Ecological speciation involves the evolution of reproductive isolation (RI) as a by-product of adaptation to different selective environments. Parallel patterns of non-random mating by environment type provide strong evidence that ecological speciation has occurred. The processes involved in the origins of RI are more difficult to detect however. One mechanism involves the correlated evolution of mating preferences and sexually selected traits. I developed a conceptual model for detecting RI under various scenarios of mate preference evolution. The model predicts that RI will not evolve if preferences are evolutionarily constrained relative to the preferred traits, but is detectable as long as preferences evolve in parallel. I then applied this framework to an empirical system with populations of guppies (Poecilia reticulata) adapted to low- and high-predation environments. I measured female mate preferences for male colour and size; traits which are divergent between the two environment types. Preference functions for colour also diverged in the predicted direction. The parallel pattern of preference divergence suggests that divergent natural selection from predators may be contributing to RI between guppy populations.

Orientador: Woodruff Whitman Benson / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-19T03:31:05Z (GMT). No. of bitstreams: 1 Carvalho_MarcioRomeroMarques_M.pdf: 919432 bytes, checksum: 1f0c159d8e11e0b88a3a120ac6ec0675 (MD5) Previous issue date: 2011 / Resumo: Os machos de várias espécies de borboletas defendem territórios de acasalamentos contra rivais da mesma espécie por meio de intensas perseguições em espirais. Tais perseguições raramente apresentam contato físico, tornando incerto como residentes obtêm vantagem territorial. No sudeste do Brasil os machos da borboleta aposemática Actinote pellenea (Nymphalidae), entretanto, defendem territórios agarrando rivais em vôo e caindo no solo em combate, indicando neste caso uma função da força física. Eu observei machos marcados de A. pellenea nos territórios com o objetivo de descrever as disputas em relação à natureza dos comportamentos, horário de ocorrência, e seus resultados. Analisei se injúrias físicas ocorreram e quais características dos machos, tais como tamanho, massa corporal, e desgaste alar (idade) poderiam relacionar-se com vitória em disputas. Avaliei o sucesso reprodutivo de machos donos de territórios (residentes) e machos sem territórios (intrusos) com base no número de cópulas realizadas por cada grupo. Realizei um experimento para analisar se a condição residente confere aos machos vantagem em vencer disputas, para isto, organizei disputas entre machos residentes previamente presos contra substitutos (intrusos) que naturalmente estabeleceram-se sobre o território vago (durante no mínimo 15 minutos). Os machos de A. pellenea começaram a defender territórios por volta das 9 h e permaneceram até aproximadamente 15:30 h. A maioria das disputas foram perseguições sem espirais (n=435; 84,3%), porém em muitas houve contatos físicos em que os rivais agarraram-se e soltaram-se no ar (n=25; 4,8%), e em que o rivais caíram no chão e lutaram (n=56; 10,8%). Danos nas asas foram arranhões com as garras, perda de escamas e em um caso perda de pedaços das asas. Os machos residentes (n=6) obtiveram mais acasalamentos do que os machos intrusos (n=2). Residentes venceram todas as disputas naturais contra intrusos, e não houve diferença de tamanho, peso ou desgaste alar de vencedores e perdedores de disputas. No experimento, residentes originais venceram 7 das 8 disputas contra residentes substitutos (intrusos). O consistente sucesso de residentes estabelecidos em territórios, até mesmo contra substitutos que aparecem durante breves ausências, sugerem que outros fatores motivacionais ou traços físicos não representados em nossas medidas são provavelmente responsáveis pelo sucesso deles em manter territórios / Abstract: The males of many butterfly species defend mating territories against conspecific rivals through intense spiraling chases. Such chases have practically no physical contact, making it unclear how residents obtain their territorial advantage. In southeastern of Brazil males of the aposematic butterfly Actinote pellenea (Nymphalidae), however, defend by seizing rivals in flight and dropping to the ground in combat, suggesting in this case a role for physical strength. I observed marked A. pellenea males at territory sites with the objective of describing contests regarding nature of contests, hours of occurrence, and their outcomes. I analyzed if physical injuries occurred and which traits such as size, body mass and wing wear (age) could relate to win contests. I evaluated the reproductive success of owner territories males (residents) and without territories males (intruders) based on number of the matings performed by each group. I realized an experiment to analyze if resident status gives to males advantage to win contests, for this, I arranged contests between resident males previously imprisoned against substitutes (intruders) that naturally settled over vacant territory (for at least 15 minutes). The males of A. pellenea began to defend territories arround for 9 h and stayed until nearly 15:30 h. The most contests were non-spiral chases (n=435; 84,3%), however in several had physical contact that rivals seized and release in the air (n=25; 4,8%), and that rivals fell on the ground and fought (n=56; 10,8%). Wings injuries were claw punctures, scales loss and one case pieces wings loss. The residents males (n=6) had more matings than intruders males (n=2). Residents won all natural contests against intruders, but there was no difference in size, body mass and wing wear between winners and losers of contests. In experiment original residents won 7 of 8 contests against substitutes residents (intruders). The consistent success of established territory residents, even against substitutes appearing during brief absences, suggests that either motivational factors or physical traits not represented in our measurements are likely responsible for their success in holding territories / Mestrado / Ecologia / Mestre em Ecologia

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Sexual selection arises via competition for access to mates, and is thus intimately tied to the social environment. For example, individual mating success may depend strongly on how many rivals or mating partners are available. Studies of mate choice and sexual selection may vary the number of mates a subject is presented with during mating experiments, yet it is not clear how this influences the strength and shape of sexual selection acting on traits in either sex. In this thesis I investigate the effect of social environment on sexual selection acting in two closely-related species of lygaeid seed bug: Lygaeus equestris and Lygaeus simulans. Males in both species possess an extremely elongate intromittent organ, which is over two-thirds average male body length. I show that the strength of pre-copulatory selection acting on male processus length in Lygaeus equestris and genital clasper shape in Lygaeus simulans is significantly influenced by the social context. However, selection on male and female body size in Lygaeus equestris is not. Additionally, I use a meta-analysis of 38 published studies to show that mating preferences are significantly stronger when more than one mate option is available, compared to when only a single option is available. I also investigate the functional morphology of male genital traits in Lygaeus simulans, and use formal selection analysis to quantify the strength of selection acting on these traits before, during and after mating. Finally, I use experimental manipulations in Lygaeus simulans to confirm that male processus length directly influences sperm transfer, and that intact genital claspers are required for successful intromission. Overall, my results illustrate that sexual selection in the wild may vary both spatially and temporally depending on the social environment. It is thus especially important that experiments are performed under ecologically relevant conditions.

Within the evolutionary framework of sexual selection and parental investment theory, the study employed four experiments to examine the effects of mating and parenting awareness on the perception and assessment of high risk sports. In Study 1, participants were exposed, in random order, five types of pictures---attractive female, regular female, attractive male, regular male, and award winning pictures. After the activation of each of these pictures, participants were asked to respond to pictures depicting high risk sport events. The reaction time to high risk sport events was shortest when men saw attractive female pictures. The same effect was not found in female participants viewing attractive male pictures. Study 2 used the same mating awareness manipulation (attractive female pictures versus other pictures) but also added parenting and child rearing pictures depicting pregnant women or young children with their mothers. The results showed that men's reaction time to high risk sports was shorter when exposed to attractive female pictures than other conditions and was longer when exposed to parenting-related pictures. Study 3 included socialsexual orientation as a covariate and results similar to Study 1 were obtained after controlling for the extraneous influence of socialsexual orientation. Study 4 focused on risk assessment in different domains including entertainment, financial investment, health and social risk. The results showed that men under-assessed risk in the entertainment domain when exposed to attractive female pictures than to award winning pictures. However, the same effect was not found with other risk domains. Overall, the findings support the evolutionary account of risk taking which is sexually selected male attribute as an ornament to attract mating partners and which is reduced when men shift from mating to parenting and child rearing concerns. One practical implication for controlling risk taking behaviors among adolescents is the knowledge that risk taking behavior may be more likely in mixed- than in single-gender social groups. / 李宏利. / Adviser: Lei Chang. / Source: Dissertation Abstracts International, Volume: 70-06, Section: A, page: 1923. / Thesis (doctoral)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (p. 93-118). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in Chinese and English. / School code: 1307. / Li Hongli.

Successful captive-breeding and re-introduction programs must have the ability to breed a surplus of genetically suitable animals for release into the wild. Unfortunately, many individuals in captive breeding programs often do not reproduce even when they are apparently healthy and presented with genetically appropriate mates. Mate choice can affect multiple parameters of reproductive sperformance, including mating success, offspring production, survival, and fecundity. We investigated the role of mate preference and personality on the reproductive performance of male and female giant pandas (Ailuropoda melanoleuca) as measured by intromission success and litter production. We conducted these studies on giant pandas at the China Conservation and Research Center for the Giant Panda (Bifengxia, Sichuan, China.) from February-May 2011, 2012, and 2013. In Chapter 2, we compared reproductive performance between individuals mated with preferred and nonpreferred males of the focal female (female preference), the focal male (male preference), and mutual mate choice perspective. There were four types of reproductive pairings in our mutual mate choice analyses: females and males that preferred each other (P-P), females that preferred the male but the male did not prefer the female (P-NP), females that did not prefer the male but the male preferred the female (NP-P), and females and males that did not prefer each other (NP-NP). Pairing giant pandas with a preferred partner increased the probability of intromission success and producing a cub. Of the 25 females mated to a preferred partner, 72% had successful intromission, 64% produced cubs, and 52% reared their own cubs versus 31%, 12%, 12% for females mated to their nonpreferred partner (N = 16). Male giant panda mate preference showed similar results. Of the 24 males that were mated with their preferred females, 75% had successful intromission, 77.8% produced cubs, and 92.9% produced cubs that were maternally reared versus 31%, 60%, 66.7% for males mated with their nonpreferred females (N = 16). There was a statistically significant difference in intromission success and cub production for P-P pairings versus NP-NP pairings. Of the twelve P-P mate dyads 83% had successful intromission, 90% produced cubs, and 88.9% had mothers rear their cubs. Of the four P-NP mate dyads 50% had successful intromission, 50% produced cubs, and 100% had the mother rear their cub. Of the seven NP-P mate dyads 57% had successful intromission, 50% produced cubs, and 100% had the mothers rear their cubs. Of the three NP-NP mate dyads 0% had successful intromission resulting in 0% producing cubs and having mother-rear cubs. In addition, we took into account various life and breeding history factors that may have affected reproductive performance such as birth location, rearing, previous sexual history with the opposite sex and familiarity status directly prior to breeding. Mate pairings that were familiar with each other as measured by successfully producing a cub in the past, had increased intromission success. Females mated to heavier males had more intromissions and produced more cubs than females mated to smaller males. In Chapter 3 and 4, we investigated the effect of personality on reproductive performance measurements. Recently, personality of individual animals has been implicated in the failure or success of captive management and breeding of threatened and endangered species. Measurements of personality included novel object tests (where behaviors of individual giant pandas were scored toward a novel object for one hour) and keeper surveys (where the primary keeper rated giant pandas on 23 adjectives describing personality); both measures significantly correlated with variation in long-term and specific mating dyad reproductive performance. In Chapter 3 we evaluated the effect of personality on long-term reproductive performance. Our results show that for both male and female giant pandas, `fearful' individuals had lower natural mating success and cub production. In addition, `aggressive' female giant pandas had increased natural mating success but decreased cub production. Males did not show these relationships between `aggressive' personality types and reproductive performance. Female giant pandas that were labeled as `aggressive' had higher frequencies of positive mating behaviors but `fearful of conspecifics' females had lower frequencies. Males labeled `fearful of conspecifics' and with high `playful-clever' component scores had a lower frequency of positive mating behaviors. In Chapter 4 we further investigated the effects of personality within a specific mating dyad. Recent studies suggest that mate compatibility within personality types can improve reproductive performance measurements such as mating success, offspring survivorship, and offspring quality. We investigated the effect of personality compatibility on reproductive performance through analyzing mate dyad similarity in personality (similar versus dissimilar), specific personality combinations, and relative personality scores (male scores higher or lower than female scores). The specific personality combinations were: females and males that were both low on the personality component (L_L), females were low but males were high (L_H), females were high but males were low (H_L), and females and males were both high (H_H). Our results suggest that giant pandas appear to be assortatively mating based on aggressive, fearful, and stereotypical-excitable personality traits. Mate dyads that were dissimilar on the stereotypical-excitable component score were more likely to have successful intromission than pairs that were similar. L_H mate dyads on the aggressive and stereotypical-excitable personality traits had increased intromission success and cub production than all other possible personality combinations. L_L on fearfulness had higher intromission success but not higher cub production than all other possible personality combinations. Mate dyads composed of males ranked high on the aggressive component relative to the female resulted in higher reproductive performance and cub production. In captive breeding programs, mates are traditionally selected solely on the basis of genetic parameters to minimize loss of genetic diversity and inbreeding coefficients. Our results suggest that integrating genetic with behavioral measures of preference, breeding history factors, and personality would increase the reproductive output of the giant panda captive-breeding program. We stress the importance of considering husbandry practices to accommodate personality traits and ultimately increase reproductive performance in the captive population while simultaneously maintaining both genetic and behavioral diversity.

For humans and non-human primates (NHPs) the face represents a particularly important source of social information providing a means of conspecific recognition and cues to personal details including sex, age, and emotional state. The human face may also be fundamental in the transmission to conspecifics of other forms of socially relevant information including the display of facial traits associated with sexual attraction and mate choice. A wealth of experimental literature indicates that humans display robust preferences for certain facial traits associated with facial attractiveness including preferences for bilateral facial symmetry, facial averageness and sexually dimorphic faces and facial features. It is thought that these preferences have evolved via sexual selection, and may be adaptive, due to the role that these specific facial features play in reliably signalling to others the possession of heritable genetic quality or ‘good genes’. Therefore, from an evolutionary perspective, it is possible that certain facial preferences may represent an evolutionary adaptation for the selection of potential mate quality. However, despite similarities between human and NHP face processing and recognition abilities, the shared evolutionary history and social importance of faces to primates in general, and the potential importance of these preferences in the mate choice decisions of NHPs, very little research has investigated the extent to which NHPs display comparable preferences to humans for these specific facial traits. Consequently, the aim of the following thesis was to comparatively assess the general and more specific preferences that humans and NHPs display for faces and for traits associated with facial attractiveness. Data was compiled from preference studies examining the visual preferences displayed by two species of NHP (brown capuchins (Cebus apella) and chimpanzees (Pan troglodytes)) for conspecific faces manipulated for those facial traits associated with attractiveness, and from a single study of brown capuchins examining their general visual preferences for various types of facial information. Comparative preference studies were also conducted upon human adults and infants examining the visual and declared preferences that they display for manipulations of facial attractiveness. Data showed that despite possessing general preferences for certain faces and facial information, generally NHPs displayed no significant preferences for those facial traits thought to influences judgements of attractiveness in humans. Possible reasons for this absence of preference for these particular facial traits and the evolutionary implications of these findings are discussed.

The aim of this study was to investigate the basis to male mating decisions in two related species of bitterling: Rhodeus ocellatus and R. amarus. Bitterling have a resource-based mating system; females lay eggs in the gills of live freshwater mussels and males fertilize the eggs by releasing sperm into the inhalant syphon of the mussel. Male bitterling perform courtship behaviour and aggressively defend mussels in a territory from which they exclude other males. Using laboratory and field experiments it was shown that male aggressive behaviour is inherited through additive maternal genes. Male aggression is also influenced by the number of conspecific males encountered in competition for a mussel, and by the degree of clustering of mussels. Limited availability of mussels results in stronger selection on traits males use in mating context: hence they are more aggressive, larger and more colourful. The differences in mating behaviours in different environments may indicate a conflict between male dominance and female choice, but have not led to reproductive isolation. Resource availability during ontogenesis and male density during embryogenesis, however, do not exert an effect on male aggressive behaviour. Red carotenoid-based nuptial coloration functions as an inter- and intra-sexual signal and undergoes rapid variation in response to changes in mating context. Male bitterling do not modulate their courtship and aggressive behaviour in response to variation in female size, and their choice of mussel species is influenced by, and consistent with, female oviposition choice.

Thesis (Ph. D.)--Miami University, Dept. of Zoology, 2003. / Title from second page of PDF document. Includes bibliographical references.

Sexual selection is considered a powerful evolutionary force responsible for the enormous diversity found in reproductive morphology, physiology, and behavior. I addressed questions related to selection in the Cape ground squirrel (Xerus inauris), a species characterized as highly social and promiscuous. These attributes often are responsible for variance in male reproductive success and as such, sexual selection theory predicts increased opportunity for sexual selection. I confirm that the predominant mechanism underlying genital evolution and competition for paternity in X. inauris is sperm competition. I find evidence that investment in sperm competition is costly and may reflect immunocompetence. I quantify reproductive success as it relates to alternative male tactics and female resource distribution. I find that male X. inauris alternative reproductive tactics differ within and across populations most likely due to differences in female resource distribution. In areas where females are evenly distributed, dispersed males encounter more estrous females, and therefore have increased breeding opportunities. However, the decision to remain natal does not preclude reproduction. I determine that these tactics are most likely conditional with equal fitness payoffs. Males, regardless of tactic, invest more in post-copulatory competition (e.g. sperm competition, copulatory plugs) than males within a population with a clustered distribution of breeding females. In the latter area, males form dominance hierarchies that affect copulatory success and lead to greater skews in reproduction among males. Both sites have evidence of a highly skewed variance in reproduction and intense sexual selective pressure. My results suggest these populations have increased opportunities for selection but that different mechanisms of intrasexual competition may result in rapid evolutionary change within this species.