Tesi sul tema "Sexual selection in animals"
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1
Jennions, Michael D. "Signalling and sexual selection in animals and plants". Thesis, University of Oxford, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.670250.
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2
Smith, Herbie. "New models of sympatric speciation through sexual selection in animals". Thesis, University of Southampton, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310754.
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3
Servedio, Maria Rose. "Preferences, signals, and evolution : theoretical studies of mate choice copying, reinforcement, and aposematic coloration /". Digital version accessible at:, 1998. http://wwwlib.umi.com/cr/utexas/main.
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Thornhill, Gary Marshal. "Sexual selection in Fowler's toad, Bufo woodhousei fowleri /". The Ohio State University, 1985. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487260859497575.
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5
Hasson, Oren. "Theoretical studies of the evolution of male display by sexual selection". Diss., The University of Arizona, 1987. http://hdl.handle.net/10150/184261.
Testo completoAbstract (sommario):
In this study I present a new mechanism for the evolution of male display as a consequence of female choice. I use a population genetic model to show that if female preferences for better males are based on a cue that is an integral part of male adaptation, a display may evolve if it amplifies the variance in this cue, and hence increases female resolution power with respect to male quality. This evolutionary mechanism is used as a core of a theory that explains the evolution of male display and adaptive female choice (i.e. female preferences that evolve because of their association with high quality genes). I argue that because an amplifying display (termed "amplifier") decreases mating success of males of poor quality, modifiers are likely to evolve that decrease the expression of the amplifier when associated with the poor quality males. As a result, the amplifier's expression becomes an indicator of male quality, and provides sufficient conditions for the evolution of a new type of female choice that is based on the amplifier's expression. This process may lead, in turn, to further changes in both female choice and male display, emphasizing either the amplifying effect of displays or their indicating effect. I show that the direction of these changes may depend on the cost that the amplifier confers on male viability, and on the degree of polygyny of the mating system in concern. I also outline explicit predictions for empirical tests.
6
ZEH, DAVID WAYNE. "ECOLOGICAL FACTORS, PLEIOTROPY, AND THE EVOLUTION OF SEXUAL DIMORPHISM IN CHERNETID PSEUDOSCORPIONS (PHORESY, QUANTITATIVE GENETICS, SEXUAL SELECTION)". Diss., The University of Arizona, 1986. http://hdl.handle.net/10150/183995.
Testo completoAbstract (sommario):
The determinants of sexual dimorphism in a family of false scorpions (Pseudoscorpionida, Chernetidae) were investigated experimentally and with a literature analysis of comparative morphometric and habitat data. Species vary in the extent to which males and females differ in size of the conspicuous, prehensile pedipalps. Patterns within the Chernetidae suggest that dimorphism is a highly variable condition, relatively unconstrained by phylogenetic influences. The evolution of species with enlarged male pedipalps appears to be associated with a change from nonpairing to pairing sperm transfer behavior, and aggressive mate acquisition by males. Experiments with Dinocheirus arizonensis demonstrate a high correlation between male combat ability and chela size. Comparison of male and female life histories show prolonged development in males, and morphological comparisons implicate pedipalp dimorphism as a causative factor in this developmental rate difference. Prolonged development may be particularly costly to males, given the pattern of female sexual receptivity in this species. Females were found to become unreceptive soon after mating and remain so throughout a protected period of brood development. Experimental manipulations suggest that the male developmental rate cost is only outweighed under high density conditions when superior combat ability results in increased mating success. Repeated measures experiments failed to show any correlation between male pedipalp size and number of spermatophores accepted by a female. Parent-offspring regressions suggest the existence of additive genetic variance for male chela size and indicate a strong genetic correlation between this trait and cephalothorax length. Full-sib phenotypic correlations suggest that in D. arizonensis sexual divergence through sexual selection may be constrained by a high genetic correlation between males and females. Finally, the role of phoresy in the colonization of ephemeral, patchy habitats is investigated. Results support the hypothesis that attachment of pseudoscorpions to larger, more mobile arthropods represents a behavior functioning specifically for dispersal.
7
Head, Megan School of Biological Earth & Environmental Sciences UNSW. "Evolutionary consequences of the costs of mate choice". Awarded by:University of New South Wales. School of Biological, Earth and Environmental Sciences, 2005. http://handle.unsw.edu.au/1959.4/22414.
Testo completoAbstract (sommario):
While the existence of costs of mate choice is well accepted, the effects that these costs have on mating systems and the evolution of mate choice are controversial. The aim of this thesis is to explore a range of different types of costs, including costs of being choosy (using guppies, Poecilia reticulata) and costs of mating with attractive males (using house crickets, Acheta domesticus), and investigate how these costs influence female mating behaviour, sexual selection on males and the evolution of mate choice. I use a range of experimental techniques to investigate these questions including: comparisons of feral populations of guppies (Chapter Two), laboratory experiments that manipulate the social (sex ratio, density; Chapters Three and Four) and physical (water current; Chapter Five) environment in which guppies live, genetic paternity analysis and multivariate selection analysis (Chapter Four). I also conduct longitudinal studies of house crickets that estimate the net fitness consequences (Chapter Six) and indirect effects (Chapter Six and Seven) of mating with attractive males. My results demonstrate that the physical and social environment of individuals are important in determining the costliness of both sexual display and mate choice, and thus influence the mating behaviour of males and females. These differences in mating behaviour are often thought to lead to differences in sexual selection on males. My study of the effects of operational sex ratio and density on multivariate sexual selection, however, indicates that differences in behaviour may not necessarily translate into differences in selection. In contrast to predictions of recent theory, my results also indicate that although there are many costs to being choosy and to mating with attractive males, these may be outweighed by indirect benefits. Hence, despite direct costs of choice, mate choice may evolve via indirect benefits to females. Indirect benefits that are often neglected in sexual selection studies, that I show to be important in determining the net fitness of mating with attractive males, include the attractiveness of sons and the mate choice decisions of daughters. These results highlight the importance of examining the consequences of mate choice over multiple generations.
8
Mountjoy, Donald James. "Male song and sexual selection in the European starling". Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=41726.
Testo completoAbstract (sommario):
The function of the complex song of the European Starling (Sturnus vulgaris) was examined. Song playback experiments showed that both male and female starlings were attracted by song, and complex song inhibited males from entering nestboxes. Wild starlings (at least two years old when first recorded) showed extensive changes in the composition of their song phrase repertoires and most also increased the size of their repertoires, which will result in a correlation between age and repertoire size in this species. Females prefer males that have more complex song, and this preference remained significant when preferences for certain nest sites were controlled. Males with larger repertoires did not spend more time incubating or make more feeding visits to nestlings than did males with smaller repertoires. The evolution of complex song in the European starling is consistent with an age-indicator model of sexual selection, in which aspects of male quality correlated with age are advertised by the complexity of male song.
9
Persaud, Kamini N. Galef Bennett G. "Male sexual coercion, female mate choice and control of fertilization in Japanese quail (Coturnix japonica) /". *McMaster only, 2005.
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10
Winquist, Steven Todd. "A comparative analysis of two secondary sexual characters in birds". Thesis, McGill University, 1993. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=26184.
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This thesis investigates the evolution of two secondary sexual characters in birds, large male body size and exaggerated male tail length. To determine whether the elaboration of these two characters is associated with two correlates of sexual selection intensity, mating system and parental care, I collected and examined morphological information for 1,990 species and natural history data for 745 species. Comparative studies should account for the problem of related species sharing similarities through common descent, so here I investigate associations with contrast scores that measure the variation radiating from unique ancestral nodes in a phylogeny. I show that greater polygyny correlates strongly with increasing male size but only slightly with longer male tail length, and that lesser paternal care correlates strongly with both traits. These results indicate that the evolution of increased male body size and exaggerated male tail length in birds is substantially influenced by the intensity of sexual selection.
11
Preziosi, Richard F. "Sexual size dimorphism and selection in the waterstrider Aquarius remigis". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape16/PQDD_0009/NQ30363.pdf.
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Beal, Christy Ann. "Sexual selection and paternal care in Rhynocoris tristis (Hemiptera: Reduviidae)". Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 51 p, 2006. http://proquest.umi.com/pqdweb?did=1203553521&sid=1&Fmt=2&clientId=8331&RQT=309&VName=PQD.
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Veit, Allison C. "Tail streamer function and sexual selection in the red-tailed tropicbird /". Internet access available to MUN users only, 2003. http://collections.mun.ca/u?/theses,155455.
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Street, Sally E. "Phylogenetic comparative investigations of sexual selection and cognitive evolution in primates". Thesis, University of St Andrews, 2014. http://hdl.handle.net/10023/11198.
Testo completoAbstract (sommario):
A full understanding of any biological trait requires investigation of its evolutionary origin. Primates inspire great curiosity amongst researchers due to the remarkable diversity across species in both anatomical and behavioural traits, including sociality, sexual behaviour, life histories, neuro-anatomy, cognitive abilities and behavioural repertoires. The study of primates has involved comparative approaches since its inception, however, the necessary tools for statistically investigating the macro-evolutionary processes responsible for current diversity in biological traits have been developed only in the last 30 years or so, namely phylogenetic reconstruction and phylogenetic comparative methods. Amongst a multitude of evolutionary questions that can be addressed by phylogenetic comparative analyses, this thesis attempts to address two in particular, concerning primates. First, chapters 3 and 4 use meta-analysis and phylogenetic comparative analyses to investigate the evolution of large, brightly coloured ‘exaggerated sexual swellings' in female Catarrhine (‘Old World') primates. Together, chapters 3 and 4 show that such swellings are signals of temporal fertility, and present evidence to suggest that swellings co-evolved with conditions favouring male mate choice and cryptic female choice, therefore shedding light on the general conditions under which female signals of temporal fertility should evolve. Second, chapters 5 and 6 use phylogenetic comparative analyses investigate the evolution of enlarged brain size in the primate order. Together, chapters 5 and 6 suggest that multiple selection pressures have contributed to diversity in brain size and cognitive traits across primates, including sociality, intra-sexual competition and extended life history. Further, analyses presented in chapter 6 suggest that reliance on learned behaviour is a self-reinforcing evolutionary process, favouring ‘runaway' increases in cognitive abilities and reliance on culture in some primate lineages, which parallels increases in brain size, cognitive ability and reliance on culture in human evolution.
15
Delhey, J. Kaspar V. "Sexual selection and blue tit (Parus caeruleus) crown coloration". Diss., Connect to this title online, 2005. http://edoc.ub.uni-muenchen.de/archive/00004716/.
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16
Schwartz, Brian A. "Sex-specific investment in incubation and the reproductive biology of two tropical antbird". [Missoula, Mont.] : The University of Montana, 2008. http://etd.lib.umt.edu/theses/available/etd-05072008-151032/unrestricted/MSc_Thesis_Brian_A._Schwartz2008.docx.
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Dhakal, Preeti. "Tracing sperm in multiply-mated female Anastrepha suspensa, (Diptera:Tephridae) /". View online, 2008. http://repository.eiu.edu/theses/docs/32211131458627.pdf.
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18
Fraser, Gail S. "Parental care and sexual selection in socially monogamous crested auklets (Aethia cristatella)". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape7/PQDD_0021/NQ54836.pdf.
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19
Ophir, Alexander G. Galef Bennett G. "Mate assessment and non-independent mate choice by female Japanese quail (Coturnix japonica) /". *McMaster only, 2003.
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20
Walton, Hilary Catherine. "Sexual selection in the Gray Tree Frog, Hyla versicolor: an integrated view of male-male competition and female choice in the field". Columbus, Ohio : Ohio State University, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1133298654.
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Peixoto, Paulo Enrique Cardoso. "Sistemas de acasalamento com defesa territorial : evolução, regras das disputas e seleção de territorios em satirineos neotropicais". [s.n.], 2009. http://repositorio.unicamp.br/jspui/handle/REPOSIP/316384.
Testo completoAbstract (sommario):
Orientador: Woodruff Whitman BensonTese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia
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Resumo: Brigas territoriais entre machos de insetos voadores são resolvidas das mais variadas formas. Em borboletas, existem evidencias de que tamanho, idade e motivação são importantes determinantes das chances de vitória. No entanto, as regras utilizadas nas brigas, o contexto biológico que afeta a intensidade dos comportamentos agonisticos e o papel funcional das características dos machos na geração de custos durante os confrontos ainda são pouco conhecidos. Neste trabalho investiguei uma serie de características que podem influenciar os custos e benefícios dos confrontos territoriais utilizando as espécies de satirineos Hermeuptychia hermes (Fabricius, 1775), Moneuptychia soter (Buttler, 1877) e Paryphthimoides phronius (Buttler, 1867) como modelos de estudo. No capitulo 1 investiguei se as disputas intra-especificas pela posse de territórios em machos de H. hermes e de M. soter ocorrem com contato físico e quais podem ser as características funcionalmente relevantes para a distinção entre machos territoriais e não territoriais. Para tanto, documentei as brigas entre machos utilizando filmagens de alta velocidade e realizei comparações morfológicas e fisiológicas entre machos possuidores de territórios (residentes) e machos que ocuparam territórios nos quais os residentes originais foram removidos (intrusos). Machos residentes de H. hermes apresentaram massa corporal e muscular similares as dos seus pares intrusos, porem, possuíram menor desgaste alar e maior quantidade de lipídeos. Machos residentes de M. soter, por outro lado, foram mais pesados que os machos intrusos que ocuparam seus territórios. Machos de H. hermes podem dividir a interação em vôos circulares, espirais ascendentes e perseguições lineares, enquanto machos de M. soter usam vôos circulares mais lentos, os quais são seguidos por perseguições lineares e emissões de som (estalos). Contatos físicos não foram registrados para nenhuma espécie. No capitulo 2 investiguei o papel da residência previa na resolução de conflitos territoriais entre machos de H. hermes. Ao induzir disputas entre dois machos que se comportaram como residentes (um residente original e um residente induzido) e compara-las com disputas naturais entre machos residentes e intrusos, foi possível demonstrar que a residência previa aumenta as chances de vitória em um combate. Massa corporal afetou positivamente as chances de vitória nas brigas induzidas, mas não nas brigas naturais. Finalmente no capitulo 3, investiguei a influencia da presença de recursos alimentares no estabelecimento de territórios de acasalamento por machos de P. phronius. Machos desta espécie defendem sítios de acasalamento localizados em manchas de sol sem recursos evidentes. No entanto, manchas de sol previamente desocupadas passaram a ser defendidas depois de receberem frutas fermentadas. Apesar de machos que se estabeleceram nestes locais aparentemente se alimentarem das frutas, experimentos de escolha de territórios sugerem que eles preferem defender sítios sem recursos e utilizam a defesa de áreas com alimento como tática alternativa de acasalamento. Este estudo representa a primeira investigação deste tipo de variação nas táticas de acasalamento em borboletas. Alem de auxiliar a compreensão da evolução de determinados sistemas de localização de parceiros, esse sistema permite testar qual a implicação da existência de mais de uma tática reprodutiva na intensidade dos confrontos territoriais entre machos
Abstract: Territorial conflicts in flying insects may be resolved through many different ways. In male butterflies, size, age and motivation are often reported as important determinants of the winning chances. However, the rules used when fighting, the biological context that affects the intensity of agonistic behaviors, and the functional role of male traits in the contests costs generation are poorly known. In this study I investigated a series of characteristics that may influence the costs and benefits of territorial conflicts using the satyrine species Hermeuptychia hermes (Fabricius, 1775), Moneuptychia soter (Buttler, 1877), and Paryphthimoides phronius (Buttler, 1867) as study organisms. In chapter 1, I used high-speed video imagery to investigate whether intraspecific disputes between male H. hermes and male M. soter occur with physical contact. Additionally, I removed resident males from their defended sites and the subsequent intruders that established on those areas after the resident removal to assess if wing wear, body mass, fat content and flight muscle ratio are important determinants of male residency status. Resident males of H. hermes were similar in body weight and thoracic muscle mass to their intruder rivals, but had fewer wing wear and higher fat content. Resident males of M. soter, on the other hand, were heavier than intruder males. Male H. hermes divided their interaction in up to three phases consisting of circular flights, ascending spirals and back and forth persecutions, whereas male M. soter used much slower circular flights that were often followed by linear persecutions and clicking sound emissions. Physical contacts were not observed for both species. In chapter 2, I investigated the role of previous residence on contest resolution in the butterfly H. hermes. By inducing territorial interactions between males that behaved as residents (one original resident and another resident-induced one) and comparing them with natural contests between resident and intruder males, it was possible to show that previous residence increases the chances of victory. Body mass positively affected the winning chances in the induced fights, but was unimportant among the natural ones. Finally in chapter 3, I investigated the role of feeding resources in the territory establishment by males of the butterfly P. phronius. Male of this species typically defend sunny clearings on the forest edge which do not contain any evident resource. However, previously undefended sunny clearings were occupied by territorial males after receiving soft fermenting fruit. Although males which established on sites containing feeding resources seem to forage on the fermenting fruit, territory selection experiments shows that males prefer to defend sites without resources. This type of variation in the mate locating tactics has never been previously investigated for butterflies. In addition of helping the understanding of the evolutionary processes leading to different mate-locating strategies, this system allows the testing of the influence of different reproductive behaviors on the intensity of territorial conflicts between males
Doutorado
Doutor em Ecologia
22
Hoelzer, Guy Andrew. "Sexual selection and reproductive behavior in the Cortez damselfish (Stegastes rectifraenum)". Diss., The University of Arizona, 1989. http://hdl.handle.net/10150/184781.
Testo completoAbstract (sommario):
The evolutionary processes of sexual selection are investigated in this study by developing a new model for the evolution of epigamic traits and examining the effects of male-male competition, female choice and filial cannibalism in a field population of the Cortez damselfish (Stegastes rectifraenum). Two general processes have been proposed to explain the evolution of epigamic traits: the good genes process and the Fisherian process. A third process leading to the evolution of epigamic traits is presented here: the good parent process. Epigamic traits arise through this process by clarifying the differences in non-heritable parental quality among potential mates. A population genetic model is developed, which further suggests that increases in the frequency of good fathers in the population and phenotypic plasticity enhance the evolution of a good parent trait. The relative strengths of female choice and male-male competition were studied in S. rectifraenum by direct observation of reproductive behavior, and through field experiments. Male body size was found to be the single most important correlate of male reproductive success. Males were removed from their territories to determine the extent to which the vacant territories were valued by other local males. All of the territories were quickly recolonized by new males and sites that initially showed the highest reproductive success continued to be the most successful when new residents were present. A second experiment involved standardizing nests in 30 territories. Under these conditions male body size was no longer correlated with reproductive success, indicating that females are strongly influenced by variance in natural nest sites. Consequently, male-male competition over territories containing high quality nest sites, in combination with female choice of those sites, generates the observed correlation between male body size and reproductive success. Partial clutch filial cannibalism by male S. rectifraenum was studied in the same population. A group of custodial males were fed eggs, while controls remained unfed. Both groups were dissected on the next day to determine the number of eggs in their stomachs. Fed males had significantly fewer eggs in their guts, indicating that they indeed feed on the eggs they guard, rather than take them incidently during nest maintenance activities. A second egg feeding experiment showed that male behaviour and reproductive success are little affected by filial cannibalism; thus it is hypothesized that the energy gained by this behaviour is channelled primarily into growth and survival.
23
Robson, Timothy Ellis. "Sexual selection in the Satin Bowerbird (Ptilonorhynchus violaceus) : taking the female perspective /". [St. Lucia, Qld.], 2004. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe18154.pdf.
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Fernandez, André A. "Selection for the Xmrk oncogene in Xiphophorus cortezi". Ohio : Ohio University, 2008. http://www.ohiolink.edu/etd/view.cgi?ohiou1217515716.
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Ng, Pun-tung, e 吳潘東. "Reproductive traits and sexual selection in the mangrove littorinid snails, Littoraria ardouiniana and L. melanostoma". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hub.hku.hk/bib/B49799356.
Testo completoAbstract (sommario):
According to Darwin, any inheritable traits that enhance fitness (i.e. survival and reproductive success) would be adaptive in a given environment, and therefore subject to natural selection. Some traits that enhance reproductive success but not necessarily survival may, however, evolve through the process of sexual selection. The importance of sexual selection has been intensively studied in “higher animals” birds, mammals and insects but has largely been neglected in “lower animals” such as gastropods. Using two mangrove snails, Littoraria ardouiniana HEUDE 1885 and L. melanostoma GRAY 1839 (Littorinidae) as model species, this thesis documents their various reproductive traits and the occurrence of sexual selection, in an attempt to understand how these animals optimize their fitness.
Being one of a few gastropod families that live closely associated with mangrove habitats, various adaptive reproductive traits are likely to have evolved in the genus Littoraria. The two Littoraria species exhibited several, contrasting, reproductive traits (e.g. reproductive mode; length of reproductive season; seasonal fecundity and egg- or larvae-releasing rate), which may represent species-specific strategies to optimize reproductive success. Both species adopted mucus trail following as a mate-searching strategy; with males being able to discriminate the trails laid by conspecific females and trail orientation during the mating season. Since these two snails mate in the complex habitat of mangrove tree canopies, incorporating some cue into mucus trails to aid mate recognition would increase potential encounter rates and hence reproductive success. 1D proteomic techniques identified two potential pheromones in the trail mucus of female L. ardouiniana, but further investigations are needed to confirm their possible role as sex pheromones.
Evidence for sexual selection was found in L. ardouiniana through male mate choice and male-male competition. Large male L. ardouiniana showed a preference for mucus trails laid by large (= more fecund) females, but this preference was not seen in small males, suggesting a size-based male mate preference. Males of this species also mated with larger females for a longer duration and they showed physical aggression (i.e. they pushed each other) when they encountered a female. These sexual selection mechanisms may drive size-assortative mating patterns in littorinid species and in other animals.
Conversely, L. melanostoma exhibited no obvious male mate preference or male aggression. Such differences in sexual selection patterns from L. ardouiniana were proposed to be a result of differences in operational sex ratio and variation in female quality. As many gastropods show similar mating behaviour to littorinids (i.e. trail following, shell mounting and copulation), sexual selection may operate in a comparable manner in other gastropods. By revealing the complexity of sex roles of males and females (e.g. the mutual occurrence of male mate choice and male-male competition) and condition-dependent male mate preference in these mangrove snails, this thesis has contributed to a missing link between sexual selection and the “lower animals” and provides new insights into the operation of sexual selection in animals.HKU 3 Minute Thesis Award, Champion (2012)
published_or_final_version
Biological Sciences
Doctoral
Doctor of Philosophy
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Bargelletti, Olivia. "Mate preference in female weakly electric fish, Apteronotus leptorhynchus". Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=100762.
Testo completoAbstract (sommario):
This study explores the morphology and electrical behavior of breeding weakly electric fish. Wave-type electric fish communicate by means of a continuous oscillatory electric signal produced by an electric organ. The electric organ discharges at frequencies which are sexually dimorphic in many species of electric fish. This dimorphism is thought to be attributed to female mate choice, although to date, there is no evidence for mate choice or intrasexual competition to have driven the evolution of this signaling dimorphism in wave-type electric fish. Here, I have tracked changes in body shape and electric organ discharge (EOD) frequency of A. leptorhynchus throughout a breeding conditioning period. I find that only females alter the shape of their bodies, presumably to account for increasing egg mass, during the breeding conditioning period. Throughout this period, both females and males do not alter their EOD frequencies significantly. Gravid females were used in an unforced preference test, where they were presented with two live, male A. leptorhynchus. Female preference was indicated by a passage of the female into one of the two male compartments. I find that females show a preference for higher EOD frequency males, while no preference is shown for longer, heavier or larger-amplitude males. Further investigations are needed to dissociate the role of EOD frequency from potentially correlated male traits, such as rate and type of modulations of EOD frequency. The finding of this study that female A. leptorhynchus prefer males of higher EOD frequency establishes wave-type weakly electric fish as a promising model system for the study of the evolution and the sensory mechanisms of female choice.
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Trillo, Paula Alejandra. "Pre- and post-copulatory sexual selection in the tortoise beetle Acromis Sparsa (Coleoptera Chrysomelidae)". [Missoula, Mont.] : The University of Montana, 2008. http://etd.lib.umt.edu/theses/available/etd-03212009-144120/unrestricted/Trillo_umt_0136D_10003.pdf.
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Herridge, Elizabeth J. "The role of polyandry in sexual selection among dance flies". Thesis, University of Stirling, 2016. http://hdl.handle.net/1893/25013.
Testo completoAbstract (sommario):
Elaborate sexual ornaments evolve because mate choice exerts strong sexual selection favouring individuals with high levels of ornament expression. Consequently, even at evolutionary equilibrium, life history theory predicts that ornamental traits should be under directional sexual selection that opposes contrasting selection to reduce the costs associated with their maintenance. Otherwise, the resources used to maintain ornaments should be used to improve other life history functions. Elaborate female ornaments have only evolved in a few species, despite females commonly experiencing strong sexual selection. One explanation for this rarity is that male preferences for female ornaments may be self-limiting: females with higher mating success become less attractive because of the lower paternity share they provide to mates with every additional sperm competitor. The unusual species in which female ornaments do occur can provide rare insight into how selection can favour the expression of expensive characters in females despite their costs. The main goal of my thesis was to determine how sexual selection acts on exaggerated sexual ornaments, and give new insight into how these ornaments may have evolved, in spite of the self-limiting nature of selection on male preferences. To determine the strength of sexual selection acting on female ornamentation in dance flies, we developed new microsatellite markers to assess polyandry rates by genotyping stored sperm in wild female dance flies. We first used polyandry rates to determine whether ornament expression was associated with higher mating success in female Rhamphomyia longicauda, a species that has evolved two distinct and exaggerated female ornaments. Contrary to our predictions, we found no evidence that females with larger ornaments enjoy higher mating success. We then compared polyandry rates in R. longicauda to those of two other species of dance fly, one (Empis aestiva) that has i independently evolved female ornaments on its legs, and another (E. tessellata) that does not possess any discernable female ornaments. We also estimated the opportunity for sexual selection, which we found to be similar and relatively low in all three species. Moreover, the standardized sexual selection gradients for ornaments were weak and non-significant in all three species. Females with more elaborate ornaments, in both within- and cross-species comparisons, therefore did not enjoy higher mating success. Overall, these results suggested that sexual selection operates rather differently in females compared to males, potentially explaining the general rarity of female ornaments. Our amplifications of stored sperm were able to reveal more than just mate numbers. We developed new methods to study patterns of sperm storage in wild female dance flies. We investigated how the skew in sperm genotypes from mixed sperm stores changed with varying levels of polyandry. Our data suggested that sperm stores were dominated by a single male in R. longicauda, and that the proportion of sperm contributed by this dominant male was largely independent of the number of rival males’ sperm present in the spermatheca. These results were consistent with the expectation of males using sperm ‘offence strategies’ in sperm competition and that the most successful male is likely to be the female’s last partner before oviposition. As a whole, my thesis contributed new molecular resources for an understudied and fascinating group of organisms. It exploited these new resources to provide the first estimates of lifetime mating success in several related species, and suggested that the general prediction that ornament expression should covary with sexual selection intensity does not seem to hold in this group. Instead, both the unusual prevalence of ii ornaments and the inconsistent evidence for sexual selection that sustains them in dance flies may owe their existence to the confluence of two important factors. First, the conditions under which sperm competition occurs: as last male precedence is likely, males are selected to prefer the most gravid females to secure a high fraction of her offspring’s paternity as they are unlikely to mate again before oviposition. Second, potent sexually antagonistic coevolution between hungry females and discerning males: females have evolved ornaments to disguise their stage of egg maturity to receive the benefits of nuptial gifts, while males face the challenge of distinguishing between gravidity and ornamentation in females.
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Moynihan, Anna Margaret. "Sexual selection and sex allocation in the gregarious parasitoid wasp Nasonia vitripennis". Thesis, University of St Andrews, 2012. http://hdl.handle.net/10023/3129.
Testo completoAbstract (sommario):
Sex allocation and sexual selection have been heavily studied, but rarely linked. In this thesis I investigated the interface between them in the gregarious parasitoid wasp Nasonia vitripennis, both directly and through their interactions with the mating system and sexual conflict. Chapter 2 investigated sexual selection and mating at the natal site: earlier eclosing males mated more females independently of body size. Nasonia follows Local Mate Competition, which describes how a female laying eggs alone on a patch of resources (a so-called single-foundress) should lay an extremely female-biased brood to minimise competition between her sons, yet ensure all her daughters are fertilised. Based on this I predicted that males with with fewer brothers would be better inseminators. Despite finding significant among-strain variation in (1) single-foundress sex ratio, (2) mate competitiveness when alone and (3) when in competition, (4) sperm resources, but not (5) sperm-depletion (Chapters 3 & 4), I did not find the predicted relationship. Conversely males from strains with more brothers had a higher mating success under competition (Chapter 3) leading to the question: does mating success select on sex ratio or vice versa? Either way it is a result of an interaction between sexual selection and sex allocation. Chapter 5 investigated the role of male post-copulatory courtship on female re-mating, and found that among- strain variation in female re-mating was not associated with variation in the duration of the post-copulatory courtship. Chapter 6 reviewed sexual conflict in the Hymenoptera: their haplodiploid genetics, newly sequenced genomes and varied life- histories provides a base for future research to build on. Finally I highlight the novel links between sexual selection, sex allocation, sexual conflict and the mating system found during my studies that will hopefully prompt future research on this topic.
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Doucet, Stéphanie M. Hill Geoffrey E. "Plumage coloration and morphology in Chiroxiphia manakins interacting effects of natural and sexual selection /". Auburn, Ala., 2006. http://hdl.handle.net/10415/1308.
Testo completo
31
McKeown, Jennifer J. "Modelling the evolution of sexual behaviour". Thesis, University of Stirling, 2014. http://hdl.handle.net/1893/21823.
Testo completoAbstract (sommario):
This thesis presents two studies where natural and sexual selection have interacted to evolve sexual behaviours. The thesis uses mathematical modelling to understand how these forces have caused each behaviour to evolve. This is useful because the results allow for reflection on the potential role of sexual selection in adaptation of these species to a changing environment. The first study is of early male arrival to spring breeding grounds in migratory avian species, this is termed protandry. The study explores the main hypotheses for avian protandry and then tests the susceptibility of each hypothesis to changing environment. The second study is of convenience polyandry in species where there is conflict over mating rate. Females have multiple strategies to avoid harassive males but strategies vary in cost and success rate; she must balance her strategy use to minimise her fitness depreciation. The study identifies the main factors that cause convenience polyandry to evolve and paves the way for future studies to investigate if sexual selection over resistance strategy provides these species a future advantage in adaptation to a changing environment.
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DeFreese, Rachel Lynne. "Fluctuating asymmetry of white-tailed deer antlers". Auburn, Ala., 2007. http://repo.lib.auburn.edu/2007%20Spring%20Theses/DEFREESE_RACHEL_32.pdf.
Testo completo
33
Perreault, Stéphane 1967. "Reproductive tactics in the American redstart". Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=22789.
Testo completoAbstract (sommario):
The occurrence of three reproductive tactics in a population of American redstarts was estimated: extra-pair fertilization, egg-dumping, and male polyterritoriality. Using DNA fingerprinting we show that none of 108 nestlings samples were the result of egg dumping. In contrast, 40% of nestlings were the result of extra-pair fertilizations. Males sired a greater proportion of their broods as they aged. In addition, promiscuous females were never fertilized by males that were younger than their social mates. Whether the poor reproductive performance of younger males was caused by female preference for older males or by intra-sexual competition was not determined. In any case, females would have benefited by mating with older males, if the traits that allowed the survival of the father were inherited by the females' offspring. Only three of 80 males attracted two females through polyterritoriality. One male fledged two broods: he sired both nestlings from his first brood, but none of the four nestlings from his second brood. We concluded that male redstarts can improve their reproductive success by trying to obtain extra-pair copulations, but less so by establishing a second territory.
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Waitt, Corri. "Facial attractiveness among rhesus macaques (Macaca mulatta) : manipulating and measuring preferences for conspecifics' facial characteristics". Thesis, University of Stirling, 2005. http://hdl.handle.net/1893/21425.
Testo completoAbstract (sommario):
The face holds a central role in both human and nonhuman primate social interactions, through the communication of feelings and intentions via facial expressions and by acting as a means of recognising individuals. Humans, however, also employ their faces in mate attraction and assessment, an area that has received little attention in nonhuman primates. Many researchers have proposed that human aesthetic judgments of facial attractiveness have a biological basis, and these preferences have evolved via sexual selection processes during human evolution. The use of the face in attractiveness assessments need not be limited to humans. Rather, there is good reason to suggest that this may also apply to other nonhuman primates, based on homologies in the way in which primates use their faces, and on evidence that the face is a site of sexual selection for many primate species. It was the aim of this thesis to explore whether facial traits may also play a role in judgements of attractiveness in a nonhuman primate, the rhesus macaque( Macaca mulatta), in an effort to understand whether humans are unique in utilising the face as a mechanism of mate assessment. Three factors that are reported to influence facial attractiveness in humans are facial symmetry, sexual dimorphism, and averageness. To assess whether they also play a role in nonhuman primates, a series of experiments were conducted where digital images of adult male and female rhesus macaque faces were altered for these features. Opposite-sexed images were then displayed to adult males and females in a captive setting. Eye gaze measures were utilised to assess visual preference for, and the relative importance of, these traits. These experiments yielded mixed results. Increasing facial symmetry of opposite-sexed conspecifics positively influenced the dependent gaze measures employed here. Manipulating degree of facial sexual dimorphism had little influence on the visual gaze of either sex. Facial averageness positively influenced visual preferences for opposite-sexed conspecifics among both sexes, although increasing degree of averageness did not. The last topic to be explored was facial colouration. Rhesus macaques like, various other species of anthropoid primates, possess facial displays of red secondary sexual colouration. As above, animals viewed digitally altered pale and red versions of opposite-sexed conspecifics. Although females displayed preferences for red male faces, males displayed no clear preferences based on female facial colour. This raises the possibility that male and female facial colour may serve different roles in intraspecific signaling. While it cannot be concluded that visual preferences are indeed indicative of real-life preferences, the results do indicate that animals are not indifferent to variations in conspecific facial features. The present findings have important implications regarding the evolution of facial attractiveness, as they provide the first experimental evidence suggesting that facial features may serve as a mechanism for mate selection across primate taxa and that both human and nonhuman primates may employ similar criteria to appraise facial attractiveness.
35
Martínez-Rivera, Carlos C. "Call timing interactions, aggressive behavior, and the role of acoustic cues in chorus formation in treefrogs". Diss., Columbia, Mo. : University of Missouri-Columbia, 2008. http://hdl.handle.net/10355/5539.
Testo completoAbstract (sommario):
Thesis (Ph. D.)--University of Missouri-Columbia, 2008.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on July 28, 2009) Includes bibliographical references.
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Tori, Wendy P. "Sexual selection in a species with exploded leks the white-crowned Manakin (Pipra pipra) /". Diss., St. Louis, Mo. : University of Missouri--St. Louis, 2008. http://etd.umsl.edu/r3041.
Testo completo
37
Civetta, Alberto. "The evolution of sex-related traits and speciation in Drosophila". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape10/PQDD_0006/NQ42733.pdf.
Testo completo
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Carroll, Kendra. "Mating bias in the red imported fire ant, Solenopsis invicta /". View online, 2008. http://repository.eiu.edu/theses/docs/32211131428178.pdf.
Testo completo
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Siller, Steven Thornton. "Strategically developed phenotypes and the evolution of signals". Thesis, University of Oxford, 1997. http://ora.ox.ac.uk/objects/uuid:01e30a68-b444-40a3-adb2-2245ea045161.
Testo completoAbstract (sommario):
In the first part of this thesis, a general one dimensional theory of strategically determined phenotypes is developed and applied to biological signalling games. Abstract modular modelling techniques are utilised to solve hitherto analytically intractable problems including error-prone signalling, and how to incorporate genetic features into optimization models. Links are drawn between previous biological models, such as the War of Attrition and Strategic Handicap mod- els. Mistakes in previous biological models are recognised and, where possible, rectified. A number of novel insights into biological phenomena arising from the models are presented, including analyses of: when free signals are possible; honest signalling of future paternal investment; dimorphic signals; the effects of the mechanisms of female discrimination in sexual selection on male signalling strategies; and the effects of relatedness on the magnitude and stability of equi- librium signalling strategies. It is argued that Zahavi's proposed demarcation between signal selection and natural selection is unjustifiable from a theoretical perspective. The second part of the thesis concerns the epistatic handicap process of sex- ual selection. Unlike the conditional and revealing handicap mechanisms, the epistatic or 'Zahavian' handicap mechanism of sexual selection has hitherto found scant support in the theoretical literature, as it appeared to function only under the most extreme conditions. A continuous game theory model, a quantitative genetics model, and a three locus major gene model are presented which show that the epistatic handicap mechanism can function, independent of the Fisher process of sexual selection, under reasonable assumptions. More- over, the game theory model illuminates the connection between the strategic and epistatic handicap mechanisms. The quantitative genetics and major gene models, together with a fourth model, are also used to show that a general argu- ment concerning indirect genetic correlations, which has appeared in a number of papers on sexual selection, is specious. Finally, a general theorem on games that satisfy the single-crossing condition (also known as the sorting, Spence-Mirrless, or constant sign condition) which underlies many of the results presented in the first part of the thesis is proven in appendix C. Applying a limit result to this general theorem provides a new proof of, and extensions to, Nash's existence result for equilibria to strategic- form games without having to resort to Kakutani's fixed point theorem.
40
James, Robert Andrew. "The genetics of sexually dimorphic traits implicated in sexual isolation in Drosophila : QTLs and candidate genes". Thesis, St Andrews, 2008. http://hdl.handle.net/10023/547.
Testo completo
41
Talwar, Malvika. "Evolution of signal frequency in Neoconocephalus (Orthoptera: Tettigoniidae) a study of perceptual and environmental sources of selection /". Diss., Columbia, Mo. : University of Missouri-Columbia, 2007. http://hdl.handle.net/10355/5972.
Testo completoAbstract (sommario):
Thesis (Ph. D.)--University of Missouri-Columbia, 2007.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on October 18, 2007) Vita. Includes bibliographical references.
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McDonald, Paul G. "Reproductive success, dimorphism and sex allocation in the brown falcon Falco berigora /". View thesis entry in Australian Digital Theses Program, 2003. http://thesis.anu.edu.au/public/adt-ANU20041111.100436/index.html.
Testo completo
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Fricke, Claudia. "Postmating Sexual Selection and its Role in Population Divergence in Beetles". Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Universitetsbiblioteket [distributör], 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-6583.
Testo completo
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Walters, Lindsey A. "Mate quality and parental investment in the house wren". Diss., Connect to online resource - MSU authorized users, 2008.
Cerca il testo completoAbstract (sommario):
Thesis (PH.D.)--Michigan State University. Zoology Ecology, Evolutionay Biology, and Behavior, 2008.Title from PDF t.p. (viewed on Aug. 11, 2009) Includes bibliographical references (p. 64-72). Also issued in print.
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Svedin, Nina. "Natural and Sexual Selection in a Natural Hybrid Zone of Ficedula Flycatchers". Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-7372.
Testo completo
46
Freeman, Alexandra L. J. "Butterflies as signal receivers". Thesis, University of Oxford, 1998. http://ora.ox.ac.uk/objects/uuid:a441ad53-dba2-406a-ab71-466ac0831782.
Testo completoAbstract (sommario):
This thesis examines the existence of colour preferences in butterflies. Two polymorphic species - the Mocker Swallowtail (Papilio dardanus) and the Silver-Washed Fritillary (Argynnis paphia) are used as study species. Both the basis of colour preferences in mate choice and flower choice during feeding, and the implications of the preferences for the evolution of the species and morphs are investigated. In the Silver Washed Fritillary a non-genetically determined preference exists for highly saturated orange coloration in both mate and flower choice. This is shown not to be due to a bias for orange in colour reception through the use of electroretinograms, measuring the electrical output of the retina when exposed to light of varying wavelengths. It has not been possible, however, to rule out the possibility that the preference for the most common, orange, female morph is learnt. The flower colour preferences of the Mocker Swallowtail are investigated, and it is demonstrated that individuals show an initial preference for blue flowers, and also learn rapidly to feed off flowers of other colours that prove profitable. Their decision to try flowers of other colours is shown to be influenced by the behaviour of other individuals. In previous mate choice experiments, experienced males of the species have been shown to have a preference for the most common, black and white, morph. The colours of the morphs and the spectral sensitivities of the butterflies are analysed quantitatively. The initial and subsequent preferences of naive males are investigated in behavioural experiments, and a possible influence of learning on their subsequent choices is discovered. No influence of female choice is found. This information is then used to create a mathematical model of the population structure, for which it is also necessary to determine the relative payabilities of the model and mimic, and the mating frequency of wild males. The model demonstrates how the observed population structures might arise through evolutionary time. Measurements of the morphology of males and females of Papilio dardanus, and one of its putative models, Danaus chrysippus, shows that in Papilio dardanus females the centre of gravity is positioned significantly further back than in males and in Danaus chrysippus. This positioning far from the wing base has already been shown to handicap an individual escaping from a predator due to decreased acrobatic ability. It has also already been shown that mimetic species tend to have centres of mass positioned further back than non-mimetic species, and hence it is possible that the position of a centre of mass of a butterfly (and its effect on agility) may be a factor in the evolution of mimicry in a species or (where females carry a large egg load) in females of a species only.
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Kime, Nicole Marie. "Female mate choice for socially variable advertisement calls in the cricket frog, Acris crepitans /". Full text (PDF) from UMI/Dissertation Abstracts International, 2001. http://wwwlib.umi.com/cr/utexas/fullcit?p3034556.
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Trozzo, Lara Rae. "Nutrient Effects on Sexual Selection and Comparison of Mating Calls in Katydids (Tettigoniidae)". Kent State University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=kent1366305559.
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Firman, Renee C. "The evolutionary implications of polyandry in house mice (Mus domesticus)". University of Western Australia. School of Animal Biology, 2008. http://theses.library.uwa.edu.au/adt-WU2008.0162.
Testo completoAbstract (sommario):
[Truncated abstract] Despite the costs associated with mating, females of many taxa solicit multiple mates during a single reproductive event (polyandry). Polyandry is clearly adaptive when females gain direct benefits from males at mating. However, polyandry has also been shown to increase female fitness in the absence of direct benefits. Thus, a number of genetic benefit hypotheses have been developed to account for the origin of this behaviour. Although not mutually exclusive, a distinction lays between genetic benefits that propose defense against reproductive failure (nonadditive genetic effects), and those that propose benefits from intrinsic sire effects (additive genetic effects). Nonadditive genetic benefits of polyandry have been documented in a number of species; by soliciting multiple mates females can avoid inbreeding and other forms of incompatibility between parental genotypes. Polyandry may also increase female reproductive success when genetically superior males have greater success in sperm competition, and produce better quality offspring. An inevitable consequence of polyandry is that sperm from rival males will overlap in the female reproductive tract and compete to fertilise the ova. The outcome of sperm competition is typically determined by bias in sperm use by the females, interactions between parental genotypes, and ejaculate characteristics that provide a fertilisation advantage. Thus, sperm competition is recognised as a persuasive force in the evolution of male reproductive traits. Comparative analyses across species, and competitive mating trials within species have suggested that sperm competition can influence the evolution of testis size and sperm production, and both sperm form and sperm function. ... After six generations of selection I observed phenotypic divergence in litter size - litter size increased in the polyandrous lines but not in the monandrous lines. This result was not attributable to inbreeding depression, or environmental/maternal effects associated with mating regime. Genetic benefits associated with polyandry could account for this result if increased litter size were attributable to increased embryo survival. However, males from the polyandrous lineages were subject to sperm competition, and evolved ejaculates with more sperm, suggesting that evolutionary increases in litter size may in part be due to improved male fertility. Finally, Chapter Five is an investigation of the natural variation in levels of polyandry in the wild, and the potential for sperm competition to drive macroevolutionary changes in male reproductive traits among geographically isolated island populations of house mice. I sampled seven island populations of house mice along the coast of Western Australia and, by genotyping pregnant females and their offspring, determined the frequency of multiply sired litters within each population. I applied the frequency of multiple paternity as an index of the risk of sperm competition, and looked for selective responses in testis size and ejaculate traits. I found that the risk of sperm competition predicted testis size across the seven island populations. However, variation in sperm traits was not explained by the risk of sperm competition. I discuss these results in relation to sperm competition theory, and extrinsic factors that influence ejaculate quality.
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Celis, Patricia. "Reproductive success and male traits in the spotless starling, Sturnus unicolor". Thesis, St Andrews, 2009. http://hdl.handle.net/10023/722.
Testo completo