EVOLUTIONARY DYNAMICS OF SEXUAL TRAITS: DEMOGRAPHIC, GENETIC, AND BEHAVIORAL CONTINGENCIES

Persistent Link:
http://hdl.handle.net/10150/194221
Title:
EVOLUTIONARY DYNAMICS OF SEXUAL TRAITS: DEMOGRAPHIC, GENETIC, AND BEHAVIORAL CONTINGENCIES
Author:
Oh, Kevin
Issue Date:
2009
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
The evolution of adaptation depends on genetic and phenotypic variation, both of which are expected to be depleted in populations as a result of selection. Thus, understanding the maintenance of variation in fitness-related traits is of central importance in evolutionary biology as such processes can mitigate the constraining effects of adaptation on evolutionary change. Secondary sexual traits involved in attracting mates offer conspicuous examples of adaptation and are suggestive of strong directional selection, yet abundant variation is commonly observed both within and among populations. One explanation posits that variation in elaborate sexual traits might be maintained by fluctuating selection, such that episodes of intense selection are interspersed by periods in which variation is shielded from elimination, yet little is known about the processes that lead to such heterogeneity. In many cases, mate choice results from highly localized social interactions such that fine scale demographic variation may contribute to variation in patterns of sexual selection, especially when individuals' attractiveness is assessed in comparison to local conspecifics. Additionally, selection on sexual traits might fluctuate when the fitness consequences of mate choice depends on the complementarity of male and female characters, such as when offspring viability is influenced by the genetic relatedness of parents. In this dissertation, I examined demographic, behavioral, and genetic causes of variation in sexually-selected male plumage ornaments in a wild population of house finches (Carpodacus mexicanus). Over a five-year field study, I found that mate choice occurred largely within small social groups, the composition of which was influenced by active social sampling by males, suggesting that variation in male sexual traits may be maintained as a result of behaviors that enable individuals to shape their environment of selection. Additionally, using a panel of neutral molecular markers, I found that parental relatedness predicted multiple metrics of offspring fitness, and also affected the ability of neonates to buffer development from environmental variation, suggesting that inbreeding is likely to have pervasive effects on the evolution of adaptation. Taken together, these studies provide evidence of distinct processes that contribute to the maintenance of quantitative variation in sexual traits in this natural population.
Type:
text; Electronic Dissertation
Keywords:
adaptation; evolution; genetic complementarity; house finch; mate choice; sexual selection
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Ecology & Evolutionary Biology; Graduate College
Degree Grantor:
University of Arizona
Advisor:
Badyaev, Alexander V.
Committee Chair:
Badyaev, Alexander V.

Full metadata record

DC FieldValue Language
dc.language.isoENen_US
dc.titleEVOLUTIONARY DYNAMICS OF SEXUAL TRAITS: DEMOGRAPHIC, GENETIC, AND BEHAVIORAL CONTINGENCIESen_US
dc.creatorOh, Kevinen_US
dc.contributor.authorOh, Kevinen_US
dc.date.issued2009en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractThe evolution of adaptation depends on genetic and phenotypic variation, both of which are expected to be depleted in populations as a result of selection. Thus, understanding the maintenance of variation in fitness-related traits is of central importance in evolutionary biology as such processes can mitigate the constraining effects of adaptation on evolutionary change. Secondary sexual traits involved in attracting mates offer conspicuous examples of adaptation and are suggestive of strong directional selection, yet abundant variation is commonly observed both within and among populations. One explanation posits that variation in elaborate sexual traits might be maintained by fluctuating selection, such that episodes of intense selection are interspersed by periods in which variation is shielded from elimination, yet little is known about the processes that lead to such heterogeneity. In many cases, mate choice results from highly localized social interactions such that fine scale demographic variation may contribute to variation in patterns of sexual selection, especially when individuals' attractiveness is assessed in comparison to local conspecifics. Additionally, selection on sexual traits might fluctuate when the fitness consequences of mate choice depends on the complementarity of male and female characters, such as when offspring viability is influenced by the genetic relatedness of parents. In this dissertation, I examined demographic, behavioral, and genetic causes of variation in sexually-selected male plumage ornaments in a wild population of house finches (Carpodacus mexicanus). Over a five-year field study, I found that mate choice occurred largely within small social groups, the composition of which was influenced by active social sampling by males, suggesting that variation in male sexual traits may be maintained as a result of behaviors that enable individuals to shape their environment of selection. Additionally, using a panel of neutral molecular markers, I found that parental relatedness predicted multiple metrics of offspring fitness, and also affected the ability of neonates to buffer development from environmental variation, suggesting that inbreeding is likely to have pervasive effects on the evolution of adaptation. Taken together, these studies provide evidence of distinct processes that contribute to the maintenance of quantitative variation in sexual traits in this natural population.en_US
dc.typetexten_US
dc.typeElectronic Dissertationen_US
dc.subjectadaptationen_US
dc.subjectevolutionen_US
dc.subjectgenetic complementarityen_US
dc.subjecthouse finchen_US
dc.subjectmate choiceen_US
dc.subjectsexual selectionen_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineEcology & Evolutionary Biologyen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorBadyaev, Alexander V.en_US
dc.contributor.chairBadyaev, Alexander V.en_US
dc.contributor.committeememberPapaj, Daniel R.en_US
dc.contributor.committeememberFerriere, Regisen_US
dc.identifier.proquest10414en_US
dc.identifier.oclc659752045en_US
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