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Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1988. / Vita. Abstract. Includes bibliographical references. Also available via the Internet.

My dissertation focuses on the evolutionary forces that have shaped the chemical signaling system of plethodontid salamanders. Pheromones mediate two phases of plethodontid reproduction: mate attraction prior to courtship and female persuasion during courtship. Substrate-borne chemical signals are believed to play an important role in mate attraction for these animals. A behavioral assay of sex- and species-specific odor preferences in closely related species of Plethodon indicates that: (1) there is asymmetry on the receiver side of the system, wherein male salamanders invest more energy searching for mating partners than do females; (2) substrate-borne chemical signals are sexually dimorphic and male preference strongly favors the female odor versus the male odor; (3) females of allopatric salamander species have evolved distinctive chemical cues; and (4) female chemical signals of sympatric species are divergent and may play a role in sexual isolation. Sexual persuasion is another phase of plethodontid reproduction that is mediated by chemical signals. Plethodontid Receptivity Factor (PRF) is a proteinaceous pheromone that is produced by the male and delivered to the female during courtship. Female receptivity increases following application of this pheromone. PRF is a recent innovation of the male courtship signal, originating in eastern Plethodon (~27 MYA). Codon-substitution models indicate that several amino acid sites along the PRF protein have experienced positive selection. Structural modeling suggests that many of these selected residues are important for receptor binding. Adaptive change in this pheromone is likely driven via a coevolutionary association with female receptors. The male plethodontid courtship signal, however, is comprised of multiple chemical components. I investigate micro- and macro-evolutionary divergence in plethodontid chemical communication by surveying two additional pheromone component genes, PMF and SPL. Like PRF, regions of the PMF and SPL genes have experienced adaptive change. At least one of these components (SPL) has been retained in the signaling system for ~100 MY. However, significant differences in the composition of the courtship pheromone are evident in some plethodontid lineages. It appears as if at least two lineages (Desmognathus and eastern Plethodon) use different major pheromone components and yet achieve the same behavioral response in the female (increased receptivity). / Graduation date: 2005

Early theoretical models for the evolution of male-female pairing were based largely on studies of birds. These models assumed that biparental care of eggs and young was an essential component of pairing. However, male-female pairing is also a relatively common social system in coral-reef fishes, and biparental care of young is extremely rare in this group. Although pairing has been documented in at least 13 families of reef fish, surprisingly little is known about the environmental and social factors that may maintain heterosexual pairs as the basic social units. I tested two hypotheses for pairing in a common Caribbean fish, the cleaning goby Gobiosoma evelynae, a territorial species which inhabits living coral heads. According to the Environmental Constraints Hypothesis, pairing in G. evelynae is simply a consequence of three related environmental parameters--low male mobility, low female density, and a uniform distribution of resources required by females. On reefs off St. Thomas, U.S. Virgin Islands, I found positive size-assortative pairing, frequent male movement between territories, rapid re-pairing by both males and females after experimental removal of a partner, and random distributions of apparently suitable coral heads required by females for territory space. These patterns are inconsistent with the Environmental Constraints Hypothesis for pairing. Mate Guarding is an alternative hypothesis for pairing and is based on social interactions. This hypothesis, which states that paired gobies maintain exclusive access to their partners by expelling all potential sexual rivals, predicts sex- and size-specific aggression toward conspecifics. released large and small male and female gobies directly onto the territories of pairs, and recorded the behavioral responses of the resident fish. As predicted, residents exhibited the greatest aggression toward large intruders of the same sex, and the least aggression toward large intruders of the opposite sex. Unpaired territorial females also responded aggressively to experimentally added females, and ignored added males. These results indicate that male-female pairs are maintained by mutual intrasexual aggression in this species, and that females (and possibly males) defend both partners and other resources associated with their territories. / Graduation date: 1994

For years critics have noticed how Jane Austen uses a cold, a sore throat, a sprained ankle, or some other minor affliction (Watson 336) to further the plots of her novels. Although the recurring motif of illness appears to be nothing more than the recording of everyday trivialities, the frequent appearance of illness during the courtship narratives is intriguing. The bodily production of modesty requires the conscious display of delicacy; however, delicacy requires disability in order to be visible to society. Similarly, sensibility also requires the display of delicacy and, by extension, disability. Applying Judith Butlers performance theory to disability, it is possible to analyze the performance of delicacy used in both the production of modesty and sensibility, and thereby understand the degree to which delicacy is a learned performance rather than an innate feminine trait. Austens heroines display varying degrees of affectation of both modesty and sensibility through their performances of delicacy. These performances serve to highlight each heroines degree of modesty and sensibility, as well as to pique the interest ideally, although not always successfully of potential lovers. The performance of disability through delicacy is an essential feature of the temporary invalidism experienced by the heroines during the courtship narratives of Austens novels.

Graduation date: 1994

For years critics have noticed how Jane Austen uses a cold, a sore throat, a sprained ankle, or some other minor affliction (Watson 336) to further the plots of her novels. Although the recurring motif of illness appears to be nothing more than the recording of everyday trivialities, the frequent appearance of illness during the courtship narratives is intriguing. The bodily production of modesty requires the conscious display of delicacy; however, delicacy requires disability in order to be visible to society. Similarly, sensibility also requires the display of delicacy and, by extension, disability. Applying Judith Butlers performance theory to disability, it is possible to analyze the performance of delicacy used in both the production of modesty and sensibility, and thereby understand the degree to which delicacy is a learned performance rather than an innate feminine trait. Austens heroines display varying degrees of affectation of both modesty and sensibility through their performances of delicacy. These performances serve to highlight each heroines degree of modesty and sensibility, as well as to pique the interest ideally, although not always successfully of potential lovers. The performance of disability through delicacy is an essential feature of the temporary invalidism experienced by the heroines during the courtship narratives of Austens novels.

Signal detection theory predicts that costs associated with recognition errors, specifically failing to respond to relevant stimuli (missed detection) and responding to erroneous ones (false alarms), shape receiver permissiveness in animal communication systems. Fitness costs of missed detection and false alarms in response to sexual signals differ between the sexes, and are usually higher for females than males. This asymmetry in costs predicts that males should be more permissive than females in their responses to signals. In my dissertation I investigate the behavioral responses of male and female túngara frogs, Physalaemus pustulosus, to mating signals and sounds associated with such calls. Specifically I explore the following topics: i) responses of the sexes to call complexity, ii) perception of congeneric mating calls by males and females, iii) responses of males to the conspecific call compared to those of extant heterospecifics, iv) effect of sounds associated with increased predation risk in reproductive decisions, and v) effect of the task performed by each sex on signal permissiveness. My findings indicate that recognition errors are higher for males than females as predicted by the different costs associated with recognition errors for each sex. Males respond to a broader range of calls than females. Despite the differences, evolutionary history has left a footprint on the brain of both sexes. In addition, I found that females behaved more cautiously than males suggesting that the sexes balance the risk of predation and the cost of cautious mating strategies differently. In the mating system of túngara frog, as in many others, sexual signals elicit different tasks in the different sexes, female phonotaxis and male calling. Therefore, the sexual differences in decision making I found could be either sex-specific independent of task, or task-specific independent of sex. Here I show that sexual differences in receiver permissiveness are motivated by differences due to the typical reproductive tasks displayed by the sexes. / text

This project offers a multifaceted, interdisciplinary approach to understanding the contemporary post-Soviet Internet bride phenomenon and the rationales, motives, and aspirations of the industry's participants. As international marriage services have incorporated information and communications technologies (ICTs) to assist in the marketing of women of post-communist nations for correspondence courtship with Western men, the industry has furthered the globalization of marriage markets and the opportunities for communicative exchange among disparate nations and cultures. By way of case study, the project takes a special focus on the Belarusian/American segment of the industry, turning to personal interviews with participants and employing qualitative techniques to dissect marketing methods. The study gives primary consideration to processes and elements of globalization, postmodern consumer culture, and aspects of human sexuality (particularly sexual exchange theory), recognizing their interactive and mutually-constitutive nature that calls for their analysis through a Baudrillardian lens.

During the lifetime of an organism, key events are orchestrated by a confluence of environmental, social, and physiological factors to promote reproductive success. Steroid hormones are critical regulators of fundamental aspects of reproductive life history, including gametogenesis, secondary sexual characteristics, sexual behavior, territory establishment and defense, and parenting. The steroid hormones investigated herein (testosterone (T), 11-ketotestosterone (KT), 17b-estradiol (E2) and cortisol) are linked through steroidogenic conversion pathways. This dissertation utilized an integrative approach to investigate the neuroendocrine and social contexts that regulate transitions among phenotypes in a bi-directionally hermaphroditic haremic fish, Lythrypnus dalli. Conventional sex roles are reversed, such that only males provide nest care, females exhibit intra-sexual competition and male reproductive success is associated with female courtship solicitation. Females living in stable social groups maintain dramatic differences in status, morphology, and tissue T, KT, E2, and cortisol. Parasitic male morphs, mini males, do not defend territories and have morph-typical water-borne and tissue profiles of T, E2, and KT. Two life history transitions, socially induced sex change and male parenting, are associated with increase in rates of behavior and KT levels. The regulation of these life history transitions by KT was investigated via two types of endocrine manipulations. Coupling systemic KT implants with a social context permissive to sex change caused rapid, but transient effects on agonistic behavior in dominant females, and secondary effects on subordinates during a period of social instability. Despite elevated brain and systemic KT 5 d after implant, overall rates of aggressive behavior remained unaffected, demonstrating a key role for context in regulating steroid associated changes in behavior. Intracerebroventricular inhibition of the enzyme 11b-hydroxysteroid dehydrogenase, reduced KT, elevated cortisol, and reduced male parenting behavior. 11-Ketotestosterone rapidly rescued parenting when administered along with the inhibitor, while cortisol had no effects on parenting. During reduced male nest attendance caused by KT inhibition, dominant, but not subordinate females, exhibited transient parenting and elevated brain KT. Taken together, rapid and/or local modulation of steroids allows for context-specific regulation of dynamic changes in behavior in an environment that requires an organism to successfully coordinate multiple activities to enhance fitness.