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Laurent Keller - One of the best experts on this subject based on the ideXlab platform.
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Polymorphic social organization in an ant
Proceedings of The Royal Society B: Biological Sciences, 2009Co-Authors: Richard J. Gill, Andres N. Arce, Laurent Keller, Robert L. HammondAbstract:Identifying species exhibiting variation in social organization is an important step towards explaining the genetic and environmental factors underlying social evolution. In most studied populations of the ant Leptothorax acervorum, reproduction is shared among queens in multiple queen colonies (polygyny). By contrast, reports from other populations, but based on weaker evidence, suggest a single queen may monopolize all reproduction in multiple queen colonies (functional Monogyny). Here we identify a marked polymorphism in social organization in this species, by conclusively showing that functional Monogyny is exhibited in a Spanish population, showing that the social organization is stable and not purely a consequence of daughter queens overwintering, that daughter queen re-adoption is frequent and queen turnover is low. Importantly, we show that polygynous and functionally monogynous populations are not genetically distinct from one another based on mtDNA and nDNA. This suggests a recent evolutionary divergence between social phenotypes. Finally, when functionally monogynous and polygynous colonies were kept under identical laboratory conditions, social organization did not change, suggesting a genetic basis for the polymorphism. We discuss the implications of these findings to the study of reproductive skew.
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COLONY SEX RATIOS IN THE FACULTATIVELY POLYGYNOUS ANT PHEIDOLE PALLIDULA: A REANALYSIS WITH NEW DATA
Evolution; international journal of organic evolution, 2004Co-Authors: Ken R. Helms, Luc Passera, Denis Fournier, Laurent Keller, Serge AronAbstract:A recent study by Fournier et al. (2003) provides important new information on sex allocation in the ant Pheidole pallidula, and proposes a new scenario for sex-ratio evolution in P. pallidula and similar species. However, Helms proposed to the authors that two important conclusions of the study were questionable because of potential problems with the analyses. Here we provide new data and a reanalysis that strengthens the conclusion that colony sex ratio is associated with breeding system (i.e., polygyny or Monogyny). However, the proposal that colonies shift from Monogyny to polygyny when they become larger and more productive is weakened because there is substantial overlap in productivity between monogynous and polygynous colonies.
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experimental conversion of colony social organization by manipulation of worker genotype composition in fire ants solenopsis invicta
Behavioral Ecology and Sociobiology, 2002Co-Authors: Kenneth G. Ross, Laurent KellerAbstract:Previous studies have shown that colony social organization in Solenopsis invicta is under strong genetic control. Colonies containing some proportion of workers with the Bb or bb genotypes at the gene Gp-9 display polygyne social organization (multiple reproductive queens per colony), whereas colonies with only BB workers express monogyne organization (single reproductive queen per colony). The hypothesis that the presence of workers bearing the b allele confers the polygyne social phenotype on a colony leads to the prediction that social organization can be manipulated by experimentally altering frequencies of adult workers bearing this allele. We did this by replacing queens in colonies of each social form with single queens of the alternate form, which differ in Gp-9 genotype. As worker Gp-9 genotype compositions changed, experimental colonies switched to the alternate social organization. These switches occurred when frequencies of workers with the b allele passed an identifiable threshold, such that colonies with fewer than 5% such workers behaved like monogyne colonies and those with more than 10% behaved like polygyne colonies. Our data thus confirm the prediction that colony social organization in this ant can be altered by manipulating adult worker genotype compositions, and thereby support the hypothesis that the expression of polygyny requires the presence of adult workers bearing the b allele at Gp-9.
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Queen number and sociality in insects
1993Co-Authors: Laurent KellerAbstract:List of contributors 1. Opportunities and pitfalls in co-operative reproduction 2. Reproductive structure and reproductive roles in colonies of eusocial insects 3. Queen - queen conflicts in polygynous societies: mutual tolerance and reproductive skew 4. Sex ratio variation in polygynous ants 5. The effects of polygny and colony life history on optimal sex investment 6. Genetic relatedness and its components in polygynous colonies of social insects 7. The maintenance of high genetic relatedness in multi-queen colonies of social wasps 8. The evolutiuon of polygyny in primitively eusocial polistine wasps with special rerference to the genus Ropalidia 9. Serial polygyny in the primitively eusocial wasp Ropalidia marginata: implications for the evolution of sociality 10. Multiple - foundress associations in sweat bees 11. Monogyny and polygyny in ponerine ants with or without queens 12. Ecological determinants of queen number in ants 13. Distribution and ecology of queen number in ants of the genus Myrmica 14. Monogyny and polygyny in Formica ants: the result of alternative dispersal tactics 15. Queen - queen interactions in polygynous ants 16. Kin discrimination and division of labour among matrilines in the polygynous carpenter ant, Camponotus planatus 17. Selective pressures on pleometrosis and secondary polygyny: a comparison of termites and ants Glossary Author index Subject index
Jürgen Heinze - One of the best experts on this subject based on the ideXlab platform.
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Electronic supplementary material - queen, figure 2 from Life-history evolution in ants: the case of Cardiocondyla
2017Co-Authors: Jürgen HeinzeAbstract:Phylogeny of the ant genus Cardiocondyla and reconstruction of the most parsimonious ancestral queen number of the genus (polygyny: black; Monogyny: blue; functional Monogyny / queen competition: green; unknown: hatched grey). For details see caption of figure 1
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First come, first served: the first-emerging queen monopolizes reproduction in the ant Cardiocondyla “argyrotricha”
Journal of Ethology, 2017Co-Authors: Christine V. Schmidt, Andreas Heimbucher, Abel Bernadou, Jürgen HeinzeAbstract:While colonies of most tropical species of the ant genus Cardiocondyla regularly contain multiple egg-laying queens (polygyny), single-queening (Monogyny) evolved convergently in a Palearctic clade of Cardiocondyla and in Southeast Asian C. “ argyrotricha .” In the latter species, Monogyny is probably an adaptation to patchily distributed but highly stable nest sites. In experimentally orphaned colonies of C. “ argyrotricha ,” the first emerging queen shed its wings, began to lay eggs, and stayed mostly on the brood pile. Queens that emerged later remained in the peripheral areas of the nest without dispersing but retained their wings even after mating in the nest. Aggressive interactions among queens and between workers and queens were occasionally observed, but it appears that the order of queen emergence determines which of them will become reproductive and inherit the nest. We conclude that young queens commonly compete for nest inheritance in some species of Cardiocondyla and that queen–queen antagonism does not necessarily involve lethal fighting.
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Phylogeography of social polymorphism in a boreo-montane ant
BMC evolutionary biology, 2016Co-Authors: Jürgen Trettin, Shobhit Agrawal, Jürgen HeinzeAbstract:Background The disjunct distribution of several Palearctic species has been widely shaped by the changes in climatic conditions during the Quaternary. The observed genetic differentiation or reproductive isolation between extant populations may be the outcome of their contemporary geographic separation or reproductive incompatibility due to differences in phenotypic traits which have evolved in isolated refugia. In the boreal ant Leptothorax acervorum, colonies from central and peripheral populations differ in social structure: colonies from Central and Northern Europe may contain several equally reproductive queens (facultative polygyny), while in colonies from peripheral populations in Spain only one the most dominant of several queens lays eggs (functional Monogyny). By reconstructing the specie’s evolutionary and demographic history in Southwestern Europe we examine whether variation in social organization is associated with restricted gene flow between the two social forms.
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Polygyny, Inbreeding, and Wingless Males in the Malagasy Ant Cardiocondyla shuckardi Forel (Hymenoptera, Formicidae)
Sociobiology, 2014Co-Authors: Jürgen Heinze, Alexandra Schrempf, Honoré Rakotondrazafy, Tsiriniaina Rakotondranaivo, Brian L. FisherAbstract:The ant genus Cardiocondyla exhibits a fascinating diversity of its reproductive biology, with winged and wingless males, long-winged and short-winged queens, strict Monogyny and facultative polygyny with or without queen fighting. Here we report on the previously unstudied Malagasy ant C. shuckardi . We describe the nesting habits, male morphology and colony structure of this species. Furthermore, based on the genotypes from three microsatellite loci we document a very high incidence of sib-mating.
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Reproductive Competition in Colonies of the Ant Leptothorax gredleri
Ethology, 2010Co-Authors: Jürgen Heinze, Norbert Lipski, Bert HölldoblerAbstract:Colonies of the ant, Leptothorax (s. str.) gredleri may contain several inseminated female reproductives of which typically only one is laying eggs. Observations suggest that “functional Monogyny” is caused by aggressive interactions among nestmate queens. Only the most dominant queen reproduces. Subordinate queens either leave the colony to found their own nests solitarily or by budding, or stay in the nest without reproducing, but may eventually replace the dominant queen. The interrelations of life history of L. gredleri, population structure and habitat characteristics are examined.
Serge Aron - One of the best experts on this subject based on the ideXlab platform.
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social structure and genetic distance mediate nestmate recognition and aggressiveness in the facultative polygynous ant pheidole pallidula
PLOS ONE, 2016Co-Authors: Denis Fournier, Jean Christophe De Biseau, Sophie De Laet, Luc Passera, Alain Lenoir, Serge AronAbstract:In social insects, the evolutionary stability of cooperation depends on the privileged relationships between individuals of the social group, which is facilitated by the recognition of relatives. Nestmate recognition is based on genetically determined cues and/or environmentally derived chemical components present on the cuticle of individuals. Here, we studied nestmate recognition in the ant Pheidole pallidula, a species where both single-queen (monogyne) and multiple-queen (polygyne) colonies co-occur in the same population. We combined geographical, genetic and chemical analyses to disentangle the factors influencing the level of intraspecific aggressiveness. We show that encounters between workers from neighbouring colonies (i.e., nests less than 5 m away) are on average less aggressive than those between workers from more distant colonies. Aggressive behaviour is associated with the level of genetic difference: workers from monogyne colonies are more aggressive than workers from polygyne colonies, and the intensity of aggressiveness is positively associated with the genetic distance between colonies. Since the genetic distance is correlated with the spatial distance between pairs of colonies, the lower level of aggression toward neighbours may result from their higher relatedness. In contrast, the analysis of overall cuticular hydrocarbon profiles shows that aggressive behaviour is associated neither with the chemical diversity of colonies, nor with the chemical distances between them. When considering methyl-branched alkanes only, however, chemical distances differed between monogyne and polygyne colonies and were significantly associated with aggressiveness. Altogether, these results show that the social structure of colonies and the genetic distances between colonies are two major factors influencing the intensity of agonistic behaviours in the ant P. pallidula.
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COLONY SEX RATIOS IN THE FACULTATIVELY POLYGYNOUS ANT PHEIDOLE PALLIDULA: A REANALYSIS WITH NEW DATA
Evolution; international journal of organic evolution, 2004Co-Authors: Ken R. Helms, Luc Passera, Denis Fournier, Laurent Keller, Serge AronAbstract:A recent study by Fournier et al. (2003) provides important new information on sex allocation in the ant Pheidole pallidula, and proposes a new scenario for sex-ratio evolution in P. pallidula and similar species. However, Helms proposed to the authors that two important conclusions of the study were questionable because of potential problems with the analyses. Here we provide new data and a reanalysis that strengthens the conclusion that colony sex ratio is associated with breeding system (i.e., polygyny or Monogyny). However, the proposal that colonies shift from Monogyny to polygyny when they become larger and more productive is weakened because there is substantial overlap in productivity between monogynous and polygynous colonies.
Jutta M. Schneider - One of the best experts on this subject based on the ideXlab platform.
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Sexual Cannibalism as a Manifestation of Sexual Conflict
Cold Spring Harbor perspectives in biology, 2014Co-Authors: Jutta M. SchneiderAbstract:Sexual cannibalism is a well-known example for sexual conflict and has many facets that determine the costs and benefits for the cannibal and the victim. Here, I focus on species in which sexual cannibalism is a general component of a mating system in which males invest maximally in mating with a single (Monogyny) or two (bigyny) females. Sexual cannibalism can be a male strategy to maximize paternity and a female strategy to prevent paternity monopolization by any or a particular male. Considerable variation exists between species (1) in the potential of males to monopolize females, and (2) in the success of females in preventing monopolization by males. This opens up exciting future possibilities to investigate sexually antagonistic coevolution in a largely unstudied mating system.
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A mate to die for? A model of conditional Monogyny in cannibalistic spiders
Ecology and evolution, 2012Co-Authors: Lutz Fromhage, Jutta M. SchneiderAbstract:Monogynous males in various species actively limit themselves to mating with a single female in their lifetime. Whereas previous models have considered Monogyny as an obligate mating strategy, here we explore the potential of Monogyny to evolve as a context-specific (conditional) behavior. Using a state-dependent dynamic game model based on the biology of the cannibalistic spider Argiope bruennichi, we confirm that conditional Monogyny can evolve under broad conditions, including an even sex ratio. We predict that males should make a terminal investment when mating with large, virgin females, especially if population density is low and the encounter occurs late in the season. We encourage empirical tests for the existence of conditional Monogyny in all species where Monogyny occurs in the absence of strict morphological constraints that would make it obligatory.
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Conditional Monogyny: female quality predicts male faithfulness.
Frontiers in zoology, 2012Co-Authors: Klaas W. Welke, Stefanie M. Zimmer, Jutta M. SchneiderAbstract:Introduction: Male Monogyny in the absence of paternal investment is arguably one of the most puzzling mating systems. Recent evidence suggests that males of monogynous species adjust their life-history and their mating decision to shifting spatial and temporal selection regimes. In the cannibalistic wasp spider Argiope bruennichi males can be either monogynous or mate with a maximum of two females. We studied factors underlying male mating decisions in a natural population over a whole mating season. We documented all matings and categorized the males into single-mated and double-mated monogynous as well as bigynous males. Results: We found that all categories were continuously present with relatively stable frequencies despite changes in the operational sex ratio. Males were more likely monogynous when copulating with relatively heavy and old females and otherwise bigynous. Conclusion: Our results imply that males make conditional mating decisions based on the quality of the first female they encounter but do not adjust their mating tactic to the local selection regime.
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Funding Information
2012Co-Authors: Lutz Fromhage, Jutta M. Schneider, Deutsche ForschungsgemeinschaftAbstract:mate to die for? A model of conditional Monogyny i
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Monogynous mating strategies in spiders
Animal Behaviour: Evolution and Mechanisms, 2010Co-Authors: Jutta M. Schneider, Lutz FromhageAbstract:To understand the evolution of mating systems, we need to consider why reproductive strategies differ between species in the way they do. For example, males in most mammals appear entirely specialised on mating with many females, whereas males in many birds also invest in offspring quality by providing paternal care. Alternatively or additionally, males may invest in enhancing their paternity share in any mating they get. Taken to the extreme, this may result in males investing maximally in gaining paternity with one or two females only, in the absence of paternal care. Mating systems with monogynous (or bigynous) males and polyandrous females are taxonomically widespread but relatively rare overall. In spiders, however, low male mating frequencies have evolved several times independently and are associated with remarkable adaptations that include sexual cannibalism and genital damage. In the first part of this chapter, we describe the mating strategies, and the associated costs and benefits of sexual cannibalism and genital damage, of selected spider species that represent independent evolutionary origins of these traits. We then introduce models that investigate the evolution of mating systems with low male mating frequencies. The models predict that a male-biased sex ratio is required for Monogyny to evolve. We outline how such a sex ratio bias may have arisen in concert with female-biased sexual size dimorphism. Finally, we discuss Monogyny in the light of sexual conflict theory.
Kenneth G. Ross - One of the best experts on this subject based on the ideXlab platform.
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Experimental Conversion of Colony Social Organization in Fire Ants (Solenopsis invicta): Worker Genotype Manipulation in the Absence of Queen Effects
Journal of Insect Behavior, 2008Co-Authors: Dietrich Gotzek, Kenneth G. RossAbstract:Colony social organization in the fire ant Solenopsis invicta appears to be under strong genetic control. In the invasive USA range, polygyny (multiple queens per colony) is marked by the presence of the Gp-9 ^ b allele in most of a colony’s workers, whereas Monogyny (single queen per colony) is associated with the exclusive occurrence of the Gp-9 ^ B allele. Ross and Keller, Behav Ecol Sociobiol 51:287–295 ( 2002 ) experimentally manipulated social organization by cross-fostering queens into colonies of the alternate form, thereby changing adult worker Gp-9 genotype frequencies over time. Although these authors showed that social behavior switched predictably when the frequency of b -bearing adult workers crossed a threshold of 5–10%, the possibility that queen effects caused the conversions could not be excluded entirely. We addressed this problem by fostering polygyne brood into queenright monogyne colonies. All such treatment colonies switched social organization to become polygyne, coincident with their proportions of b -bearing workers exceeding 12%. Our results support the conclusion that polygyny in S. invicta is induced by a minimum frequency of colony workers carrying the b allele, and further confirm that its expression is independent of queen genotype or history, worker genotypes at genes not linked to Gp-9 , and colony genetic diversity.
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Alternative genetic foundations for a key social polymorphism in fire ants.
Genetics, 2003Co-Authors: Kenneth G. Ross, Michael J. B. Krieger, Dewayne ShoemakerAbstract:Little is known about the genetic foundations of colony social organization. One rare example in which a single major gene is implicated in the expression of alternative social organizations involves the presumed odorant-binding protein gene Gp-9 in fire ants. Specific amino acid substitutions in this gene invariably are associated with the expression of Monogyny (single queen per colony) or polygyny (multiple queens per colony) in fire ant species of the Solenopsis richteri clade. These substitutions are hypothesized to alter the abilities of workers to recognize queens and thereby regulate their numbers in a colony. We examined whether these same substitutions underlie the Monogyny/polygyny social polymorphism in the distantly related fire ant S. geminata. We found that Gp-9 coding region sequences are identical in the polygyne and monogyne forms of this species, disproving our hypothesis that one or a few specific amino acid replacements in the protein are necessary to induce transitions in social organization in fire ants. On the other hand, polygyne S. geminata differs genetically from the monogyne form in ways not mirrored in the two forms of S. invicta, a well-studied member of the S. richteri clade, supporting the conclusion that polygyny did not evolve via analogous routes in the two lineages. Specifically, polygyne S. geminata has lower genetic diversity and different gene frequencies than the monogyne form, suggesting that the polygyne form originated via a founder event from a local monogyne population. These comparative data suggest an alternative route to polygyny in S. geminata in which loss of allelic variation at genes encoding recognition cues has led to a breakdown in discrimination abilities and the consequent acceptance of multiple queens in colonies.
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experimental conversion of colony social organization by manipulation of worker genotype composition in fire ants solenopsis invicta
Behavioral Ecology and Sociobiology, 2002Co-Authors: Kenneth G. Ross, Laurent KellerAbstract:Previous studies have shown that colony social organization in Solenopsis invicta is under strong genetic control. Colonies containing some proportion of workers with the Bb or bb genotypes at the gene Gp-9 display polygyne social organization (multiple reproductive queens per colony), whereas colonies with only BB workers express monogyne organization (single reproductive queen per colony). The hypothesis that the presence of workers bearing the b allele confers the polygyne social phenotype on a colony leads to the prediction that social organization can be manipulated by experimentally altering frequencies of adult workers bearing this allele. We did this by replacing queens in colonies of each social form with single queens of the alternate form, which differ in Gp-9 genotype. As worker Gp-9 genotype compositions changed, experimental colonies switched to the alternate social organization. These switches occurred when frequencies of workers with the b allele passed an identifiable threshold, such that colonies with fewer than 5% such workers behaved like monogyne colonies and those with more than 10% behaved like polygyne colonies. Our data thus confirm the prediction that colony social organization in this ant can be altered by manipulating adult worker genotype compositions, and thereby support the hypothesis that the expression of polygyny requires the presence of adult workers bearing the b allele at Gp-9.