scholarly journals The value of oviposition timing, queen presence and kinship in a social insect

2013 ◽  
Vol 280 (1766) ◽  
pp. 20131231 ◽  
Author(s):  
Martina Ozan ◽  
Heikki Helanterä ◽  
Liselotte Sundström

Reproductive cooperation confers benefits, but simultaneously creates conflicts among cooperators. Queens in multi-queen colonies of ants share a nest and its resources, but reproductive competition among queens often results in unequal reproduction. Two mutually non-exclusive factors may produce such inequality in reproduction: worker intervention or queen traits. Workers may intervene by favouring some queens over others, owing to either kinship or queen signals. Queens may differ in their intrinsic fecundity at the onset of oviposition or in their timing of the onset of oviposition, leading to their unequal representation in the brood. Here, we test the role of queen kin value (relatedness) to workers, timing of the onset of oviposition and signals of presence by queens in determining the maternity of offspring. We show that queens of the ant Formica fusca gained a significantly higher proportion of sexuals in the brood when ovipositing early, and that the presence of a caged queen resulted in a significant increase in both her share of sexual brood and her overall reproductive share. Moreover, the lower the kin value of the queen, the more the workers invested in their own reproduction by producing males. Our results show that both kinship and breeding phenology influence the outcome of reproductive conflicts, and the balance of direct and indirect fitness benefits in the multi-queen colonies of F. fusca .

2014 ◽  
Vol 60 (1) ◽  
pp. 131-136 ◽  
Author(s):  
Heikki Helanterä ◽  
Stephen J. Martin ◽  
Francis L.W. Ratnieks

Abstract Inclusive fitness benefits depend on recognizing the right individuals to interact with. Social insect nests protect themselves from non-kin intruders through nestmate recognition based on chemical cues. The recognition cues on adult individuals are from a mixture of genetic and environmental sources, but the ontogeny and use of recognition cues on eggs has not been previously assessed. We studied recognition by workers of eggs that were either nestmates or non-nestmates. and the ontogeny of recognition cues on eggs in the ant Formica fusca, a species with precise egg recognition abilities. Workers were able to discriminate among freshly laid eggs with no nest derived cues on them, and the egg surface chemicals varied among nests in these eggs, suggesting that queen derived cues are used in nestmate recognition. The results are discussed in the light of their implications on deceptive social parasite strategies and within colony conflicts.


2013 ◽  
Vol 9 (1) ◽  
pp. 20120569 ◽  
Author(s):  
R. Fredrik Inglis ◽  
Alex R. Hall ◽  
Angus Buckling

The ubiquitous production of antibacterial toxins, such as bacteriocins, is an ecologically significant class of interbacterial interactions that have primarily evolved through their indirect fitness benefits to the producer. Bacteria release bacteriocins into the environment at a cost to individual cell, but individual bacteriocin-producing cells are unlikely to gain any direct benefit from their own toxin; indeed, cell lysis is required in many species. There is a growing body of research describing the ecological conditions that can favour the evolution of bacteriocin production. However, an important aspect of many bacteriocins has yet to be investigated: the ability of bacteriocin-producing cells to neutralize toxin (‘soaking’) produced by other clonemates. By competing Pseudomonas aeruginosa bacteriocin-producing wild-type and ‘non-soaking’ strains against a bacteriocin-susceptible strain, we find that soaking markedly reduces the fitness of a bacteriocin-producing strain at both high and low frequencies.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Elisabetta Palagi ◽  
Marta Bertini ◽  
Giulia Annicchiarico ◽  
Giada Cordoni

Abstract Rapid Facial Mimicry (RFM), one of the possible predictors of emotional contagion, is defined as the rapid, involuntary and automatic replication of a facial expression. Up to now, RFM has been demonstrated in nonhuman animals exclusively during play. Since in bonobos, as in humans, socio-sexuality is a powerful tool for assessing/strengthening inter-individual relationships, we investigated RFM in this domain. Bonobos displayed silent bared-teeth (sbt, the most common facial expression during sexual contacts) more frequently after the detection of an sbt emitted by the trigger than in the no-detection condition. This is the first demonstration of the presence of RFM during sex. The occurrence of RFM was positively affected by the sex of the partners with female homo-sexual contacts being punctuated by a higher presence of RFM. At an immediate level, RFM increased the duration of homo- and hetero-sexual contacts. This finding suggests that RFM can increase individuals’ potential fitness benefits. By prolonging their sexual contacts, females can strengthen their social relationships thus increasing the probability to obtain priority over resources (RFM indirect fitness benefits). Via longer copulations, males can increase the probability to make females pregnant (RFM direct fitness benefits). In conclusion, in bonobos the access to the partner’s face during sexual contacts (face-to-face, proximate factor) and the role of socio-sexuality in increasing the individual direct and indirect fitness (ultimate factor) could have favoured the evolution of specific sexual facial expressions and their rapid mirror replication. Our findings on bonobos expand the role of RFM well beyond the animal play domain thus opening new scenarios for future comparative studies exploring the evolution of socio-sexuality in humans.


2019 ◽  
Vol 66 (4) ◽  
pp. 519-531 ◽  
Author(s):  
C. Morandin ◽  
A. Hietala ◽  
H. Helanterä

Abstract Social insect colonies are characterized by division of labour, and extensive morphological, physiological and behavioural differences between queens and workers. The storage protein vitellogenin (Vg) affects multiple aspects of social insect life histories, and has been suggested as a key player for caste differentiation and maintenance. Recently, three genes homologous to Vg have been described in the ant Formica exsecta. Their role is currently unclear but their structural variation suggests variable functions. We examined the expression patterns of the conventional Vg and the three Vg-like genes using qRT-PCR in the common black ant Formica fusca between queens and workers, between nurse and foragers workers, and across social contexts (queenless vs. queenright nests), and sampling time. As expected, we found a significant queen caste and nurse task-related increase for the conventional Vg, while Vg-like-C displayed a consistent forager-biased expression pattern. Task (forager vs. nurse) was the only factor that explained expression variation among workers in any of the studied genes. The removal of the queen did not affect expression, although the proportion of fertile nurses increased in queenless nests. The observed expression biases suggest that in Formica fusca, the ancestral duplication has led to alternative social functions for Vg-like genes across castes and tasks. To get a broader picture of the role of gene duplications in social evolution and the roles of Vg-like genes in caste differentiation and maintenance, how these genes achieve these roles at a molecular level need to be investigated further.


Author(s):  
Carsten Schradin ◽  
Rainer H. Straub

“Nothing in Biology makes sense, except in the light of evolution.” This famous citation of Theodosius Dobzhansky also underlies the integrative field of evolutionary medicine, which faces the challenge to combine (patho-)physiological mechanisms with evolutionary function. Here we introduce a concept from the study of animal behavior, which are the four questions of Tinbergen that consider: 1. the ontogeny of an individual describing its development, 2. its physiological machinery, which 3. has fitness consequences influencing 4. the evolutionary history (phylogeny) of future generations. It is shown how this concept can be applied to infectious disease and to chronic inflammatory systemic diseases. Evolutionary medicine takes lifetime reproductive success into account. The hypothesis to be tested is that mechanisms underlying a disease in old age might have higher fitness benefits in the pre-reproductive and/or reproductive life history stage, leading to an overall increased lifetime fitness.


2020 ◽  
Vol 31 (3) ◽  
pp. 731-738 ◽  
Author(s):  
Simon Vitt ◽  
Iris Madge Pimentel ◽  
Timo Thünken

Abstract While the importance of kin discrimination, that is, kin recognition and subsequent differential treatment of kin and nonkin, is well established for kin-directed cooperation or altruism, the role of kin discrimination in the context of kin competition and kin avoidance is largely unexplored. Theory predicts that individuals avoiding competition with kin should be favored by natural selection due to indirect fitness benefits. Using an experimental approach, we investigated whether the presence of same-sex kin affects avoidance and explorative behavior in subadult Pelvicachromis taeniatus, a West African cichlid fish with strong intrasexual competition in both sexes. Pelvicachromis taeniatus is capable of recognizing kin using phenotype matching and shows kin discrimination in diverse contexts. When exposed to a same-sex conspecific, both males and females tended to interact less with the related opponent. Moreover, individuals explored a novel environment faster after exposure to kin than to nonkin. This effect was more pronounced in females. Individuals avoiding the proximity of same-sex relatives may reduce kin competition over resources such as mating partners or food.


2017 ◽  
Vol 284 (1860) ◽  
pp. 20170441 ◽  
Author(s):  
Sally Le Page ◽  
Irem Sepil ◽  
Ewan Flintham ◽  
Tommaso Pizzari ◽  
Pau Carazo ◽  
...  

Males compete over mating and fertilization, and often harm females in the process. Inclusive fitness theory predicts that increasing relatedness within groups of males may relax competition and discourage male harm of females as males gain indirect benefits. Recent studies in Drosophila melanogaster are consistent with these predictions, and have found that within-group male relatedness increases female fitness, though others have found no effects. Importantly, these studies did not fully disentangle male genetic relatedness from larval familiarity, so the extent to which modulation of harm to females is explained by male familiarity remains unclear. Here we performed a fully factorial design, isolating the effects of male relatedness and larval familiarity on female harm. While we found no differences in male courtship or aggression, there was a significant interaction between male genetic relatedness and familiarity on female reproduction and survival. Relatedness among males increased female lifespan, reproductive lifespan and overall reproductive success, but only when males were familiar. By showing that both male relatedness and larval familiarity are required to modulate female harm, these findings reconcile previous studies, shedding light on the potential role of indirect fitness effects on sexual conflict and the mechanisms underpinning kin recognition in fly populations.


Behaviour ◽  
2019 ◽  
Vol 156 (11) ◽  
pp. 1127-1149
Author(s):  
T.N. Wittman ◽  
B.H. King

Abstract In haplodiploid species, daughter production, but not son production, is sexual, requiring paternal contributions. Females may use male signals to choose a mate with better daughter-production potential, if the choice facilitates her production of adaptive sex ratios, e.g., female-biased sex ratios in systems operating under local mate competition (LMC). In the parasitoid wasp Urolepis rufipes, females preferred pheromone markings from males that had mated once versus multiply, were young rather than old, and were uninfected rather than infected when infection was low, but not when infection was high. Mates of singly-mated males had more female-biased offspring sex ratios than those of multiply-mated males, whereas there was no difference for mates of young versus old males. Thus, female preference for singly-mated males appears to provide indirect fitness benefits. A preference for young males, was not beneficial in the laboratory, but in nature young males may have mated less.


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