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Tracey Chapman - One of the best experts on this subject based on the ideXlab platform.
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variation in adult sex ratio alters the association between courtship Mating Frequency and paternity in the lek forming fruitfly ceratitis capitata
Journal of Evolutionary Biology, 2012Co-Authors: Philip T Leftwich, Dominic A Edward, Luke Alphey, Matthew J G Gage, Tracey ChapmanAbstract:The intensity with which males deliver courtship and the Frequency with which they mate are key components of male reproductive success. However, we expect the strength of the relationship between these traits and a male’s overall paternity to be strongly context dependent, for example to be altered significantly by the extent of post-Mating competition. We tested this prediction in a lekking insect, Ceratitis capitata (medfly). We examined the effect of manipulating the sex ratio from male- to female-biased (high and low male competition, respectively) on courtship behaviour, Mating Frequency and paternity of focal males. Under high male competition, focal males delivered significantly more courtship but gained lower paternity than under lower competition. Paternity was positively associated with Mating Frequency and small residual testes size. However, the association between Mating Frequency and paternity was significantly stronger under low competition. We conclude that manipulation of sex ratio significantly altered the predictors of Mating success and paternity. The relationship between pre- and post-Mating success is therefore plastic and alters according to the prevailing level of competition. The results highlight the importance of post-copulatory processes in lekking species and illuminate selection pressures placed on insects such as medflies that are mass reared for pest control.
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Mating induced reduction in accessory reproductive organ size in the stalk eyed fly cyrtodiopsis dalmanni
BMC Evolutionary Biology, 2005Co-Authors: David W Rogers, Tracey Chapman, Kevin Fowler, Andrew PomiankowskiAbstract:Internal reproductive organ size is an important determinant of male reproductive success. While the response of testis length to variation in the intensity of sperm competition is well documented across many taxa, few studies address the importance of testis size in determining other components of male reproductive success (such as Mating Frequency) or the significance of size variation in accessory reproductive organs. Accessory gland length, but not testis length, is both phenotypically and genetically correlated with male Mating Frequency in the stalk-eyed fly Cyrtodiopsis dalmanni. Here we directly manipulate male Mating status to investigate the effect of copulation on the size of both the testes and the accessory glands of C. dalmanni. Accessory gland length was positively correlated with male Mating Frequency. Copulation induced a significant decrease in accessory gland size. The size of the accessory glands then recovered slowly over the next 8–48 hours. Neither testis length nor testis area was altered by copulation. These results reveal that the time course of accessory gland recovery corresponds to field observations of Mating behaviour and suggest that accessory gland size may limit male Mating Frequency in C. dalmanni.
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female resistance to male harm evolves in response to manipulation of sexual conflict
Evolution, 2004Co-Authors: Stuart Wigby, Tracey ChapmanAbstract:The interests of males and females over reproduction rarely coincide and conflicts between the sexes over mate choice, Mating Frequency, reproductive investment, and parental care are common in many taxa. In Drosophila melanogaster, the optimum Mating Frequency is higher for males than it is for females. Furthermore, females that mate at high frequencies suffer significant Mating costs due to the actions of male seminal fluid proteins. Sexual conflict is predicted to lead to sexually antagonistic coevolution, in which selection for adaptations that benefit males but harm females is balanced by counterselection in females to minimize the extent of male-induced harm. We tested the prediction that elevated sexual conflict should select for increased female resistance to male-induced harm and vice versa. We manipulated the intensity of sexual conflict by experimentally altering adult sex ratio. We created replicated lines of D. melanogaster in which the adult sex ratio was male biased (high conflict lines), equal (intermediate conflict lines), or female biased (low conflict lines). As predicted, females from high sexual conflict lines lived significantly longer in the presence of males than did females from low conflict lines. Our conclusion that the evolutionary response in females was to the level of male-induced harm is supported by the finding that there were no female longevity differences in the absence of males. Differences between males in female harming ability were not detected. This suggests that the response in females was to differences between selection treatments in Mating Frequency, and not to differences in male harmfulness.
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accessory gland size influences time to sexual maturity and Mating Frequency in the stalk eyed fly cyrtodiopsis dalmanni
Behavioral Ecology, 2003Co-Authors: Richard Baker, Kevin Fowler, Andrew Pomiankowski, Matthew Denniff, Peter Futerman, Tracey ChapmanAbstract:Age at first reproduction is an extremely important life-history trait. Several factors such as nutritional state and age-specific fecundity have been shown to influence time to sexual maturity; however, little work has been done in insects. We addressed this in a stalk-eyed fly (Cyrtodiopsis dalmanni), by testing the hypothesis that time to sexual maturity is associated with the development of male internal reproductive structures. We found that sexual maturity was attained after an increased rate of growth in the accessory glands, several days after mature sperm bundles, and motile sperm were observed in the testes. Although testis development is essential, the results suggest that accessory gland growth is more closely associated with the time taken to reach sexual maturity than is testis growth. When we manipulated the growth of testes and accessory glands via a dietary manipulation, we found that delayed growth rates increased the time taken to reach sexual maturity. Among the delayed individuals, sexually mature males had larger accessory glands, but not testes, than did immature males. In adult males, Mating Frequency was significantly positively correlated with accessory gland size, but not with testis length or body size. We conclude that accessory gland size is a critical determinant of sexual maturity and male Mating Frequency in this species.
Jacobus J Boomsma - One of the best experts on this subject based on the ideXlab platform.
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extreme queen Mating Frequency and colony fission in african army ants
Molecular Ecology, 2004Co-Authors: Jes S Pedersen, Jacobus J Boomsma, Daniel J C Kronauer, Caspar Schoning, Jurgen GadauAbstract:Army ants have long been suspected to represent an independent origin of multiple queenMating in the social Hymenoptera. Using microsatellite markers, we show that queens of the African army ant Dorylus ( Anomma ) molestus have the highest absolute (17.3) and effective (17.5) queen-Mating frequencies reported so far for ants. This confirms that obligate multiple queen-Mating in social insects is associated with large colony size and advanced social organization, but also raises several novel questions. First, these high estimates place army ants in the range of Mating frequencies of honeybees, which have so far been regarded as odd exceptions within the social Hymenoptera. Army ants and honeybees are fundamentally different in morphology and life history, but are the only social insects known that combine obligate multiple Mating with reproduction by colony fission and extremely male-biased sex ratios. This implies that the very high numbers of Matings in both groups may be due partly to the relatively low costs of additional Matings. Second, we were able to trace recent events of colony fission in four of the investigated colonies, where the genotypes of the two queens were only compatible with a mother–daughter relationship. A direct comparison of male production between colonies with offspring from one and two queens, respectively, suggested strongly that new queens do not produce a sexual brood until all workers of the old queen have died, which is consistent with kin selection theory.
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male reproductive investment and queen Mating Frequency in fungus growing ants
Behavioral Ecology, 2004Co-Authors: Boris Baer, Jacobus J BoomsmaAbstract:Sperm number and male accessory gland compounds are often important determinants of male Mating success but have been little studied in social insects. This is because Mating in social insects is often difficult to manipulate experimentally, and first evidence for an explicit influence of accessory gland secretions on male Mating success in social insects was obtained only recently. Here we perform a comparative analysis of male sexual organs across 11 species of attine fungus-growing ants, representing both genera with single- and multiple-queen Mating. We found that the general morphology of the male sexual organs was very similar across all species, but the relative sizes of the accessory glands and the sperm-containing accessory testes vary significantly across species. Small testes and large accessory glands characterize species with singly mated queens, whereas the opposite is found in species with multiply mated queens. However, in the social parasite Acromyrmex insinuator, in which queens have secondarily reverted to single Mating, males have accessory gland characteristics reminiscent of the lower attine ants, but without having significantly reduced their investment in sperm production. We hypothesize that the main function of accessory gland compounds in attine ants is to monopolize male paternity in similar ways as known from other social insects. This would imply that the evolution of polyandry in the terminal clade of the fungus-growing ants (the leafcutter ants) has resulted in selection for decreased investment by males in accessory gland secretions and increased investment in sperm number, in response to sperm competition for sperm storage. Copyright 2004.
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queen Mating Frequency and relatedness in young atta sexdens colonies
Insectes Sociaux, 2000Co-Authors: Else J Fjerdingstad, Jacobus J BoomsmaAbstract:Queen Mating Frequency is correlated with mature colony size across monogynous ant species as a whole. However, recent comparisons between Atta and Acromyrmex leafcutter ants found an opposite trend. We tested whether this result could be reproduced for Atta sexdens, using a new Atta colombica microsatellite marker to analyse queens and worker offspring from six young colonies. We found that all queens had mated multiply and used sperm from at least 2-3 males. This result is comparable to previous findings for Atta colombica and seems to confirm that queen Mating Frequency in Atta is lower than in Acromyrmex.
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multiple Mating and facultative polygyny in the panamanian leafcutter ant acromyrmex echinatior
Behavioral Ecology and Sociobiology, 1999Co-Authors: Dorte Bekkevold, Jane Frydenberg, Jacobus J BoomsmaAbstract:Queen Mating Frequency of the facultatively polygynous ant Acromyrmex echinatior was investigated by analysing genetic variation at an (AG)n repeat microsatellite locus in workers and sexuals of 20 colonies from a single Panamanian population. Thirteen colonies were found to be monogynous, 5 colonies contained multiple queens, whereas the queen number of 2 colonies remained unresolved. Microsatellite genotypes indicated that 12 out of 13 queens were inseminated by multiple males (polyandry). The mean queen Mating Frequency was 2.53 and the mean genetically effective paternity Frequency was 2.23. These values range among the highest found in ants, and the results are in keeping with the high Mating frequencies reported for other species of leafcutter ants. Consistent skew in the proportional representation of different patrilines within colonies was found, and this remained constant in two consecutive samples of offspring. Dissections showed that all examined queens from multiple-queen colonies were mated egg-layers. The mean relatedness value among nestmate workers in polygynous colonies was lower than that for monogynous colonies. No diploid males were detected in a sample of 70 genotyped males. Worker production of males was detected in one queenless colony. We discuss our findings in relation to known patterns of multiple maternity and paternity in other eusocial Hymenoptera.
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positive association of queen number and queen Mating Frequency myrmica ants a challenge to the genetic variability hypotheses
Behavioral Ecology and Sociobiology, 1999Co-Authors: Jes S Pedersen, Jacobus J BoomsmaAbstract:Detailed knowledge of the Mating system in specific social insect populations is essential for testing general evolutionary hypotheses of multiple paternity in eusocial Hymenoptera. We have studied the Mating Frequency of queens in a polygynous population of the red ant Myrmica sulcinodis. Genetic mother-offspring analysis showed that double Mating occurred at a considerable Frequency, but that the effective number of queen-mates remained close to one. After quantifying the effects of multiple maternity (polygyny) and multiple paternity (polyandry) on the genetic diversity of workers, we conclude that multiple paternity in M. sulcinodis did not evolve as an adaptation to increase genetic variation within colonies. Contrary to the predictions from `genetic variability' hypotheses, we found a positive correlation between colony-specific queen number and the average number of mates per queen. Such positive association of queen number and Frequency of multiple Mating was also found after analysing comparative data across six species of Myrmica ants. These results suggest that resticted dispersal of young queens may be a common factor promoting both polygyny and polyandry at the same time, and that moderate degrees of multiple Mating may be an unselected consequence of (1) Mating at low cost when Mating occurs close to the nest and (2) Mating in swarms with a highly male biased operational sex ratio. Future comparative tests of genetic-variability hypotheses should therefore not include species with such evolutionary derived Mating system characteristics.
Kim Fowler - One of the best experts on this subject based on the ideXlab platform.
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Direct and correlated responses to artificial selection on male Mating Frequency in the stalk-eyed fly Cyrtodiopsis dalmanni
J EVOLUTION BIOL, 2005Co-Authors: Kim FowlerAbstract:Traditionally it was thought that fitness-related traits such as male Mating Frequency, with a history of strong directional selection, should have little additive genetic variance and thus respond asymmetrically to bidirectional artificial selection. However, recent findings and theory suggest that a balance between selection for increased male Mating Frequency and opposing selection pressures on physiologically linked traits will cause male Mating Frequency to have high additive genetic variation and hence respond symmetrically to selection. We tested these hypotheses in the stalk-eyed fly, Cyrtodiopsis dalmanni, in which males hold harems comprising many females and so have the opportunity to mate at extremely high frequencies. We subjected male stalk-eyed flies to artificial selection for increased ('high') and decreased ('low') Mating Frequency in the presence of ecologically realistic, high numbers of females. High line males mated significantly more often than control or low line males. The direct response to selection was approximately symmetric in the high and low lines, revealing high additive genetic variation for, and no significant genetic constraints on, increased male Mating Frequency in C. dalmanni. In order to investigate trade-offs that might constrain male Mating Frequency under natural conditions we examined correlated responses to artificial selection. We measured accessory gland length, testis length and eyespan after 7 and 14 generations of selection. High line males had significantly larger accessory glands than low line males. No consistent correlated responses to selection were found in testis length or eyespan. Our results suggest that costs associated with the production and maintenance of large accessory glands, although yet to be identified, are likely to be a major constraint on Mating Frequency in natural populations of C. dalmanni.
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No detectable genetic correlation between male and female Mating Frequency in the stalk-eyed fly Cyrtodiopsis dalmanni
HEREDITY, 2005Co-Authors: Kim FowlerAbstract:There is much interest in explaining why female insects mate multiply. Females of the stalk- eyed fly Cyrtodiopsis dalmanni can mate several times each day in a lifetime which may span several months. There are many adaptive explanations, but one hypothesis that has received little rigorous empirical attention is that female multiple Mating has evolved for non-adaptive reasons as a correlated response to selection for high male Mating Frequency rather than because of direct or indirect benefits accruing to females. We tested this hypothesis in stalk- eyed flies by measuring the Mating Frequency of females from lines that exhibited a direct response in males to artificial selection for increased ('high') and decreased ('low') male Mating Frequency. We found that the Mating Frequency of high- line females did not differ from that of low- line females. Hence, there was no support for a genetic correlation between male and female Mating Frequency in this species. Our study suggests that the genes which influence reMating may not be the same in the sexes, and that females remate frequently in this species to gain as yet unidentified benefits.
Laurianne Leniaud - One of the best experts on this subject based on the ideXlab platform.
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evolution of reproductive traits in cataglyphis desert ants Mating Frequency queen number and thelytoky
Behavioral Ecology and Sociobiology, 2016Co-Authors: Serge Aron, Patrick Mardulyn, Laurianne LeniaudAbstract:Abstract: Cataglyphis desert ants display unique variation in their breeding systems, making this genus a particularly interesting model to study the evolution of derived reproductive traits in eusocial Hymenoptera. Colonies may be headed by a single or several queens, and queens may be singly or multiply mated. Furthermore, in a number of species, both the workers and queens do reproduce asexually by thelytokous parthenogenesis. We examined whether the variability in reproductive traits is the result of a single evolutionary transition or of multiple independent evolutionary transitions, per trait. First, we inferred a phylogenetic estimate for the genus by analyzing DNA sequence variation among several species at four independent loci. Our phylogenetic hypothesis confirms the monophyly of previously defined species groups. Second, we examined the evolution of four reproductive traits in the genus (queen Mating Frequency, colony queen number, as well as worker reproduction and queen reproduction by thelytokous parthenogenesis), by inferring the state of these traits at the ancestral nodes. Our results show that polyandry and monogyny are the most likely conditions for the ancestor of the genus; the status of worker and queen thelytoky remains ambiguous. Genetic diversity within colonies may have been a major driver for the evolution of derived reproductive traits in Cataglyphis. Significance statement: Kinship among group members has long been recognized as a main factor promoting the evolution of sociality and reproductive altruism. In eusocial Hymenoptera (ants, bees, wasps), at least three reproductive characteristics were shown to profoundly affect colony kin structure and may have played a key role in the evolution and maintenance of reproductive altruism: the queen Mating Frequency, the number of reproductive queens in a colony, and reproduction by parthenogenesis. We infer the evolution of these three reproductive traits in Cataglyphis desert ants, a genus displaying considerable variation in reproductive strategies. We propose a phylogenetic estimate for the genus, from variation at four loci. Then, we show that multiple evolutionary changes occurred for all three reproductive characters studied. Our results suggest that selection for enhanced colony genetic diversity has driven the evolution of reproductive traits away from their ancestral state.
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evolution of reproductive traits in cataglyphis desert ants Mating Frequency queen number and thelytoky
Behavioral Ecology and Sociobiology, 2016Co-Authors: Serge Aron, Patrick Mardulyn, Laurianne LeniaudAbstract:Cataglyphis desert ants display unique variation in their breeding systems, making this genus a particularly interesting model to study the evolution of derived reproductive traits in eusocial Hymenoptera. Colonies may be headed by a single or several queens, and queens may be singly or multiply mated. Furthermore, in a number of species, both the workers and queens do reproduce asexually by thelytokous parthenogenesis. We examined whether the variability in reproductive traits is the result of a single evolutionary transition or of multiple independent evolutionary transitions, per trait. First, we inferred a phylogenetic estimate for the genus by analyzing DNA sequence variation among several species at four independent loci. Our phylogenetic hypothesis confirms the monophyly of previously defined species groups. Second, we examined the evolution of four reproductive traits in the genus (queen Mating Frequency, colony queen number, as well as worker reproduction and queen reproduction by thelytokous parthenogenesis), by inferring the state of these traits at the ancestral nodes. Our results show that polyandry and monogyny are the most likely conditions for the ancestor of the genus; the status of worker and queen thelytoky remains ambiguous. Genetic diversity within colonies may have been a major driver for the evolution of derived reproductive traits in Cataglyphis. Kinship among group members has long been recognized as a main factor promoting the evolution of sociality and reproductive altruism. In eusocial Hymenoptera (ants, bees, wasps), at least three reproductive characteristics were shown to profoundly affect colony kin structure and may have played a key role in the evolution and maintenance of reproductive altruism: the queen Mating Frequency, the number of reproductive queens in a colony, and reproduction by parthenogenesis. We infer the evolution of these three reproductive traits in Cataglyphis desert ants, a genus displaying considerable variation in reproductive strategies. We propose a phylogenetic estimate for the genus, from variation at four loci. Then, we show that multiple evolutionary changes occurred for all three reproductive characters studied. Our results suggest that selection for enhanced colony genetic diversity has driven the evolution of reproductive traits away from their ancestral state.
Kevin Fowler - One of the best experts on this subject based on the ideXlab platform.
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adaptive maintenance of fertility in the face of meiotic drive
bioRxiv, 2019Co-Authors: Lara Meade, Sam Ronan Finnegan, Ridhima Kad, Kevin Fowler, Andrew PomiankowskiAbstract:Abstract Selfish genetic elements that gain a transmission advantage through the destruction of sperm have grave implications for drive male fertility. We report the first evidence for a male adaptation to this negative consequence of unsuppressed drive. In the X-linked SR meiotic drive system of a stalk-eyed fly, we found that drive males had greatly enlarged testes and so maintained high fertility despite the destruction of half their sperm. This was the case even when males were challenged with fertilising five females. Conversely, we observed an overt trade-off with Mating Frequency due to reduced allocation of resources to accessory glands. Body size and eyespan were also reduced, which are likely to impair viability, pre-copulatory competition and Mating Frequency. Gaining an understanding of the extent to which drivers promote the evolution of adaptive responses in the host is essential for predictions of equilibrium frequencies in wild populations.
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Mating induced reduction in accessory reproductive organ size in the stalk eyed fly cyrtodiopsis dalmanni
BMC Evolutionary Biology, 2005Co-Authors: David W Rogers, Tracey Chapman, Kevin Fowler, Andrew PomiankowskiAbstract:Internal reproductive organ size is an important determinant of male reproductive success. While the response of testis length to variation in the intensity of sperm competition is well documented across many taxa, few studies address the importance of testis size in determining other components of male reproductive success (such as Mating Frequency) or the significance of size variation in accessory reproductive organs. Accessory gland length, but not testis length, is both phenotypically and genetically correlated with male Mating Frequency in the stalk-eyed fly Cyrtodiopsis dalmanni. Here we directly manipulate male Mating status to investigate the effect of copulation on the size of both the testes and the accessory glands of C. dalmanni. Accessory gland length was positively correlated with male Mating Frequency. Copulation induced a significant decrease in accessory gland size. The size of the accessory glands then recovered slowly over the next 8–48 hours. Neither testis length nor testis area was altered by copulation. These results reveal that the time course of accessory gland recovery corresponds to field observations of Mating behaviour and suggest that accessory gland size may limit male Mating Frequency in C. dalmanni.
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accessory gland size influences time to sexual maturity and Mating Frequency in the stalk eyed fly cyrtodiopsis dalmanni
Behavioral Ecology, 2003Co-Authors: Richard Baker, Kevin Fowler, Andrew Pomiankowski, Matthew Denniff, Peter Futerman, Tracey ChapmanAbstract:Age at first reproduction is an extremely important life-history trait. Several factors such as nutritional state and age-specific fecundity have been shown to influence time to sexual maturity; however, little work has been done in insects. We addressed this in a stalk-eyed fly (Cyrtodiopsis dalmanni), by testing the hypothesis that time to sexual maturity is associated with the development of male internal reproductive structures. We found that sexual maturity was attained after an increased rate of growth in the accessory glands, several days after mature sperm bundles, and motile sperm were observed in the testes. Although testis development is essential, the results suggest that accessory gland growth is more closely associated with the time taken to reach sexual maturity than is testis growth. When we manipulated the growth of testes and accessory glands via a dietary manipulation, we found that delayed growth rates increased the time taken to reach sexual maturity. Among the delayed individuals, sexually mature males had larger accessory glands, but not testes, than did immature males. In adult males, Mating Frequency was significantly positively correlated with accessory gland size, but not with testis length or body size. We conclude that accessory gland size is a critical determinant of sexual maturity and male Mating Frequency in this species.
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selection on age at reproduction in drosophila melanogaster female Mating Frequency as a correlated response
Evolution, 2000Co-Authors: Carla M Sgro, Kevin Fowler, Giselle Geddes, Linda PartridgeAbstract:We examined the effect of selection for age at reproduction on female Mating Frequency and fertility in female Drosophila melanogaster. Selection for increased age at reproduction (and hence increased lifespan) resulted in higher late life female Mating frequencies, while females selected for younger ages at reproduction showed increased early life Mating frequencies. These results indicate that the response to selection on age at reproduction has involved changes in the scheduling of female reproductive behavior.