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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

The influence of familial involvement and cultural values on mate preferences and romantic relationships : what do today's emerging adults in India and America want?

Bejanyan, Kathrine January 2015 (has links)
With increasing globalization, researchers are beginning to document the changing patterns of family life in collectivistic societies undergoing rapid economic development, such as India. With these changes, expectations of romantic relationships are also shifting as individuals re-calibrate their gender roles and attitudes towards romantic relationships to meet the challenges of modern society. Yet, not enough is known about the younger generation of collectivist youth and their evolving romantic habits and preferences. Therefore, the overarching goal of this thesis was to gain a more comprehensive understanding of cultural and familial influences in selecting a marital partner, maintaining a relationship, endorsing romantic beliefs, and anticipating future difficulties in marital life. In collectivist cultures, families tend to be characterized by respect for parental authority and strong, interdependent ties. Do these aspects of collectivism exert countervailing pressures on mate choices and relationship quality? In Study 1, I tested my predictions on a British sample by dividing participants into high or low collectivist groups based on their heritage cultural background, whereas in Study 2 I recruited participants from India and the United States. In both studies, I found that collectivism was associated with greater acceptance of parental influence over mate choice, thereby driving relationship commitment down, but collectivism was also associated with stronger family ties (referred to as family allocentrism), which drove commitment up (Study 2). Along similar lines, Study 1 found that collectivists’ greater acceptance of parental influence on mate choice contributed to their reduced relationship passion, whereas Study 2 found that their greater family allocentrism may have enhanced their passion. Study 2 also revealed that collectivists may have reported a smaller discrepancy between their own preferences for mates high in warmth and trustworthiness and their perception of their parents’ preferences for these qualities because of their stronger family allocentrism. However, their higher tolerance of parental V influence may have also contributed to a smaller discrepancy in their mate preferences versus their perceptions of their parents’ preferences for qualities signifying status and resources. Studies 3 and 4 moved away from familial dynamics and took a closer look at the cultural values of collectivism and gender role ideology. Previous studies have established that Indians tend to be greater in collectivism and gender role traditionalism than Americans. The purpose of Studies 3 and 4 was to examine whether these differences explained further cultural differences in romantic beliefs, traditional mate preferences, and anticipation of future difficulties in marital life. Results for both studies revealed that Indians reported greater collectivism than Americans and, in turn, held stronger romantic beliefs. Additionally, Indians’ greater collectivism, endorsement of more traditional gender roles and benevolent sexism in part predicted their preferences for a marital partner possessing traditional characteristics. Collectivism and gender role traditionalism accounted for Indians’ heightened concerns about encountering future difficulties in marital life in Study 3, while in Study 4 only collectivism explained these concerns. Overall, the results from these four studies shed light on the processes underlying cultural differences in relationship attitudes and preferences, and point to the need for greater cultural awareness and sensitivity to the diversity that exists in relationship functioning across societies.
22

Sexual Selection in Mantled Howling Monkeys (Alouatta palliata), With an Emphasis on the Role of Female Mate Choice

Ford, Randall Thomas January 2010 (has links)
<p>Despite early neglect, recent studies of sexual selection have shown a renewed interest in female reproductive strategies. Clearly the traditional portrayal of female animals as passive participants in mating is incorrect, but much is still unknown about female reproductive strategies, including the extent of female mate choice. The primary goal of this dissertation was to explore the role of female mate choice in mantled howling monkeys (<italic>Alouatta palliata</italic>), a species in which males have previously been assumed to control mating. </p><p>From March 2006 through February 2007, I used continuous focal-animal sampling to record the behavior of adult female mantled howlers at Hacienda La Pacifica, Guanacaste, Costa Rica. The focal animals in the study were nine adult females in a social group that has been regularly monitored since 1984. There were also three capture sessions performed by K. Glander to collect blood samples for genetic paternity analysis. A total of 29 individuals in the study group and eight adult males from surrounding groups were captured.</p><p>The genetic paternity analyses were largely inconclusive. Of the eight microsatellite markers used previously in this species, only four were polymorphic in this sample. Additionally, nearly half (7 of 16) of the purported mothers were excluded at one locus. Assuming the mother was unknown allowed determination of genetic paternity in only one case. In terms of behavior, females were largely responsible for soliciting copulations, but female mate choice did not appear to be a major factor. Females almost never rejected copulations (3.3% of copulation attempts) and mated with multiple males in 77.8% of female cycles. </p><p>The lack of conclusive genetic paternity data leaves open the possibility of post-copulatory female choice. However, explanations exist for the apparent lack of female mate choice in this species. Because males must attain alpha status to remain in a group, differences in inherent quality may be low among group males. The potential for small differences among males in a social group, combined with the fact that females disperse from their natal group, suggests that female mate choice may occur primarily in choosing a group during dispersal.</p> / Dissertation
23

Courtship acoustics and mating in Cotesia, a genus of parasitoid wasps

Joyce, Andrea Lee 15 May 2009 (has links)
Cotesia are parasitoid wasps (Hymenoptera: Braconidae) that are used for biological control of pest moths (Lepidoptera: Noctuidae, Pyralidae) that damage agricultural crops. This dissertation investigated courtship acoustics and mating, and their relevance to biological control, in members of the Cotesia flavipes species complex, and a noncomplex member, Cotesia marginiventris. The first study investigated whether courtship acoustics were species specific for two members of the Cotesia flavipes complex, C. flavipes and C. sesamiae, and for C. marginiventris. During courtship, male Cotesia fan their wings and produce low amplitude sounds and substrate vibrations. The airborne and substrate components of courtship were similar within a species. However, the courtship acoustics of each species was distinct. The duration and frequency of several courtship acoustic components distinguished each species, while some components did not differ among species. The second study investigated mating success and transmission of courtship vibrations on natural and artificial rearing substrates for Cotesia marginiventris. Mating success was measured on plastic, glass, corn and bean leaves, and chiffon fabric. Mating success was lowest on plastic and glass, intermediate on corn and bean leaves, and highest on chiffon. Substrate influenced transmission of courtship vibrations. Durations of courtship vibrations were longer on corn, bean and chiffon than on plastic. Frequency modulation occurred on corn, bean and chiffon, and amplitude was greatest on chiffon. The mating success of normal and dealated males was higher on chiffon than on glass, suggesting that courtship communication relied in part on substrate vibrations. The third study examined female and male mate choice in a solitary and a gregarious species, C. marginiventris and C. flavipes, respectively. Females of the solitary species, C. marginiventris, mated more frequently with large than small males, and this did not appear to be the result of male competition. Male choice for female size was not apparent in C. marginiventris. Females of the gregarious parasitoid, C. flavipes, mated with large or small males with similar frequencies, and male-male competition was not observed. In the male choice experiment, C. flavipes males attempted copulation and mated more with smaller females, and smaller females accepted males more than large females.
24

Mate choice and hybridization within swordtail fishes (Xiphophorus spp.) and wood warblers (family Parulidae)

Willis, Pamela Margaret 04 June 2012 (has links)
Behavioral isolation is an important barrier to gene flow, contributing to the formation and maintenance of animal species. Nevertheless, hybridization occurs more commonly than is generally recognized, occurring in over ten percent of animal species in the wild. Although the genetic consequences of hybridization are of considerable interest given their evolutionary implications, the reasons that animals choose to mate with other species are less clear. I apply mate choice theory to the question of hybridization, using wood warblers (family Parulidae) and swordtail fishes (genus Xiphophorus) as study systems. Over half of the 45 species of North American wood warbler have produced hybrids. Using comparative methods, I address the questions: Do ecological and demographic factors predict hybridization in this family? Similarly, how do phylogeny, song similarity, and sympatry with congeners correlate with hybridization? As with North American wood warblers, behavioral isolation is also considered of primary importance in isolating sympatric species of swordtail fishes. Two species, X. birchmanni and X. malinche, hybridize in several locations in the wild. Through experimentation with these and other Xiphophorus species, I investigate some of the factors that cause female mate choice to vary, possibly contributing to hybridization. Specifically, I address the following questions: Do females become less choosy when predation risk is high, or encounter rates with conspecifics are low? Are female preferences for conspecifics innate, or can they be modified by experience? And, do female preferences for conspecifics vary among species, populations, or experiments? These studies illustrate the utility of treating hybridization as just another possible outcome of variation in mate choice. I find that warbler hybridization correlates with ecological and other variables, that female swordtails become more responsive to heterospecifics when mate choice is costly, and that female preferences for conspecifics are species- and context-dependent. As animal hybridization can have important evolutionary consequences, studying the factors that contribute to this variation can enhance our understanding of the evolutionary process. / text
25

Stratification in the Early Stages of Mate Choice

Lewis, Kevin January 2012 (has links)
Sociologists have long studied mate choice patterns to understand the shape of stratification systems. Romantic pairing involves intimacy and trust, and is therefore a prime indicator of the extent to which members of different social groupings (race/ethnicity, social class, education, religion) accept each other as social equals. The majority of this literature focuses on marriage, given the commitment marriage implies and the availability of nationally-representative data. In this dissertation, I examine the opposite end of the relationship spectrum: The initial screening and sorting process whereby strangers consider each other as potential mates; express interest in some subset of this population but not others; and find that this interest is or is not reciprocated. This beginning stage in mate choice is particularly important for our understanding of social boundaries because personality factors are likely to matter less and social characteristics to matter more. Yet because these initial forays into relationships are typically unobserved, we know very little about whom people consider as potential mates in the first place. I ask the following questions, corresponding to three empirical chapters: First, how do individuals from different status backgrounds vary in the types of strategies that they pursue and the degree of success that they achieve? Second, what underlying dynamics of homophily, competition, and gender asymmetry give rise to observed patterns of interaction, and under what circumstances do some of these boundaries break down? Third, how do strategies as well as preferences vary at different stages of selection, and at what point is homogeneity created? To answer these questions, I use detailed longitudinal data from a popular online dating site. These data are particularly useful for the study of social inequality not only due to the unique quantity and nature of information that is available, but also because online dating has become one of the primary ways that singles meet and marry today. / Sociology
26

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

Oh, Kevin January 2009 (has links)
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.
27

FEMALE REACTION TO MALE URINE SCENTS AS POTENTIAL INDICATOR OF MATE CHOICE IN CAPTIVE CHEETAHS (ACINONYX JUBATUS)

Mossotti, Regina Helen 01 May 2010 (has links)
AN ABSTRACT OF THE THESIS OF REGINA HELEN MOSSOTTI, for the Master of Science degree in ZOOLOGY, presented 23 October 2009, at Southern Illinois University Carbondale. TITLE: FEMALE REACTION TO MALE URINE SCENTS AS POTENTIAL INDICATOR OF MATE CHOICE IN CAPTIVE CHEETAHS (ACINONYX JUBATUS) MAJOR PROFESSOR: GEORGE A. FELDHAMER Genetic variation in the cheetah (Acinonyx jubatus) has become dangerously low because of dramatic population decline and fragmentation. Zoos throughout the world manage captive cheetahs with breeding programs to maximize genetic heterozygosity. Unfortunately, the zoo community has not accomplished consistent breeding success with cheetahs, possibly because of a general lack of information on sociosexual behavior. Currently, individual cheetahs are assigned mates based primarily on genetic relatedness; however, evidence from many species suggests that allowing animals to choose mates increases breeding success. When animals, primarily females, are allowed to choose mates they will often pick the best genetic match. I tested whether female cheetahs can determine their genetic relatedness to males by investigating their urine scents. Voided male urine was collected following scent marking. The female was offered scents from three different males: one from an unrelated male, a "good" mate choice (A), another from a male that was equivalent to a second cousin, an "average" mate choice (B), and one from a male that was closely related, equivalent to a brother/father, a "poor" mate choice (C). Every female was also offered "blank" gauze as a control (D). The scents were offered in a pair-wise forced choice paradigm for a total of six possible combinations. All behaviors displayed toward each scent (and their duration) were recorded. The estrous cycling of each female was monitored through fecal hormone evaluation for approximately six weeks, including the weeks during scent trials. In every pairing except C vs. D, the females spent more time overall with the better mate choice in the pair; with three of the comparisons being significantly different (A>C, t=2.38, df=11, P=0.039; A>D, t=1.88, df=11, P= 0.087 and B>D, t=2.62, df=8, P=0.045). Proximity was the most frequently observed behavior and females spent more time in proximity to the most distantly related male scent in all pairings. They spent significantly more time in proximity with A in AC pairing (t=2.25, df=10, P=0.049) and with B in the BC and BD pairings (t=6.37, df=8, P=0.0002; t=2.46, df=6, P=0.049; respectively). Sniffing was the next most frequently observed behavior, and in all pairings (except CD) females spent more time sniffing the most distantly related male's scent; but was only significantly different for A in the AD pairing (t=2.31, df=7, P=0.055). Lag time of estradiol in fecal samples varies between individuals; therefore, the affect of daily estradiol concentrations on scent choices could not be determined. This is the first mate choice study using urine with a mammalian carnivore.
28

Genetic architecture and ecological speciation in Heliconius butterflies

Merrill, Richard January 2013 (has links)
It is now widely accepted that adaptation to different ecological niches can result in the evolution of new species. However, when gene flow persists speciation must overcome the antagonism between selection and recombination: Specifically, if gene flow persists, recombination will break down the genetic associations between alleles that characterise emerging species and cause reproductive isolation. Accordingly, genetic architectures that impede recombination can slow the breakdown of linkage disequilibrium and facilitate speciation. Mimicry in tropical butterflies has long been championed as an example of adaptation driving speciation. In the Neotropical genus Heliconius, distantly related pairs of unpalatable species often converge on the same bright warning-pattern to more efficiently advertise their distastefulness to predators. In contrast, closely related taxa often belong to different mimicry rings. The sister species, Heliconius melpomene and H. cydno are sympatric across much of Central and northern South America. Using artificial butterflies I reveal selection against non-mimetic hybrid colour patterns between these two species. These colour patterns are also used as mating cues and mimetic shifts may cause both pre-mating and post-mating isolation. However, shifts in colour pattern cannot drive reproductive isolation alone; rather, they must be accompanied by corresponding mate preferences. Associations between trait and preference loci may be broken down by mating and subsequent recombination. I demonstrate a genetic linkage between loci for both male and female mate preference and wing colour pattern in Heliconius cydno and H. melpomene. In addition, I present evidence for further associations between alleles affecting hybrid sterility and host-plant use and colour pattern loci. All this implies that linkage between traits that contribute to reproductive and ecological isolation is a general phenomenon in Heliconius with an underlying adaptive basis. Overall these results expose a genetic mechanism that, by impeding recombination, can facilitate speciation in the face of gene flow.
29

Vliv polymorfismu Toll-like receptoru 4 na kondici a ornamentaci u sýkory koňadry / Vliv polymorfismu Toll-like receptoru 4 na kondici a ornamentaci u sýkory koňadry

Bainová, Hana January 2011 (has links)
Host-parasite co-evolution belongs to the most important evolutionary relationships that shape natural and sexual selection. Parasites pose permanent selective pressure on their hosts. Toll-like receptors (TLRs) as a part of innate immunity are involved in mechanisms of a first immunological barrier which has to be overcome by parasites. These receptors play a key role in primary detection of pathogen-associated molecular patterns (PAMPs) and, hence, are responsible for early triggering of effector immunological mechanisms and for co- activating adaptive immunity. Several studies revealed that TLR4 may represent a suitable model molecule for host-parasite co-evolution studies. TLR4 interacts directly with several PAMPs and structural variability in this receptor was shown to affect host resistance to various diseases. Thus, there is potential for occurrence of parasite-mediated natural and sexual selection. Contrary to the number of fish and mammalian TLRs described, avian inter- and intraspecific TLR variability is only very insufficiently explored. This is especially true for passerine birds. In my diploma thesis I therefore provide the first description of the complete Tlr4 translated region in a non-model free-living bird, great tit (Parus major), predict structure of the protein product of...
30

The role of context and comparative evaluation in female mate choice decisions of Schizocosa ocreata Hentz

Galbraith, Emily Logan 22 September 2008 (has links)
No description available.

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