Research on fruit fly courtship has mostly focused on males＇ behavioral repertoire whereas females have been as- sumed to respond by either rejecting or accepting males. In many fruit fly species including Drosophila...Research on fruit fly courtship has mostly focused on males＇ behavioral repertoire whereas females have been as- sumed to respond by either rejecting or accepting males. In many fruit fly species including Drosophila melanogaster, however, mating typically follows an extended period of courtship, which provides ample opportunities for females to inform males about their likelihood of mating. Our experiments indeed revealed that sexually immature females in both D. melanogasterand D. si- mulans showed responses to conspecific males that were distinct from those of sexually mature females. Furthermore, females＇ responses to conspecifie males were different from their responses to heterospecific males. Our data indicate that females＇ beha- vioral repertoire early in courtship can inform males about their probability of mating if they persist in courting. We hypothesize （i） that males can rely on behavioral feedback from females for optimally allocating their courtship efforts towards distinct female classes, （ii） that males may learn to modulate their courtship behavior based on specific feedback from females, and （iii） that fe- males may learn to alter their behavior towards distinct types of males in order to elicit the desired male response. Overall, we suggest that, although little explored, female behavior determines the dynamics of courtship and mating and can thus influence sexual selection and incipient speciation .展开更多
Mate-choice copying is a fascinating and widespread mate-choice strategy. Individuals gather public information about potential mates by observing others during sexual interactions and choose or reject the same indivi...Mate-choice copying is a fascinating and widespread mate-choice strategy. Individuals gather public information about potential mates by observing others during sexual interactions and choose or reject the same individual as a mate as the observed individual did before. The influence of copying behavior on an individual＇s mate choice can be so strong that socially acquired information can override genetically based preferences for certain phenotypes. Thus, mate-choice copying enforces dy- namic processes in sexual selection. Here, we review the current state of research on mate-choice copying and focus on sex-specific aspects. We present evidence that mate-choice copying can support the evolution of novel sexual ornaments, and we discuss potential costs of mate-choice copying when public information is not reliable. Moreover, we discuss the conflict faced by males that copy since mate-choice copying increases sperm competition. In conclusion we suggest interesting topics for future research in mate-choice copying .展开更多
Male-male competition and female mate choice may both play important roles in driving and maintaining reproductive isolation between species. When previously allopatric species come into secondary contact with each ot...Male-male competition and female mate choice may both play important roles in driving and maintaining reproductive isolation between species. When previously allopatric species come into secondary contact with each other due to introductions, they provide an opportunity to evaluate the identity and strength of reproductive isolating mechanisms. If reproductive isolation is not maintained, hybridization may occur. We examined how reproductive isolating mechanisms medi- ate hybridization between endemic populations of the Red River pupfish Cyprinodon rubrofluviati- lis and the recently introduced sheepshead minnow C. variegatus. In lab-based dominance trials, males of both species won the same number of competitions. However, male C. rubrofluviatilis that won competitions were more aggressive than C, variegatus winners, and more aggression was needed to win against competitor C. variagatus than allopatric C. rubrofluviatilis. Duration of fights also differed based on the relatedness of the competitor. In dichotomous mate choice trials, there were no conspecific or heterospecific preferences expressed by females of either species. Our findings that male-male aggression differs between closely and distantly related groups, but female choice does not suggest that male-male competition may be the more likely mechanism to impede gene flow in this system.展开更多
The term ＇assortative mating＇ has been applied to describe two very different phenomena： （1） the tendency for indi- viduals to choose phenotypically similar mates from among conspecifics; or （2） the tendency to...The term ＇assortative mating＇ has been applied to describe two very different phenomena： （1） the tendency for indi- viduals to choose phenotypically similar mates from among conspecifics; or （2） the tendency to prefer conspecific over hete- rospecific mates （behavioral reproductive isolation）. Both forms of assortative mating are widespread in nature, but the relation- ship between these behaviors remains unclear. Namely, it is plausible that a preference for phenotypically similar conspecifics in cidentally reduces the probability of mating with phenotypically divergent heterospecifics. We present a model to calculate how the level of reproductive isolation depends on intraspecific assortative mating and the phenotypic divergence between species. For empirically reasonable levels of intraspecific assortment on a single trait axis, we show that strong reproductive isolation requires very substantial phenotypic divergence. We illustrate this point by applying our model to empirical data from threespine stickleback Gasterosteus aculeatus and Darwin＇s Finches （Geospiza spp）. We conclude that typical levels of intraspecific assortment cannot generally be extrapolated to explain levels of interspecific reproductive isolation. Instead, reproductive isolation between species likely arises from different mate choice behaviors, or multivariate assortative mating [Current Zoology 58 （3）： 484-492, 2012].展开更多
Multidirectional communicative interactions in social networks can have a profound effect on mate choice behavior. Male Atlantic molly Poecilia mexicana exhibit weaker mating preferences when an audience male is prese...Multidirectional communicative interactions in social networks can have a profound effect on mate choice behavior. Male Atlantic molly Poecilia mexicana exhibit weaker mating preferences when an audience male is presented. This could be a male strategy to reduce sperm competition risk： interacting more equally with different females may be advantageous because ri- vals might copy mate choice decisions. In line with this hypothesis, a previous study found males to show a strong audience effect when being observed while exercising mate choice, but not when the rival was presented only before the choice tests. Audience effects on mate choice decisions have been quantified in poeciliid fishes using association preference designs, but it remains un- known if patterns found from measuring association times translate into actual mating behavior. Thus, we created five audience treatments simulating different forms of perceived sperm competition risk and determined focal males＇ mating preferences by scoring pre-mating （nipping） and mating behavior （gonopodial thrusting）. Nipping did not reflect the pattern that was found when association preferences were measured, while a very similar pattern was uncovered in thrusting behavior. The strongest response was observed when the audience could eavesdrop on the focal male＇s behavior. A reduction in the strength of focal males＇ preferences was also seen after the rival male had an opportunity to mate with the focal male＇s preferred mate. In comparison, the reduction of mating preferences in response to an audience was greater when measuring association times than actual mating behavior. While measuring direct sexual interactions between the focal male and both slimulus females not only the male＇s motivational state is reflected but also females＇ behavior such as avoidance of male sexual harassment [Current Zoology 58 （1）： 84-94, 2012].展开更多
Sexual isolation resulting from differences in mate choice behaviors is a hallmark of rapidly-speciating lineages. When present, asymmetrical sexual isolation may provide insights into the mechanisms responsible for t...Sexual isolation resulting from differences in mate choice behaviors is a hallmark of rapidly-speciating lineages. When present, asymmetrical sexual isolation may provide insights into the mechanisms responsible for the evolutionary change in mate signaling traits. In particular, Kaneshiro＇s hypothesis suggests that divergence in sexual characters between populations may arise in allopatry when ＇derived＇ founding populations are subject to severe population bottlenecks, accompanied by a relaxation of sexual selection relative to ＇ancestral＇ source populations. In the present study, we tested predictions of asymmetrical sexual isolation between two allopatric species of Hawaiian Laupala crickets, representing ＇ancestral＇ （L. makaio） and ＇derived＇ （L. nigra） taxa. While crickets in this genus are notable for rapid divergence of male courtship songs, these species share similar song types, thus suggesting that patterns of sexual isolation are likely due to other mating cues. Analysis of behavioral responses in conspeci- fic and heterospecific ＇no-choice＇ mating trials revealed pronounced asymmetrical isolation in the direction predicted by Kane- shiro＇s hypothesis, wherein we observed a significant reduction in mating success for crosses involving ＇derived＇ males paired with ＇ancestral＇ females, compared to the reciprocal heterospecific and both conspecific pairings. Further dissection of courtship behaviors suggested this difference did not reflect male mate choice, but rather, marked reduced spermatophore acceptance rates by ＇ancestral＇ females paired with ＇derived＇ males. The results are discussed with respect to founder effect models of speciatiou and the potential role of chemosensory signals in mate choice in these species [Current Zoology 59 （2）： 230-238, 2013].展开更多
文摘Research on fruit fly courtship has mostly focused on males＇ behavioral repertoire whereas females have been as- sumed to respond by either rejecting or accepting males. In many fruit fly species including Drosophila melanogaster, however, mating typically follows an extended period of courtship, which provides ample opportunities for females to inform males about their likelihood of mating. Our experiments indeed revealed that sexually immature females in both D. melanogasterand D. si- mulans showed responses to conspecific males that were distinct from those of sexually mature females. Furthermore, females＇ responses to conspecifie males were different from their responses to heterospecific males. Our data indicate that females＇ beha- vioral repertoire early in courtship can inform males about their probability of mating if they persist in courting. We hypothesize （i） that males can rely on behavioral feedback from females for optimally allocating their courtship efforts towards distinct female classes, （ii） that males may learn to modulate their courtship behavior based on specific feedback from females, and （iii） that fe- males may learn to alter their behavior towards distinct types of males in order to elicit the desired male response. Overall, we suggest that, although little explored, female behavior determines the dynamics of courtship and mating and can thus influence sexual selection and incipient speciation .
文摘Mate-choice copying is a fascinating and widespread mate-choice strategy. Individuals gather public information about potential mates by observing others during sexual interactions and choose or reject the same individual as a mate as the observed individual did before. The influence of copying behavior on an individual＇s mate choice can be so strong that socially acquired information can override genetically based preferences for certain phenotypes. Thus, mate-choice copying enforces dy- namic processes in sexual selection. Here, we review the current state of research on mate-choice copying and focus on sex-specific aspects. We present evidence that mate-choice copying can support the evolution of novel sexual ornaments, and we discuss potential costs of mate-choice copying when public information is not reliable. Moreover, we discuss the conflict faced by males that copy since mate-choice copying increases sperm competition. In conclusion we suggest interesting topics for future research in mate-choice copying .
文摘Male-male competition and female mate choice may both play important roles in driving and maintaining reproductive isolation between species. When previously allopatric species come into secondary contact with each other due to introductions, they provide an opportunity to evaluate the identity and strength of reproductive isolating mechanisms. If reproductive isolation is not maintained, hybridization may occur. We examined how reproductive isolating mechanisms medi- ate hybridization between endemic populations of the Red River pupfish Cyprinodon rubrofluviati- lis and the recently introduced sheepshead minnow C. variegatus. In lab-based dominance trials, males of both species won the same number of competitions. However, male C. rubrofluviatilis that won competitions were more aggressive than C, variegatus winners, and more aggression was needed to win against competitor C. variagatus than allopatric C. rubrofluviatilis. Duration of fights also differed based on the relatedness of the competitor. In dichotomous mate choice trials, there were no conspecific or heterospecific preferences expressed by females of either species. Our findings that male-male aggression differs between closely and distantly related groups, but female choice does not suggest that male-male competition may be the more likely mechanism to impede gene flow in this system.
文摘The term ＇assortative mating＇ has been applied to describe two very different phenomena： （1） the tendency for indi- viduals to choose phenotypically similar mates from among conspecifics; or （2） the tendency to prefer conspecific over hete- rospecific mates （behavioral reproductive isolation）. Both forms of assortative mating are widespread in nature, but the relation- ship between these behaviors remains unclear. Namely, it is plausible that a preference for phenotypically similar conspecifics in cidentally reduces the probability of mating with phenotypically divergent heterospecifics. We present a model to calculate how the level of reproductive isolation depends on intraspecific assortative mating and the phenotypic divergence between species. For empirically reasonable levels of intraspecific assortment on a single trait axis, we show that strong reproductive isolation requires very substantial phenotypic divergence. We illustrate this point by applying our model to empirical data from threespine stickleback Gasterosteus aculeatus and Darwin＇s Finches （Geospiza spp）. We conclude that typical levels of intraspecific assortment cannot generally be extrapolated to explain levels of interspecific reproductive isolation. Instead, reproductive isolation between species likely arises from different mate choice behaviors, or multivariate assortative mating [Current Zoology 58 （3）： 484-492, 2012].
文摘Multidirectional communicative interactions in social networks can have a profound effect on mate choice behavior. Male Atlantic molly Poecilia mexicana exhibit weaker mating preferences when an audience male is presented. This could be a male strategy to reduce sperm competition risk： interacting more equally with different females may be advantageous because ri- vals might copy mate choice decisions. In line with this hypothesis, a previous study found males to show a strong audience effect when being observed while exercising mate choice, but not when the rival was presented only before the choice tests. Audience effects on mate choice decisions have been quantified in poeciliid fishes using association preference designs, but it remains un- known if patterns found from measuring association times translate into actual mating behavior. Thus, we created five audience treatments simulating different forms of perceived sperm competition risk and determined focal males＇ mating preferences by scoring pre-mating （nipping） and mating behavior （gonopodial thrusting）. Nipping did not reflect the pattern that was found when association preferences were measured, while a very similar pattern was uncovered in thrusting behavior. The strongest response was observed when the audience could eavesdrop on the focal male＇s behavior. A reduction in the strength of focal males＇ preferences was also seen after the rival male had an opportunity to mate with the focal male＇s preferred mate. In comparison, the reduction of mating preferences in response to an audience was greater when measuring association times than actual mating behavior. While measuring direct sexual interactions between the focal male and both slimulus females not only the male＇s motivational state is reflected but also females＇ behavior such as avoidance of male sexual harassment [Current Zoology 58 （1）： 84-94, 2012].
文摘Sexual isolation resulting from differences in mate choice behaviors is a hallmark of rapidly-speciating lineages. When present, asymmetrical sexual isolation may provide insights into the mechanisms responsible for the evolutionary change in mate signaling traits. In particular, Kaneshiro＇s hypothesis suggests that divergence in sexual characters between populations may arise in allopatry when ＇derived＇ founding populations are subject to severe population bottlenecks, accompanied by a relaxation of sexual selection relative to ＇ancestral＇ source populations. In the present study, we tested predictions of asymmetrical sexual isolation between two allopatric species of Hawaiian Laupala crickets, representing ＇ancestral＇ （L. makaio） and ＇derived＇ （L. nigra） taxa. While crickets in this genus are notable for rapid divergence of male courtship songs, these species share similar song types, thus suggesting that patterns of sexual isolation are likely due to other mating cues. Analysis of behavioral responses in conspeci- fic and heterospecific ＇no-choice＇ mating trials revealed pronounced asymmetrical isolation in the direction predicted by Kane- shiro＇s hypothesis, wherein we observed a significant reduction in mating success for crosses involving ＇derived＇ males paired with ＇ancestral＇ females, compared to the reciprocal heterospecific and both conspecific pairings. Further dissection of courtship behaviors suggested this difference did not reflect male mate choice, but rather, marked reduced spermatophore acceptance rates by ＇ancestral＇ females paired with ＇derived＇ males. The results are discussed with respect to founder effect models of speciatiou and the potential role of chemosensory signals in mate choice in these species [Current Zoology 59 （2）： 230-238, 2013].
