, Behavior and Systematics ,HELIOTHIS-VIRESCENS LEPIDOPTERA ,media_common ,Larva ,Science & Technology ,biology ,Courtship display ,fungi ,biology.organism_classification ,Mate choice ,MUTUAL SEXUAL SELECTION ,Heliothis ,TOBACCO BUDWORM ,Pheromone ,Noctuidae ,Animal Science and Zoology ,Chloridea (Helothis) virescers ,MATING-BEHAVIOR ,Life Sciences & Biomedicine ,Behavioral Sciences ,courtship behaviour ,JUVENILE-HORMONE - Abstract
Sexual signal evolution is shaped by whether only one or both sexes execute mate choice. When mate choice by both sexes is considered, the same signalling modality is generally inferred for males and females. In the noctuid moth Chloridea (Heliothis) virescens (Lepidoptera: Noctuidae), both sexes may be signallers and responders, as both emit a sex-specific pheromone. Male mate choice is based on the female sex pheromone, perceived via the antennae, and has been well documented. However, whether females choose partners and whether their choice is based on the male pheromone are unknown. Since female mate choice is expected when males vary in quality, we reared males on two different larval diets that affected their size, which correlated positively with their fitness. When given a choice, more females mated with larger than with smaller males, and these females produced more eggs and larvae. Female choice was not affected by the absolute amount or composition of the male pheromone. Moreover, we found that antennaless females mated as readily as intact females, indicating that antennal sensory input is not required for females to mate. To determine whether females make an active choice, we studied courtship behaviour in detail and observed that females determined the outcome of courtship by moving away from the male (avoidance) or by facilitating copulation with an abdominal bend (acceptance). Additionally, we discovered that tactile sensory stimuli may be involved during courtship. Because tactile interactions may mediate contact-based (chemical) communication, we also investigated putative pheromone components on moth legs, but found no differences between the sexes. Together, our study is the first comprehensive investigation of female mate choice in a heliothine moth.
- Published
- 2021
12. Conspicuousness of passerine females is associated with the nest-building behaviour of males
- Author
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Juan Moreno, José Javier Cuervo, Juan José Soler, Judith Morales, Ministerio de Economía y Competitividad (España), and European Commission
- Subjects
0106 biological sciences ,biology ,Mutual sexual selection ,European Regional Development Fund ,Correlated evolution ,010603 evolutionary biology ,01 natural sciences ,Passerine ,Nest ,Sexual selection in females ,biology.animal ,Avian nests ,Interspecific comparative analyses ,Plumage conspicuousness ,Ecology, Evolution, Behavior and Systematics ,Demography - Abstract
Factors affecting the evolution of plumage conspicuousness in females are nowadays the focus of debate, and here we explore the possibility that the conspicuousness of female plumage and male participation in nest building are associated in birds. We hypothesize that males that participate in nest building will gain higher fecundity from high-quality ornamented females, whereas ornamented females will adjust fecundity to the costly nest-building behaviour of males. Large-sized species might experience higher costs of nest building and, thus, body size should affect the scenario described above. We used information on male contribution to nest construction (yes/no), male and female conspicuousness (conspicuous or cryptic plumage) and body size of Western Palaearctic passerines. In accordance with the hypothesis, we found that female conspicuousness, in interaction with body mass, was strongly associated with male participation in nest building. For large-sized species, female conspicuousness was positively associated with male participation in nest building. Discrete analyses of correlated evolution rendered evidence of female conspicuousness determining the evolution of male contributions to nest building, with the loss of female conspicuousness occurring more frequently before the loss of male participation in nest building. We discuss possible adaptive scenarios explaining the detected evidence because of mutual sexual selection in males and females, The study was financed by the Ministerio de Economía y Competitividad MINECO (CGL2013-48193-C3-1-P, CGL2013-48193-C3-2-P, CGL2013-48193-C3-3-P and CGL2017-83103-P) and the European Regional Development Fund (FEDER)
- Published
- 2019
13. Mutual ornamentation, sexual selection, and social dominance in the black swan
- Author
-
John Gregurke, Carol Hall, Ken Kraaijeveld, Raoul A. Mulder, Jan Komdeur, and Komdeur lab
- Subjects
animal structures ,CRESTED AUKLETS ,SPARROWS PASSER-DOMESTICUS ,Zoology ,Biology ,dominance ,BARNACLE GEESE ,PARENTAL CARE ,Cygnus atratus ,mutual sexual selection ,social selection ,REPRODUCTIVE SUCCESS ,Agonistic behaviour ,symbols.heraldic_charge ,Sexual maturity ,black swans ,Ecology, Evolution, Behavior and Systematics ,PLUMAGE VARIABILITY ,Reproductive success ,Ecology ,food and beverages ,TRIUMPH CEREMONIES ,ornamentation ,signaling ,MATE CHOICE ,Mate choice ,CYGNUS-ATRATUS ,Feather ,visual_art ,Sexual selection ,visual_art.visual_art_medium ,symbols ,MALE HOUSE SPARROWS ,Animal Science and Zoology ,Paternal care - Abstract
We investigated the adaptive significance of a sexually monomorphic ornament in the black swan Cygnus atratus. Both sexes grow curled feathers on their wings (range 7‐22 curled feathers per wing), which are displayed prominently in a range of social interactions. The number of curled feathers increased until the birds reached sexual maturity (at 2 years of age) but did not vary with age thereafter. We found evidence for both sexual and social functions of the ornament. Paired, mature individuals of both sexes had higher numbers of curled feathers than unpaired, mature birds, and individuals paired assortatively with respect to curled feather number, suggesting the feathers may be involved in mutual sexual selection. More ornamented individuals were dominant in agonistic interactions with birds of the same sex and pairing status. Highly ornamented pairs were also more likely to maintain extended tenancy of preferred cygnet feeding areas, which resulted in improved offspring survival. The curled feathers thus appear to function as a signal of social dominance, which is highly correlated with reproductive success and is therefore a reliable signal of parental quality in mate choice. Key words: black swans, Cygnus atratus, dominance, mutual sexual selection, ornamentation, signaling, social selection. [Behav Ecol 15:380–389 (2004)]
- Published
- 2004
14. The evolution of mutual ornamentation
- Author
-
Femmie J. L. Kraaijeveld-Smit, Ken Kraaijeveld, and Jan Komdeur
- Subjects
media_common.quotation_subject ,MALE MATE CHOICE ,Zoology ,FINCH BILL COLOR ,Biology ,Genetic correlation ,EYED FLIES DIOPSIDAE ,Competition (biology) ,SEXUAL SELECTION ,NORTHERN CARDINALS ,mutual sexual selection ,social selection ,Empirical evidence ,REPRODUCTIVE-PERFORMANCE ,Ecology, Evolution, Behavior and Systematics ,Selection (genetic algorithm) ,FEMALE PLUMAGE COLORATION ,media_common ,INTERACTING PHENOTYPES ,mutual ornamentation ,genetic correlation ,Sexual dimorphism ,meta-analysis ,SOCIAL-DOMINANCE ,Mate choice ,Evolutionary biology ,BARN OWL ,Sexual selection ,Animal Science and Zoology ,Social status - Abstract
Many conspicuous ornamental traits in animals are expressed in both males and females. Despite this, most research has focused on sexually dimorphic ornamentation. Mutual ornamentation has often been viewed as a result of either a nonadaptive genetic correlation between the sexes or similar selection pressures in both sexes. Here, we review the theoretical underpinning and empirical evidence for these ideas. Few studies have attempted to test empirically whether a genetic correlation between the sexes can constrain the evolution of sexual dimorphism, and the results have been mixed. By contrast, there is good evidence that mutual ornaments can have a signal function in both sexes, especially in terms of mate choice. Other possible signalling functions have received little attention. Social status signalling is especially likely to be important, because competition over nonsexual resources is more balanced between the sexes than sexual competition. There is a need for experimental studies that explicitly test these hypotheses simultaneously in both sexes.
- Published
- 2007
15. The evolution of mutual ornamentation
- Subjects
INTERACTING PHENOTYPES ,mutual ornamentation ,MALE MATE CHOICE ,FINCH BILL COLOR ,genetic correlation ,EYED FLIES DIOPSIDAE ,SEXUAL SELECTION ,meta-analysis ,SOCIAL-DOMINANCE ,BARN OWL ,NORTHERN CARDINALS ,mutual sexual selection ,social selection ,REPRODUCTIVE-PERFORMANCE ,FEMALE PLUMAGE COLORATION - Abstract
Many conspicuous ornamental traits in animals are expressed in both males and females. Despite this, most research has focused on sexually dimorphic ornamentation. Mutual ornamentation has often been viewed as a result of either a nonadaptive genetic correlation between the sexes or similar selection pressures in both sexes. Here, we review the theoretical underpinning and empirical evidence for these ideas. Few studies have attempted to test empirically whether a genetic correlation between the sexes can constrain the evolution of sexual dimorphism, and the results have been mixed. By contrast, there is good evidence that mutual ornaments can have a signal function in both sexes, especially in terms of mate choice. Other possible signalling functions have received little attention. Social status signalling is especially likely to be important, because competition over nonsexual resources is more balanced between the sexes than sexual competition. There is a need for experimental studies that explicitly test these hypotheses simultaneously in both sexes.
- Published
- 2007
16. Reply to: European barn swallows use melanin pigments to color their feathers brown
- Author
-
Riccardo Stradi
- Subjects
Melanin ,avian color vision ,mutual sexual selection ,ornamentation ,plumage coloration ,reproductive performance ,Pigment ,visual_art ,Feather ,visual_art.visual_art_medium ,Zoology ,Animal Science and Zoology ,Biology ,Barn ,Ecology, Evolution, Behavior and Systematics - Published
- 2005
17. Conspicuousness of passerine females is associated with the nest-building behaviour of males
- Author
-
Ministerio de Economía y Competitividad (España), European Commission, Soler, Juan José, Morales, Judith, Cuervo, José Javier, Moreno Klemming, Juan, Ministerio de Economía y Competitividad (España), European Commission, Soler, Juan José, Morales, Judith, Cuervo, José Javier, and Moreno Klemming, Juan
- Abstract
Factors affecting the evolution of plumage conspicuousness in females are nowadays the focus of debate, and here we explore the possibility that the conspicuousness of female plumage and male participation in nest building are associated in birds. We hypothesize that males that participate in nest building will gain higher fecundity from high-quality ornamented females, whereas ornamented females will adjust fecundity to the costly nest-building behaviour of males. Large-sized species might experience higher costs of nest building and, thus, body size should affect the scenario described above. We used information on male contribution to nest construction (yes/no), male and female conspicuousness (conspicuous or cryptic plumage) and body size of Western Palaearctic passerines. In accordance with the hypothesis, we found that female conspicuousness, in interaction with body mass, was strongly associated with male participation in nest building. For large-sized species, female conspicuousness was positively associated with male participation in nest building. Discrete analyses of correlated evolution rendered evidence of female conspicuousness determining the evolution of male contributions to nest building, with the loss of female conspicuousness occurring more frequently before the loss of male participation in nest building. We discuss possible adaptive scenarios explaining the detected evidence because of mutual sexual selection in males and females
- Published
- 2019
18. Female ornamentation and directional male mate preference in the rock sparrow.
- Author
-
Griggio, Matteo, Devigili, Alessandro, Hoi, Herbert, and Pilastro, Andrea
- Subjects
- *
ANIMAL sexual behavior , *FEATHERS , *SPARROWS , *CAROTENOIDS , *SEXUAL selection , *BIRDS - Abstract
Albeit there is growing evidence that males prefer to mate with ornamented females, it has been suggested that the production of costly ornaments may reduce female fecundity, hence favoring males with a preference for females with average ornamentation. In the rock sparrow, Petronia petronia, males and females possess a sexually selected patch of yellow feathers on the breast (a carotenoid-based trait). To test whether males prefer females with the largest ornament or average ornamented females, male rock sparrows were simultaneously faced with 3 conspecific females differing in breast patch size and a female house sparrow as a control. We found that the house sparrow and rock sparrow female with the smallest patch were least preferred, and males showed a clear proximity preference for the females with the above average–sized patch. Our results demonstrate that, contrary to theoretical predictions, a directional preference for female ornament was observed. Directional male preference may arise as consequence of a male's sensory bias or may be associated with indirect (genetic) benefits of choosing ornamented females, if ornament size is correlated with female genetic quality. Clearly, more work is necessary to identify the conditions under which directional preference for female ornament arises. [ABSTRACT FROM PUBLISHER]
- Published
- 2009
- Full Text
- View/download PDF
19. Is territory defence related to plumage ornaments in the king penguin Aptenodytes patagonicus?
- Author
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Viera, Vanessa, Nolan, Paul M., Côté, Steeve D., Jouventin, Pierre, Groscolas, René, Viera, Vanessa, Nolan, Paul M., Côté, Steeve D., Jouventin, Pierre, and Groscolas, René
- Abstract
Colourful ornaments in monogamous birds may be directed at potential mates or other conspecifics to signal individual condition, reproductive status or fighting ability, especially in monogamous and territorial species. We investigated whether the size of the orange auricular patch may be an indicator of aggressiveness in the king penguin Aptenodytes patagonicus, a monogamous and territorial seabird. The relationship between auricular patch size and defence behaviour was explored relative to territory location (centre vs. periphery of the colony), period of reproduction (early vs. late), state of reproduction (incubation vs. brooding) and sex. The proportion of time spent in territorial defence and the rate of aggressive behaviours were positively correlated with auricular patch size, mainly because central birds were more aggressive than peripheral birds and also had larger patch sizes. The period of reproduction, state of reproduction and sex did not interact with patch size to affect aggressiveness. Our results suggest that the size of the auricular patch in king penguins may be a reliable signal allowing individuals to evaluate the quality of mates or competitors in terms of aggressiveness. Whether aggressiveness is directly linked to patch size or indirectly through body condition, however, remains to be determined. In any event, birds with larger patches seem to gain central territories in the colony, thereby increasing their reproductive success. Finally, our study adds to the growing evidence that the evolution of sexually monomorphic ornaments may stem from mutual sexual selection.
- Published
- 2021
20. A new toothless pterosaur from the Early Cretaceous Jehol Biota with comments on the Chaoyangopteridae.
- Author
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Wang, Xiaolin, Kellner, Alexander W. A., Jiang, Shunxing, Chen, He, Costa, Fabiana R., Cheng, Xin, Zhang, Xinjun, Nova, Bruno C. Vila, de Almeida Campos, Diogenes, Sayão, Juliana M., Rodrigues, Taissa, Bantim, Renan A. M., Saraiva, Antônio A. F., and Zhou, Zhonghe
- Subjects
BIOTIC communities ,PTEROSAURIA ,PALEOECOLOGY ,EOCENE Epoch ,EAR ,SPECIES - Abstract
The Chaoyangopteridae is a clade of azhdarchoid pterosaurs that stands out in China, particularly in the Jehol Biota, as a Cretaceous group of medium-sized and high-crested pterosaurs. Herein, we describe a new species, Meilifeilong youhao gen. et sp. nov., based on two specimens, one tentatively referred to this taxon. This new species represents the most complete and well-preserved chaoyangopterid recorded to date. Along with a set of characters (low premaxillary crest above the nasoantorbital fenestra extending posteriorly, posterior premaxillary process arched and curving posteriorly, a slightly convex sternal articulation surface of coracoid, and a fibular shaft close to proximal articulation strongly arched posteriorly), this species also provides new information both on the unknown palatal region of this clade, and on the rarely preserved (in place) ear portion with stapes. Moreover, M. youhao sheds light on paleoecological aspects, while also giving new information about the taxonomic diversity of this peculiar group of Jiufotang pterosaurs. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
21. LACK OF ASSORTATIVE MATING FOR TAIL, BODY SIZE, OR CONDITION IN THE ELABORATE MONOMORPHIC TURQUOISE-BROWED MOTMOT (EUMOMOTA SUPERCILIOSA).
- Author
-
MURPHY, TROY G.
- Subjects
- *
MOMOTIDAE , *BIRD reproduction , *NATURAL selection , *BIOLOGICAL evolution , *ORNITHOLOGY , *BEHAVIOR - Abstract
The article discusses the results of a study which examined whether mutual sexual selection maintains the Turquoise-browed Motmot's elaborate tail plumage. The study showed that the assortative mating measured within all pairs of the study population does not support the mutual sexual selection hypothesis that the tail is sexually selected in males only and that the natural selection accounts for the evolutionary maintenance of the elaborate female tail.
- Published
- 2008
- Full Text
- View/download PDF
22. Melanin, carotenoid and structural plumage ornaments: information content and role in great tits Parus major.
- Author
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Hegyi, Gergely, Szigeti, Beáta, Török, János, and Eens, Marcel
- Subjects
FEATHERS ,COLORS ,MELANINS ,CAROTENOIDS ,SIGNALS & signaling ,PARUS ,REFLECTANCE ,PTILOCHRONOLOGY ,TITMICE - Abstract
The importance of plumage colour as an indicator of individual quality and the basis of sexual selection has long been recognized. Of the three generally distinguished classes of plumage colours, melanin-based ornaments are traditionally considered to provide less reliable information than carotenoid-based traits. However, the role of structural ornaments in multiple signalling systems has rarely been examined, and no study has compared the information content and role of the three ornament types simultaneously. Here we investigated three plumage ornaments in great tits Parus major: the size of the melanin-based breast stripe, the carotenoid-based colour of the yellow breast and the structurally based reflectance properties of the black crown. We worked on both the mechanistic and the functional levels. First, we assessed the dependence of ornaments on body condition during moult using ptilochronology. Second, we estimated assortative mating for these traits, as a measure of mutual sexual selection. Only the spectral attributes of crown feathers correlated with body condition during moult. However, breast stripe size was related to age, while the brightness of the yellow breast indicated body size. Relative crown ultraviolet reflectance was much higher in males than in females. Assortative mating was strongest for crown ultraviolet reflectance, but composite measures suggest that a system of multiple sexually selected traits with different information content may work in this population. These data support the accumulating evidence that the condition-dependence of melanin and carotenoid coloration is not qualitatively different. They also suggest that more research should target the reflectance properties of dark plumage areas in general, and ultraviolet crown ornamentation in tits in particular. [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
- View/download PDF
23. Mutual ornamentation, sexual selection, and social dominance in the black swan.
- Author
-
Ken Kraaijeveld, John Gregurke, Carol Hall, Jan Komdeur, and Raoul A. Mulder
- Subjects
BLACK swan ,SEXUAL selection ,ANIMAL social behavior ,FEATHERS - Abstract
We investigated the adaptive significance of a sexually monomorphic ornament in the black swan Cygnus atratus. Both sexes grow curled feathers on their wings (range 7–22 curled feathers per wing), which are displayed prominently in a range of social interactions. The number of curled feathers increased until the birds reached sexual maturity (at 2 years of age) but did not vary with age thereafter. We found evidence for both sexual and social functions of the ornament. Paired, mature individuals of both sexes had higher numbers of curled feathers than unpaired, mature birds, and individuals paired assortatively with respect to curled feather number, suggesting the feathers may be involved in mutual sexual selection. More ornamented individuals were dominant in agonistic interactions with birds of the same sex and pairing status. Highly ornamented pairs were also more likely to maintain extended tenancy of preferred cygnet feeding areas, which resulted in improved offspring survival. The curled feathers thus appear to function as a signal of social dominance, which is highly correlated with reproductive success and is therefore a reliable signal of parental quality in mate choice. [ABSTRACT FROM AUTHOR]
- Published
- 2004
- Full Text
- View/download PDF
24. Eyes of love: Java sparrows increase eye ring conspicuousness when pair-bonded.
- Author
-
Onaga, Jenna and Soma, Masayo
- Subjects
SPARROWS ,SYNCHRONIC order ,EYE movements ,PRIMATES - Abstract
Conspicuous facial features, such as blushing in primates, can communicate social/emotional/physiological states in animals. However, the role of bare facial features is less well studied in birds than in humans or primates. We investigate the Java sparrow, which is characterised by conspicuous rings of swollen and blushed bare skin around the eye. Eye rings show no clear sex difference, although the swelling is associated with breeding. Java sparrows are socially monogamous, with mutual courtships and long-term pair-bonding. Therefore, it is plausible that eye rings function in within-pair communication. Specifically, do eye rings reflect psychophysiological conditions after pair formation? We assessed variations in ring thickness in pair-bonded birds and compared them with single birds and pairs of non-bonded individuals. Over the 12-week experimental period, pair-bonded males and females had an increased ring thickness, unlike the controls. We suggest eye rings convey breeding motivations or serve as fertility signals. This would be of great importance for ensuring reproductive synchrony in tropical birds like the Java sparrow. Our results contribute to understanding the evolution of facial ornamentation in birds, which was often overlooked in the past studies. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
25. Selection on the Fly: Short-Term Adaptation to an Altered Sexual Selection Regime in Drosophila pseudoobscura.
- Author
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Barata, Carolina, Snook, Rhonda R, Ritchie, Michael G, and Kosiol, Carolin
- Subjects
SEXUAL selection ,BIOLOGICAL evolution ,DROSOPHILA ,X chromosome ,POPULATION genetics ,GENE frequency - Abstract
Experimental evolution studies are powerful approaches to examine the evolutionary history of lab populations. Such studies have shed light on how selection changes phenotypes and genotypes. Most of these studies have not examined the time course of adaptation under sexual selection manipulation, by resequencing the populations' genomes at multiple time points. Here, we analyze allele frequency trajectories in Drosophila pseudoobscura where we altered their sexual selection regime for 200 generations and sequenced pooled populations at 5 time points. The intensity of sexual selection was either relaxed in monogamous populations (M) or elevated in polyandrous lines (E). We present a comprehensive study of how selection alters population genetics parameters at the chromosome and gene level. We investigate differences in the effective population size— N e —between the treatments, and perform a genome-wide scan to identify signatures of selection from the time-series data. We found genomic signatures of adaptation to both regimes in D. pseudoobscura. There are more significant variants in E lines as expected from stronger sexual selection. However, we found that the response on the X chromosome was substantial in both treatments, more pronounced in E and restricted to the more recently sex-linked chromosome arm XR in M. In the first generations of experimental evolution, we estimate N e to be lower on the X in E lines, which might indicate a swift adaptive response at the onset of selection. Additionally, the third chromosome was affected by elevated polyandry whereby its distal end harbors a region showing a strong signal of adaptive evolution especially in E lines. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
26. Assortative mating by multiple skin color traits in a seabird with cryptic sexual dichromatism
- Author
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Consejo Nacional de Ciencia y Tecnología (México), Universidad Nacional Autónoma de México, Universidad Autónoma de Tlaxcala (México), López-Rull, Isabel, Nicolás, Leticia, Neri-Vera, Nadia, Argáez, Víctor, Martínez, Margarita, Torres, Roxana, Consejo Nacional de Ciencia y Tecnología (México), Universidad Nacional Autónoma de México, Universidad Autónoma de Tlaxcala (México), López-Rull, Isabel, Nicolás, Leticia, Neri-Vera, Nadia, Argáez, Víctor, Martínez, Margarita, and Torres, Roxana
- Abstract
Most seabirds are monochromatic in plumage, yet many of them show multiple colored integuments, typically modulated by sex steroids such as testosterone, which can reflect individual quality and may be under mutual sexual selection. In the Masked Booby Sula dactylatra, both sexes exhibit multiple color traits that vary in their expression either in color (feet ranging from olive to orange, yellowish bill and black mask) or size (mask). Here, we report sexual differences in skin color traits and evaluate whether their expression is related to individual body condition and plasma testosterone, whether different color traits co-vary, and whether Masked Boobies mate assortatively by color. Our results show that Masked Boobies are sexually dichromatic in foot color and monochromatic in bill and mask color. After controlling for body size and testosterone levels, mask size was larger in females than in males. We found a positive relationship between body condition and plasma testosterone in males and females, suggesting a condition-dependence of plasma androgen levels. Interestingly, foot color covaries positively with testosterone levels in individuals with good body condition and negatively in individuals with poor body condition, whereas mask size was positively related with body condition. Taken together, these results suggest that only individuals in good condition could produce more conspicuous traits. Also, we found a negative relationship between mask color and condition, probably due to the fact that melanin-based traits can pleiotropically vary with other functions, including food intake patterns. Finally, within-individual foot color and mask size were positively correlated and pairs mated assortatively with respect to foot color and mask color and size. We suggest that such a mating pattern may result from a scenario where both sexes choose mates based on traits that convey reliable information of individual quality.
- Published
- 2016
27. Desiccation resistance differences in Drosophila species can be largely explained by variations in cuticular hydrocarbons.
- Author
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Zinan Wang, Receveur, Joseph P., Pu, Jian, Haosu Cong, Richards, Cole, Muxuan Liang, and Chung, Henry
- Published
- 2022
- Full Text
- View/download PDF
28. Female dewlap ornaments are evolutionarily labile and associated with increased diversification rates in Anolis lizards.
- Author
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Yuan, Michael L., Westeen, Erin P., Wogan, Guinevere O. U., and Wang, Ian J.
- Subjects
ANOLES ,SEXUAL dimorphism ,COMPETITION (Biology) ,DECORATION & ornament ,FEMALES ,LIZARDS - Abstract
The evolution of costly signalling traits has largely focused on male ornaments. However, our understanding of ornament evolution is necessarily incomplete without investigating the causes and consequences of variation in female ornamentation. Here, we study the Anolis lizard dewlap, a trait extensively studied as a male secondary sexual characteristic but present in females of several species. We characterized female dewlaps for 339 species to test hypotheses about their evolution. Our results did not support the hypothesis that female dewlaps are selected against throughout the anole phylogeny. Rather, we found that female dewlaps were evolutionary labile. We also did not find support for the adaptive hypothesis that interspecific competition drove the evolution of female dewlaps. However, we did find support for the pleiotropy hypothesis as species with larger females and reduced sexual size dimorphism were more likely to possess female dewlaps. Lastly, we found that female dewlap presence influenced diversification rates in anoles, but only secondarily to a hidden state. Our results demonstrate that female ornamentation is widespread in anoles and the traditional hypothesis of divergent selection between the sexes does not fully explain their evolution. Instead, female ornamentation is likely to be subject to complex adaptive and non-adaptive evolutionary forces. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
29. Intraspecific variation and directional casque asymmetry in adult southern cassowaries (Casuarius casuarius).
- Author
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Green, Todd L., Kay, David Ian, and Gignac, Paul M.
- Subjects
INSPECTION & review ,MORPHOMETRICS ,ADULTS ,PHENOTYPIC plasticity ,MALES ,BIOLOGY - Abstract
The cranial casques of modern cassowaries (Casuarius) have long intrigued researchers; however, in‐depth studies regarding their morphological variation are scarce. Through visual inspection, it has been recognized that casque variability exists between conspecifics. Understanding casque variation has both evolutionary and ecological importance. Although hypothesized to be targeted by selection, intraspecific casque variation has not been quantified previously. Through a large sample of C. casuarius (n = 103), we compared casque shape (lateral and rostral views) between sexes and between individuals from non‐overlapping geographical regions using two‐dimensional (2D) geometric morphometrics. We found no statistically significant differences between the casque shape of females and males and few substantial shape differences between individuals from different geographic areas. Much of the intraspecific variation within C. casuarius is due to casque asymmetries (77.5% rightward deviating, 20.7% leftward deviating, and 1.8% non‐deviating from the midline; n = 111), which explain the high variability of southern cassowary casque shape, particularly from the rostral aspect. Finally, we discuss how our non‐significant findings implicate social selection theory, and we identify the benefits of quantifying such variation for further elucidating casque function(s) and the social biology of cassowaries. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
30. Darwin's sexual selection: Understanding his ideas in context.
- Author
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Padian, Kevin and Horner, John R.
- Subjects
- *
SEXUAL selection , *DATA analysis , *ANIMAL species , *MATE selection ,SEX differences (Biology) - Abstract
Darwin's writings need to be seen in their fullness, as opposed to quote-mining individual sentences without the context of his passages. Sometimes Darwin wrote at length, apparently favorably, about ideas that he subsequently undermined, replacing them with a more integrative view that reflected his own broad compass. Darwin understood that nature is not simple, that not all members of a group may have evolved under the same selective regime, and that variation of all kinds is fundamental to selection in its several forms. Sexual selection requires sexual dimorphism; it is not centred on variation within sexes but on selection for the ability to acquire mates. “Mutual sexual selection” was rejected by Darwin for every species except humans. Mating success is not a matter of mere numbers but of the transmission of the most attractive features to the opposite sex. The term “sexual selection” should only be used when one sex uses a feature not present in the other sex to attract mates or repel rivals for mates. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
31. Sexual selection according to Darwin: A response to Padian and Horner's interpretation.
- Author
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Borkovic, Benjamin and Russell, Anthony
- Subjects
- *
SEXUAL selection , *FOSSIL vertebrates , *DATA analysis , *DIMORPHISM (Biology) , *COMPETITION (Biology) , *ANIMAL courtship , *MAMMALS - Abstract
The interpretation of exaggerated structures in the vertebrate fossil record has been hampered by disagreement over the definition of sexual selection and how it relates to sexual dimorphism. Previous assertions that Darwin placed a requirement of sexual dimorphism on sexual selection are mistaken. Instead, Darwin describes variation within one sex and the exertion of a struggle (expressed as intrasexual competition, intersexual mate choice, or both) as the necessary components of sexual selection. The use of structures by one sex to attract mates or repel rivals for mates occurs independently of any existing sexual differences. Differential mating success is also a requirement of Darwinian sexual selection. Mutual sexual selection is a legitimate concept that was described by Darwin. Sexual selection remains a viable explanatory hypothesis for the presence of exaggerated structures of extinct organisms and need not be dismissed summarily, but should not be employed without support as a default hypothesis. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
32. Is territory defence related to plumage ornaments in the king penguin Aptenodytes patagonicus?
- Author
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Viera, Vanessa, Nolan, Paul M., Côté, Steeve D., Jouventin, Pierre, Groscolas, René, Viera, Vanessa, Nolan, Paul M., Côté, Steeve D., Jouventin, Pierre, and Groscolas, René
- Abstract
Colourful ornaments in monogamous birds may be directed at potential mates or other conspecifics to signal individual condition, reproductive status or fighting ability, especially in monogamous and territorial species. We investigated whether the size of the orange auricular patch may be an indicator of aggressiveness in the king penguin Aptenodytes patagonicus, a monogamous and territorial seabird. The relationship between auricular patch size and defence behaviour was explored relative to territory location (centre vs. periphery of the colony), period of reproduction (early vs. late), state of reproduction (incubation vs. brooding) and sex. The proportion of time spent in territorial defence and the rate of aggressive behaviours were positively correlated with auricular patch size, mainly because central birds were more aggressive than peripheral birds and also had larger patch sizes. The period of reproduction, state of reproduction and sex did not interact with patch size to affect aggressiveness. Our results suggest that the size of the auricular patch in king penguins may be a reliable signal allowing individuals to evaluate the quality of mates or competitors in terms of aggressiveness. Whether aggressiveness is directly linked to patch size or indirectly through body condition, however, remains to be determined. In any event, birds with larger patches seem to gain central territories in the colony, thereby increasing their reproductive success. Finally, our study adds to the growing evidence that the evolution of sexually monomorphic ornaments may stem from mutual sexual selection.
- Published
- 2008
33. Intraspecific variation in the pterosaur Rhamphorhynchus muensteri—implications for flight and socio-sexual signaling.
- Author
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Habib, Michael B. and Hone, David WE.
- Subjects
SEXUAL selection ,FOSSILS ,PTEROSAURIA ,HINDLIMB ,FORELIMB - Abstract
Pterosaurs were the first powered flying vertebrates, with a fossil record that stretches back to about 230 million years before present. Most species are only known from one to three specimens, which are most often fragmentary. However, Rhamphorhynchus muensteri is known from numerous excellent specimens, including multiple specimens with soft tissue preservation. As such, Rhamphorhynchus muensteri is one of the only pterosaurs amenable to analysis for intraspecific variation. It has been previously predicted that elements directly involved in the flight apparatus, such as those of the forelimb, will be more highly constrained in their proportions than other parts of the skeleton. We investigated the degree of variation seen in elements and body parts of Rhamphorhynchus, which represents the best model system among pterosaurs for testing these expectations of intraspecific variation. We recover evidence for high levels of constraint throughout the appendicular and axial elements (head, neck, torso, tail, forelimbs, hindlimbs), suggesting that all were important for flight. We further find that tail variation increases among the largest specimens, suggesting reduced constraint and/or stronger sexual selection on the tail in more mature individuals. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
34. Environmental variation and biotic interactions limit adaptation at ecological margins: lessons from rainforest Drosophila and European butterflies.
- Author
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O'Brien, Eleanor K., Walter, Greg M., and Bridle, Jon
- Subjects
DROSOPHILA ,RAIN forests ,GENETIC variation ,BUTTERFLIES ,GENETIC load ,PHYSIOLOGICAL adaptation - Abstract
Models of local adaptation to spatially varying selection predict that maximum rates of evolution are determined by the interaction between increased adaptive potential owing to increased genetic variation, and the cost genetic variation brings by reducing population fitness. We discuss existing and new results from our laboratory assays and field transplants of rainforest Drosophila and UK butterflies along environmental gradients, which try to test these predictions in natural populations. Our data suggest that: (i) local adaptation along ecological gradients is not consistently observed in time and space, especially where biotic and abiotic interactions affect both gradient steepness and genetic variation in fitness; (ii) genetic variation in fitness observed in the laboratory is only sometimes visible to selection in the field, suggesting that demographic costs can remain high without increasing adaptive potential; and (iii) antagonistic interactions between species reduce local productivity, especially at ecological margins. Such antagonistic interactions steepen gradients and may increase the cost of adaptation by increasing its dimensionality. However, where biotic interactions do evolve, rapid range expansion can follow. Future research should test how the environmental sensitivity of genotypes determines their ecological exposure, and its effects on genetic variation in fitness, to predict the probability of evolutionary rescue at ecological margins. This article is part of the theme issue 'Species' ranges in the face of changing environments (Part II)'. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
35. Density‐dependent patterns of multivariate selection on sperm motility and morphology in a broadcast spawning mussel.
- Author
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Hadlow, Jessica H., Lymbery, Rowan A., and Evans, Jonathan P.
- Subjects
SPERM motility ,MYTILUS galloprovincialis ,MYTILIDAE ,MORPHOLOGY ,SPERMATOZOA ,PHENOTYPIC plasticity ,SPAWNING - Abstract
Sperm cells exhibit extraordinary phenotypic variation, both among taxa and within individual species, yet our understanding of the adaptive value of sperm trait variation across multiple contexts is incomplete. For species without the opportunity to choose mating partners, such as sessile broadcast spawning invertebrates, fertilization depends on gamete interactions, which in turn can be strongly influenced by local environmental conditions that alter the concentration of sperm and eggs. However, the way in which such environmental factors impact phenotypic selection on functional gamete traits remains unclear in most systems. Here, we analyze patterns of linear and nonlinear multivariate selection under experimentally altered local sperm densities (densities within the capture zone of eggs) on a range of functionally important sperm traits in the broadcast spawning marine mussel, Mytilus galloprovincialis. Specifically, we assay components of sperm motility and morphology across two fertilization environments that simulate either sperm limitation (when there are too few sperm to fertilize all available eggs), or sperm saturation (when there are many more sperm than required for fertilization, and the risk of polyspermy and embryonic failure is heightened). Our findings reveal that the strength, form, and targets of selection on sperm depend on the prevailing fertilization environment. In particular, our analyses revealed multiple significant axes of nonlinear selection on sperm motility traits under sperm limitation, but only significant negative directional selection on flagellum length under sperm saturation. These findings highlight the importance of local sperm densities in driving the adaptation of sperm phenotypes, particularly those related to sperm motility, in broadcast spawning invertebrates. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
36. Detecting patterns of correlational selection with sampling error: A simulation study.
- Author
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Simon, Monique Nouailhetas, Marroig, Gabriel, and Arnold, Stevan J.
- Subjects
SAMPLING errors ,BIOLOGICAL fitness ,NONLINEAR regression ,SAMPLE size (Statistics) - Abstract
The adoption of a multivariate perspective of selection implies the existence of multivariate adaptive peaks and pervasive correlational selection that promotes co‐adaptation between traits. However, to test for the ubiquity of correlational selection in nature, we must first have a sense of how well can we estimate multivariate nonlinear selection (i.e., the γ‐matrix) in the face of sampling error. To explore the sampling properties of estimated γ‐matrices, we simulated inidividual traits and fitness under a wide range of sample sizes, using different strengths of correlational selection and of stabilizing selection, combined with different number of traits under selection, different amounts of residual variance in fitness, and distinct patterns of selection. We then ran nonlinear regressions with these simulated datasets to simulate γ‐matrices after adding random error to individual fitness. To test how well could we detect the imposed pattern of correlational selection at different sample sizes, we measured the similarity between simulated and imposed γ‐matrices. We show that detection of the pattern of correlational selection is highly dependent on the total strength of selection on traits and on the amount of residual variance in fitness. Minimum sample size needs to be at least 500 to precisely estimate the pattern of correlational selection. Furthermore, a pattern of selection in which different sets of traits contribute to different functions is the easiest to diagnose, even when using a large number of traits (10 traits), but with sample sizes in the order of 1000 individuals. Consequently, we recommend working with sets of traits from distinct functional complexes and fitness proxies less prone to effects of environmental and demographic stochasticity to test for correlational selection with lower sample sizes. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
37. Mutual mate preferences and assortative mating in relation to a carotenoid-based color trait in blue tits.
- Author
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Caro, Samuel P, Pierre, Léo, Bergès, Matthieu, Bakker, Raldi, Doutrelant, Claire, and Bonadonna, Francesco
- Subjects
ASSORTATIVE mating ,BLUE tit ,CAROTENOIDS ,COLOR of birds ,ANIMAL species ,COLOR - Abstract
Choosing an appropriate sexual partner is a critical decision for many animal species. However, many mechanisms involved in mate choice are still poorly understood. Do both males and females choose their sexual partners, do both sexes use the same criteria for choosing, and do their own phenotype influence the choices they make, are questions that need further investigation. Over two successive experiments conducted in captivity with hand-reared blue tits (Cyanistes caeruleus), we manipulated the color of the chest plumage, a secondary sexual trait that reflects an individual's condition, to create two different color morphs (one pale and one colored). We then tested whether both sexes express a preference, whether they are attracted to the same morphs, and if the subjects' own chest color influences the preference they show. Our data reveal that both sexes are choosy, with females tending to be slightly choosier than males. We also show that both sexes preferentially select individuals with a pale chest plumage over colorful individuals, and this was again more pronounced in females. Finally, paler individuals tend to be selected by birds that are themselves pale, even if this phenotype matching was not very robust. Such a preference for paler individuals is intriguing because mates are predicted to associate with individuals displaying higher, not lower, value of quality signals. It could result from adaptive mechanisms related to avoidance of aggressiveness in a confined environment, avoidance of conflicting sexual signals within individuals, or from cultural mechanisms leading to a preference for individuals that match its own phenotype. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
38. Degree of mutual ornamentation in birds is related to divorce rate.
- Author
-
Ken Kraaijeveld
- Subjects
- *
BIRDS , *SPECIES , *NATURAL selection - Abstract
Many bird species have ornaments that are expressed equally in both sexes. I use comparative analysis to investigate why some monomorphic birds are highly ornamented, whereas others are drab. The results show a significant positive association between the degree of mutual ornamentation and divorce rate. This result is robust to the removal of the effects of phylogeny, site fidelity, residency, coloniality, nest type, mortality, body size and body-size dimorphism. The level of extra-pair paternity was not related to the degree of mutual ornamentation. I argue that these results are compatible with a process of mutual sexual selection, in which both sexes compete for access to mates. The coupled evolution of ornamentation and divorce rate, from the probable ancestral state of a high degree of ornamentation and a low divorce rate, appears to result mainly from a loss of ornamentation under mate fidelity. [ABSTRACT FROM AUTHOR]
- Published
- 2003
- Full Text
- View/download PDF
39. Integrating genomics and multivariate evolutionary quantitative genetics: a case study of constraints on sexual selection in Drosophila serrata.
- Author
-
Reddiex, Adam J. and Chenoweth, Stephen F.
- Subjects
QUANTITATIVE genetics ,SEXUAL selection ,GENOME-wide association studies ,NATURAL selection ,GENOMICS - Abstract
In evolutionary quantitative genetics, the genetic variance–covariance matrix, G, and the vector of directional selection gradients, β, are key parameters for predicting multivariate selection responses and genetic constraints. Historically, investigations of G and β have not overlapped with those dissecting the genetic basis of quantitative traits. Thus, it remains unknown whether these parameters reflect pleiotropic effects at individual loci. Here, we integrate multivariate genome-wide association study (GWAS) with G and β estimation in a well-studied system of multivariate constraint: sexual selection on male cuticular hydrocarbons (CHCs) in Drosophila serrata. In a panel of wild-derived re-sequenced lines, we augment genome-based restricted maximum likelihood to estimate G alongside multivariate single nucleotide polymorphism (SNP) effects, detecting 532 significant associations from 1 652 276 SNPs. Constraint was evident, with β lying in a direction of G with low evolvability. Interestingly, minor frequency alleles typically increased male CHC-attractiveness suggesting opposing natural selection on β. SNP effects were significantly misaligned with the major eigenvector of G, g
max , but well aligned to the second and third eigenvectors g2 and g3 . We discuss potential factors leading to these varied results including multivariate stabilizing selection and mutational bias. Our framework may be useful as researchers increasingly access genomic methods to study multivariate selection responses in wild populations. [ABSTRACT FROM AUTHOR]- Published
- 2021
- Full Text
- View/download PDF
40. The definition of sexual selection.
- Author
-
Shuker, David M and Kvarnemo, Charlotta
- Subjects
SEXUAL selection ,NATURAL selection ,ORIGINALITY ,WOMEN'S roles ,BIOLOGISTS - Abstract
Sexual selection is a key component of evolutionary biology. However, from the very formulation of sexual selection by Darwin, the nature and extent of sexual selection have been controversial. Recently, such controversy has led back to the fundamental question of just what sexual selection is. This has included how we incorporate female-female reproductive competition into sexual or natural selection. In this review, we do four things. First, we examine what we want a definition to do. Second, we define sexual selection: sexual selection is any selection that arises from fitness differences associated with nonrandom success in the competition for access to gametes for fertilization. An important outcome of this is that as mates often also offer access to resources, when those resources are the targets of the competition, rather than their gametes, the process should be considered natural rather than sexual selection. We believe this definition encapsulates both much of Darwin's original thinking about sexual selection, and much of how contemporary biologists use the concept of sexual selection. Third, we address alternative definitions, focusing in some detail on the role of female reproductive competition. Fourth, we challenge our definition with a number of scenarios, for instance where natural and sexual selection may align (as in some forms of endurance rivalry), or where differential allocation means teasing apart how fecundity and access to gametes influence fitness. In conclusion, we emphasize that whilst the ecological realities of sexual selection are likely to be complex, the definition of sexual selection is rather simple. Sexual selection is a crucial component of evolutionary biology yet debate over what forms of selection do or don't comprise sexual selection have re-surfaced over the last couple of decades. Here we provide and justify a definition of sexual selection, that is focused on competition for access to gametes, and challenge that definition with ecologically complex scenarios. We hope this will allow the field to move forward, building on a firm conceptual basis. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
41. Osteology of an exceptionally well-preserved tapejarid skeleton from Brazil: Revealing the anatomy of a curious pterodactyloid clade.
- Author
-
Beccari, Victor, Pinheiro, Felipe Lima, Nunes, Ivan, Anelli, Luiz Eduardo, Mateus, Octávio, and Costa, Fabiana Rodrigues
- Subjects
ANATOMY ,PTEROSAURIA ,ADULTS ,SKULL ,TISSUES - Abstract
A remarkably well-preserved, almost complete and articulated new specimen (GP/2E 9266) of Tupandactylus navigans is here described for the Early Cretaceous Crato Formation of Brazil. The new specimen comprises an almost complete skeleton, preserving both the skull and post-cranium, associated with remarkable preservation of soft tissues, which makes it the most complete tapejarid known thus far. CT-Scanning was performed to allow the assessment of bones still covered by sediment. The specimen can be assigned to Tupa. navigans due to its vertical supra-premaxillary bony process and short and rounded parietal crest. It also bears the largest dentary crest among tapejarine pterosaurs and a notarium, which is absent in other representatives of the clade. The new specimen is here regarded as an adult individual. This is the first time that postcranial remains of Tupa. navigans are described, being also an unprecedented record of an articulated tapejarid skeleton from the Araripe Basin. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
42. Kin-mediated plasticity in alternative reproductive tactics.
- Author
-
Lymbery, Samuel J., Tomkins, Joseph L., Buzatto, Bruno A., and Hosken, David J.
- Subjects
POPULATION density ,PHENOTYPES ,BODY weight ,MITES ,PHENOTYPIC plasticity - Abstract
Conditional strategies occur when the relative fitness pay-off from expressing a given phenotype is contingent upon environmental circumstances. This conditional strategy model underlies cases of alternative reproductive tactics, in which individuals of one sex employ different means to obtain reproduction. How kin structure affects the expression of alternative reproductive tactics remains unexplored. We address this using the mite Rhizoglyphus echinopus, in which large males develop into aggressive 'fighters' and small males develop into non-aggressive 'scramblers.' Because only fighters kill their rivals, they should incur a greater indirect fitness cost when competing with their relatives, and thus fighter expression could be reduced in the presence of relatives. We raised mites in full-sibling or mixed-sibship groups and found that fighters were more common at higher body weights in full-sibling groups, not less common as we predicted (small individuals were almost exclusively scramblers in both treatments). This result could be explained if relatedness and cue variability are interpreted signals of population density, since fighters are more common at low densities in this species. Alternatively, our results may indicate that males compete more intensely with relatives in this species. We provide the first evidence of kin-mediated plasticity in the expression of alternative reproductive tactics. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
43. Does reproductive mode affect sexually-selected coloration? Evaluating UV–blue spots in parthenogenetic and bisexual lizards of the genus Darevskia.
- Author
-
Abramjan, Andran, Arakelyan, Marine, and Frynta, Daniel
- Subjects
LIZARDS ,SEXUAL selection ,INTERSEXUALITY in animals ,PHENOTYPES ,SPECIES - Abstract
Sexual selection often leads to evolution of conspicuous signals, raising the chances of attracting not only potential mates, but also predators. In lacertid lizards, ultraviolet (UV)–blue spots on flanks and shoulders represent such a trait. Some level of correlation between male and female ornamentation is also known to exist. Therefore, the phenotype of females may change in the absence of sexual selection. We tested this hypothesis on a complex of parthenogenetic and bisexual lizards of the genus Darevskia. We evaluated area, counts, and chromatic properties (UV opponency, saturation) of UV–blue spots and compared the values between the clones and their bisexual progenitor species. We found a fair heterogeneity between the parthenogenetic species, but no general tendency toward higher crypsis or conspicuousness. Values of the parthenogens were not significantly different from the values of sexual females. A possible explanation is that the changes in selective forces associated with parthenogenetic reproduction are too small to affect the resulting pattern of selective pressures on the studied traits, or that the phenotypes of the parthenogens result from the unique combination of parental genomes and are conserved by clonal reproduction. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
44. Three-dimensional geometric morphometric analysis of the skull of Protoceratops andrewsi supports a socio-sexual signalling role for the ceratopsian frill.
- Author
-
Knapp, A., Knell, R. J., and Hone, D. W. E.
- Subjects
GEOMETRIC analysis ,SKULL ,MATE selection ,SEXUAL dimorphism ,GEOMETRIC approach ,ONTOGENY ,PARIETAL lobe ,MORPHOMETRICS - Abstract
Socio-sexual selection is predicted to be an important driver of evolution, influencing speciation, extinction and adaptation. The fossil record provides a means of testing these predictions, but detecting its signature from morphological data alone is difficult. There are, nonetheless, some specific patterns of growth and variation which are expected of traits under socio-sexual selection. The distinctive parietal-squamosal frill of ceratopsian dinosaurs has previously been suggested as a socio-sexual display trait, but evidence for this has been limited. Here, we perform a whole-skull shape analysis of an unprecedentedly large sample of specimens of Protoceratops andrewsi using a high-density landmark-based geometric morphometric approach to test four predictions regarding a potential socio-sexual signalling role for the frill. Three predictions—low integration with the rest of the skull, significantly higher rate of change in size and shape during ontogeny, and higher morphological variance than other skull regions—are supported. One prediction, sexual dimorphism in shape, is not supported, suggesting that sexual differences in P. andrewsi are likely to be small. Together, these findings are consistent with mutual mate choice or selection for signalling quality in more general social interactions, and support the hypothesis that the frill functioned as a socio-sexual signal in ceratopsian dinosaurs. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
45. Phenotypic plasticity but no adaptive divergence in cuticular hydrocarbons and desiccation resistance among translocated populations of dung beetles.
- Author
-
Leeson, Sarah A., Kennington, W. Jason, Evans, Theodore A., and Simmons, Leigh W.
- Subjects
DUNG beetles ,PHENOTYPIC plasticity ,MASS spectrometry ,GAS chromatography ,HYDROCARBONS ,SEMIOCHEMICALS ,PHYSIOLOGICAL adaptation - Abstract
Translocated populations must adapt to their new environment to survive. A key aspect of survival for insects is the maintenance of water balance. It is thought that insects can adapt to dry environments by adjusting their cuticular hydrocarbon (CHC) profile to reduce water loss, though there is limited empirical support for this, and studies generally focus on other roles of CHCs, such as chemical communication. We tested for phenotypic adaptation in introduced populations of the Mediterranean dung beetle Onthophagus taurus, which have become established along a climatic gradient from dry northern to wet southern locations in southwestern Australia. We compared CHC profiles and desiccation resistance between northern and southern populations of the species. To quantify desiccation resistance, we measured both the rate of weight loss and time until death in beetles incubated at 35 °C. We tested for associations between these measures of desiccation resistance and CHC profiles, which were obtained through gas chromatography mass spectrometry. The abundance of CHCs was positively associated with desiccation resistance, and individuals that underwent the desiccation treatment produced a greater quantity of several CHC compounds indicating their ability to plastically adjust their CHC profile in response to desiccation stress. However, northern populations did not produce more CHCs than southern populations, and southern populations were better able to tolerate desiccation. Our results suggest that CHCs are an important component of desiccation resistance in O. taurus. However, the lack of evidence for local adaptation to the drier northern climate suggests there may be constraints to increasing desiccation resistance, and demonstrates the importance of considering local environmental conditions before translocating populations to new locations. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
46. Does evolution of echolocation calls and morphology in Molossus result from convergence or stasis?
- Author
-
Loureiro, Livia O., Engstrom, Mark D., and Lim, Burton K.
- Subjects
COMPETITION (Biology) ,CONVERGENT evolution ,MORPHOLOGY - Abstract
Although many processes of diversification have been described to explain variation of morphological traits within clades that have obvious differentiation among taxa, not much is known about these patterns in complexes of cryptic species. Molossus is a genus of bats that is mainly Neotropical, occurring from the southeastern United States to southern Argentina, including the Caribbean islands. Molossus comprises some groups of species that are morphologically similar but phylogenetically divergent, and other groups of species that are genetically similar but morphologically distinct. This contrast allows investigation of unequal trait diversification and the evolution of morphological and behavioural characters. In this study, we assessed the role of phylogenetic history in a genus of bat with three cryptic species complexes, and evaluated if morphology and behavior are evolving concertedly. The Genotype by Sequence genomic approach was used to build a species-level phylogenetic tree for Molossus and to estimate the ancestral states of morphological and echolocation call characters. We measured the correlation of phylogenetic distances to morphological and echolocation distances, and tested the relationship between morphology and behavior when the effect of phylogeny is removed. Morphology evolved via a mosaic of convergence and stasis, whereas call design was influenced exclusively through local adaptation and convergent evolution. Furthermore, the frequency of echolocation calls is negatively correlated with the size of the bat, but other characters do not seem to be evolving in concert. We hypothesize that slight variation in both morphology and behaviour among species of the genus might result from niche specialization, and that traits evolve to avoid competition for resources in similar environments. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
47. Metabolic rate, context‐dependent selection, and the competition‐colonization trade‐off.
- Author
-
Pettersen, Amanda K., Hall, Matthew D., White, Craig R., and Marshall, Dustin J.
- Subjects
BODY temperature ,MARINE invertebrates ,METABOLISM ,REPRODUCTION ,RATES ,COMPETITION (Biology) - Abstract
Metabolism is linked with the pace‐of‐life, co‐varying with survival, growth, and reproduction. Metabolic rates should therefore be under strong selection and, if heritable, become less variable over time. Yet intraspecific variation in metabolic rates is ubiquitous, even after accounting for body mass and temperature. Theory predicts variable selection maintains trait variation, but field estimates of how selection on metabolism varies are rare. We use a model marine invertebrate to estimate selection on metabolic rates in the wild under different competitive environments. Fitness landscapes varied among environments separated by a few centimeters: interspecific competition selected for higher metabolism, and a faster pace‐of‐life, relative to competition‐free environments. Populations experience a mosaic of competitive regimes; we find metabolism mediates a competition‐colonization trade‐off across these regimes. Although high metabolic phenotypes possess greater competitive ability, in the absence of competitors, low metabolic phenotypes are better colonizers. Spatial heterogeneity and the variable selection on metabolic rates that it generates is likely to maintain variation in metabolic rate, despite strong selection in any single environment. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
48. Modularity and heterochrony in the evolution of the ceratopsian dinosaur frill.
- Author
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Prieto‐Márquez, Albert, Garcia‐Porta, Joan, Joshi, Shantanu H., Norell, Mark A., and Makovicky, Peter J.
- Subjects
DINOSAURS ,FOSSILS ,MUSCLES ,ANTLERS ,ELK - Abstract
The fossil record provides compelling examples of heterochrony at macroevolutionary scales such as the peramorphic giant antlers of the Irish elk. Heterochrony has also been invoked in the evolution of the distinctive cranial frill of ceratopsian dinosaurs such as Triceratops. Although ceratopsian frills vary in size, shape, and ornamentation, quantitative analyses that would allow for testing hypotheses of heterochrony are lacking. Here, we use geometric morphometrics to examine frill shape variation across ceratopsian diversity and within four species preserving growth series. We then test whether the frill constitutes an evolvable module both across and within species, and compare growth trajectories of taxa with ontogenetic growth series to identify heterochronic processes. Evolution of the ceratopsian frill consisted primarily of progressive expansion of its caudal and caudolateral margins, with morphospace occupation following taxonomic groups. Although taphonomic distortion represents a complicating factor, our data support modularity both across and within species. Peramorphosis played an important role in frill evolution, with acceleration operating early in neoceratopsian evolution followed by progenesis in later diverging cornosaurian ceratopsians. Peramorphic evolution of the ceratopsian frill may have been facilitated by the decoupling of this structure from the jaw musculature, an inference that predicts an expansion of morphospace occupation and higher evolutionary rates among ceratopsids as indeed borne out by our data. However, denser sampling of the meager record of early‐diverging taxa is required to test this further. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
49. Impacts of environmental heterogeneity on natural selection in a wild bird population*.
- Author
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Houle, Carolyne, Pelletier, Fanie, Bélisle, Marc, and Garant, Dany
- Subjects
BIRDS ,BIRD populations ,NATURAL selection ,TREE populations ,HETEROGENEITY ,HIGH temperatures ,ENVIRONMENTAL auditing - Abstract
Natural selection has been studied for several decades, resulting in the computation of thousands of selection estimates. Although the importance of environmental conditions on selection has often been suggested, published estimates rarely take into account the effects of environmental heterogeneity on selection patterns. Here, we estimated linear and nonlinear viability selection gradients on morphological traits of 12‐day old nestlings in a wild population of tree swallows (Tachycineta bicolor) across a large‐scale heterogeneous study system in southern Québec, Canada. We assessed the environmental drivers of nestling survival and evaluated their effects on strength and direction of selection gradients. Separate analyses of environmental variables showed that high temperatures and heavy rainfall caused stronger positive linear selection on morphological traits. Weaker linear selection was also measured in more extensively cultivated areas. Both strength and shape of nonlinear quadratic and correlational components of selection were modified by environmental variables. Considering all environmental variables revealed that precipitation since hatching affected patterns of linear selection on traits, while temperatures since hatching shaped nonlinear selection patterns. Our study underlines the importance of quantifying linear and nonlinear natural selection under various environmental conditions and how the evolutionary response of traits may be affected by ongoing human‐induced environmental changes. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
50. Exposure to UV radiance predicts repeated evolution of concealed black skin in birds.
- Author
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Nicolaï, Michaël P. J., Shawkey, Matthew D., Porchetta, Sara, Claus, Ruben, and D'Alba, Liliana
- Subjects
WARM-blooded animals ,HUMAN skin color ,COLOR of birds ,RADIANCE ,SKIN ,ULTRAVIOLET radiation ,IRRADIATION - Abstract
Plumage is among the most well-studied components of integumentary colouration. However, plumage conceals most skin in birds, and as a result the presence, evolution and function of skin colour remains unexplored. Here we show, using a database of 2259 species encompassing >99% of bird genera, that melanin-rich, black skin is found in a small but sizeable percentage (~5%) of birds, and that it evolved over 100 times. The spatial distribution of black skin follows Gloger's rule, which states that pigmentation of endothermic animals increases towards the equator. Furthermore, most black-skinned birds inhabit high irradiation regions, and tend to be bald and/or have white feathers. Thus, taken together, our results suggest that melanin-rich, black skin helps to protect birds against ultraviolet irradiation. More generally, our results illustrate that feathered skin colour varies taxonomically, ontogenetically and temporally, providing an additional dimension for avian colour research. In contrast to bird plumage, little is known about the evolution of bird skin color. Here, Nicolaï et al. find that black skin has evolved over 100 times in birds and is associated with baldness and/or white feathers as well as with high irradiation habitats, suggesting a role in UV protection. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
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