scholarly journals An animal society based on kin competition, not kin cooperation

2019 ◽  
Author(s):  
Jessica L. Vickruck ◽  
Miriam H. Richards
Keyword(s):  
Social Groups ◽  
Fitness Costs ◽  
Short Supply ◽  
Animal Society ◽  
Kin Competition ◽  
Direct Fitness ◽  
Carpenter Bees ◽  
Indirect Fitness ◽  
Strong Competition ◽  
Breeding Resources

AbstractAnimals respond to competition among kin for critical breeding resources in two ways: avoidance of direct fitness costs via dispersal of siblings to breed separately, and formation of kin-based societies in which subordinates offset direct fitness costs of breeding competition via altruism and increased indirect fitness. Here we provide the first evidence that kin competition can promote the evolution of societies based on non-kin cooperation. For eastern carpenter bees, nests are a critical breeding resource in perpetually short supply, leading to strong competition among females. Observations of individually marked and genotyped females demonstrate that sisters disperse from their natal nests to join social groups of nonrelatives. By forming social groups of non-kin, females increase their chances of successful reproduction, while avoiding the indirect fitness cost of competition among sisters.One Sentence SummaryWe describe the first known example of an animal society based on avoidance of kin competition rather than on promotion of kin cooperation.

scholarly journals Competition Drives Group Formation and Reduces Within Nest Relatedness in a Facultatively Social Carpenter Bee

2021 ◽  
Vol 9 ◽  
Author(s):  
Jess L. Vickruck ◽  
Miriam H. Richards
Keyword(s):  
Resource Sharing ◽  
Resource Competition ◽  
Group Formation ◽  
Social Groups ◽  
Fitness Costs ◽  
Short Supply ◽  
Carpenter Bee ◽  
Direct Fitness ◽  
Indirect Fitness ◽  
Almost All

Animals respond to competition among kin for critical breeding resources in two ways: avoidance of direct fitness costs via dispersal of siblings to breed separately, and formation of kin-based societies in which subordinates offset direct fitness costs of breeding competition via altruism and increased indirect fitness. In the facultatively social eastern carpenter bee, nests are a critical breeding resource in perpetually short supply, leading to strong competition among females. Observations of individually marked and genotyped females in conditions of high and low resource competition demonstrate that competition leads to resource sharing and group nesting. However, in contrast to almost all known animal societies, females avoid nesting with relatives, and disperse from their natal nests to join social groups of non-relatives. This is the first example of a structured insect society with cooperation nestmates, the majority of which are unrelated; thus cooperation is more likely based on selection for direct, rather than indirect fitness. By forming social groups of non-kin, females avoid the indirect fitness costs of kin competition among sisters, yet increase their chances of successful reproduction, and thus direct fitness, when forming colonies of non-relatives.

Age-dependent fitness costs of alarm signaling in aphids

2003 ◽  
Vol 81 (5) ◽  
pp. 757-762 ◽  
Author(s):  
Edward B Mondor ◽  
Bernard D Roitberg
Keyword(s):  
Alarm Pheromone ◽  
Fourth Instar ◽  
Fitness Cost ◽  
Fitness Costs ◽  
Alarm Signal ◽  
Offspring Production ◽  
Direct Fitness ◽  
Alarm Signaling ◽  
Pea Aphids ◽  
Age Dependent

For an alarm signal to evolve, the benefits to the signaler must outweigh the costs of sending the signal. Research has largely focused on the benefits of alarm signaling, and the costs to an organism of sending an alarm signal are not well known. When attacked by a predator, aphids secrete cornicle droplets, containing an alarm pheromone, for individual protection and to warn clonemates. As aphid alarm pheromone is synthesized de novo in a feedback loop with juvenile hormone, we hypothesized that the secretion of cornicle droplets may result in a direct fitness cost to the emitter. We show that the secretion of a single cornicle droplet by pre-reproductive (third- and fourth-instar) pea aphids, Acyrthosiphon pisum, directly altered the timing and number of offspring produced. Third-instar pea aphids delayed offspring production but produced more offspring overall than non-secreting aphids, demonstrating a life-history shift but no significant fitness cost of droplet secretion. Fourth-instar pea aphids also delayed offspring production but produced the same number of offspring as non-secretors, resulting in a direct fitness cost of droplet secretion. Offspring production by adult, reproductive pea aphids that secreted a cornicle droplet did not differ from that of non-secretors. Thus, the fitness costs of secreting cornicle droplets containing an alarm signal are age-dependent.

scholarly journals Presence of same-sex kin promotes explorative behavior in subadult cichlid fish

2020 ◽  
Vol 31 (3) ◽  
pp. 731-738 ◽  
Author(s):  
Simon Vitt ◽  
Iris Madge Pimentel ◽  
Timo Thünken
Keyword(s):  
Kin Recognition ◽  
Cichlid Fish ◽  
West African ◽  
Kin Discrimination ◽  
Same Sex ◽  
Kin Competition ◽  
Pelvicachromis Taeniatus ◽  
Indirect Fitness ◽  
Males And Females

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.

scholarly journals Males harm females less when competing with familiar relatives

2017 ◽  
Vol 284 (1867) ◽  
pp. 20171984 ◽  
Author(s):  
Samuel J. Lymbery ◽  
Leigh W. Simmons
Keyword(s):  
Egg Production ◽  
Callosobruchus Maculatus ◽  
Genetic Relatedness ◽  
Inclusive Fitness ◽  
Fitness Costs ◽  
Offspring Production ◽  
Social Familiarity ◽  
Indirect Fitness ◽  
Opposite Sex ◽  
Female Lifespan

Sexual conflict occurs when reproductive partners have different fitness optima, and can lead to the evolution of traits in one sex that inflict fitness costs on the opposite sex. Recently, it has been proposed that antagonism by males towards females should be reduced when they compete with relatives, because reducing the future productivity of a female would result in an indirect fitness cost for a harmful male. We tested this prediction in the seed beetle Callosobruchus maculatus , the males of which harm females with genital spines and pre-copulatory harassment. We compared lifespan, lifetime egg production and lifetime offspring production among females housed with groups of males that varied in their familiarity and relatedness. Females produced significantly more eggs and offspring when grouped with males who were both related and familiar to each other. There was no effect of male relatedness or familiarity on female lifespan. Our results suggest that males plastically adjust their harmfulness towards females in response to changes in inclusive fitness payoffs, and that in this species both genetic relatedness and social familiarity mediate this effect.

Male Sexual Orientation and Avuncularity in Canada: Implications for the Kin Selection Hypothesis

2011 ◽  
Vol 11 (3-4) ◽  
pp. 339-352 ◽  
Author(s):  
Deanna L. Forrester ◽  
Doug P. VanderLaan ◽  
Paul L. Vasey ◽  
Jessica L. Parker
Keyword(s):  
Kin Selection ◽  
Sexual Attraction ◽  
Altruistic Behavior ◽  
Adult Males ◽  
Social Tolerance ◽  
Fitness Costs ◽  
Future Directions ◽  
Selection Hypothesis ◽  
Indirect Fitness ◽  
Male Sexual Orientation

AbstractAndrophilia refers to sexual attraction and arousal to adult males, whereas gynephilia refers to sexual attraction and arousal to adult females. The Kin Selection Hypothesis (KSH) posits that genes for male androphilia can persist if androphilic males offset the fitness costs of not reproducing directly by enhancing indirect fitness. In theory, by directing altruistic behavior toward kin, androphilic males can increase the reproduction of kin, thereby enhancing indirect fitness. Evidence supporting the KSH has been documented in Samoa. Samoan transgendered, androphilic males, known locally as fa’afafine, are socially accepted by the majority of Samoans. In contrast, no supportive evidence has been garnered from other cultures (i.e., USA, UK, Japan) that are characterized by less social tolerance toward male androphiles. Tests of the KSH in Canada might be more likely to yield findings consistent with Samoa because Canadian social and political attitudes toward male androphiles are markedly more tolerant and accepting. Here, we compared the willingness of Canadian androphilic men, gynephilic men, and androphilic women to invest in nieces and nephews as well as in non-kin children. Consistent with the KSH and findings from Samoa, androphilic men exhibited a significantly greater cognitive dissociation between altruistic tendencies directed toward kin versus non-kin children relative to gynephilic men and androphilic women. The present study, therefore, provides some tentative support for the KSH from a culture other than Samoa. Findings and future directions for research are considered within the context of the existing cross-cultural literature.

scholarly journals The evolution of infanticide by females in mammals

2018 ◽  
Author(s):  
Dieter Lukas ◽  
Elise Huchard
Keyword(s):  
Reproductive Output ◽  
Mammalian Species ◽  
Female Aggression ◽  
Fitness Costs ◽  
Qualitative Synthesis ◽  
Female Infanticide ◽  
Taxonomic Distribution ◽  
Competitive Behaviour ◽  
Indirect Fitness ◽  
Critical Resources

AbstractIn most mammalian species, females regularly interact with kin, and it may thus be difficult to understand the evolution of some aggressive and harmful competitive behaviour among females, such as infanticide. Here, we investigate the evolutionary determinants of infanticide by females by combining a quantitative analysis of the taxonomic distribution of infanticide with a qualitative synthesis of the circumstances of infanticidal attacks in published reports. Our results show that female infanticide is widespread across mammals and varies in relation to social organization and life-history, being more frequent where females breed in groups and have intense bouts of high reproductive output. Specifically, female infanticide occurs where the proximity of conspecific offspring directly threatens the killer’s reproductive success by limiting access to critical resources for her dependent progeny, including food, shelters, care or a social position. In contrast, infanticide is not immediately modulated by the degree of kinship among females, and females occasionally sacrifice closely related juveniles. Our findings suggest that the potential direct fitness rewards of gaining access to reproductive resources have a stronger influence on the expression of female aggression than the indirect fitness costs of competing against kin.

scholarly journals Kin selection and polygyny: can relatedness lower the polygyny threshold?

2015 ◽  
Vol 2 (6) ◽  
pp. 140409 ◽  
Author(s):  
Gaute Grønstøl ◽  
Donald Blomqvist ◽  
Angela Pauliny ◽  
Richard H. Wagner
Keyword(s):  
Dna Fingerprinting ◽  
Kin Selection ◽  
Inclusive Fitness ◽  
Nest Defence ◽  
Natal Philopatry ◽  
Vanellus Vanellus ◽  
Indirect Fitness ◽  
Fitness Benefits ◽  
Breeding Resources

Resource polygyny incurs costs of having to share breeding resources for female breeders. When breeding with a relative, however, such costs may be lessened by indirect fitness benefits through kin selection, while benefits from mutualistic behaviour, such as communal defence, may increase. If so, females should be less resistant to sharing a territory with a related female than with a non-related one. We investigated whether kin selection may lower the threshold of breeding polygynously, predicting a closer relatedness between polygynous females breeding on the same territory than between females breeding on different territories. Northern lapwings, Vanellus vanellus , are suitable for testing this hypothesis as they are commonly polygynous, both sexes take part in nest defence, and the efficiency of nest defence increases with the number of defenders. Using an index of relatedness derived from DNA fingerprinting, we found that female lapwings that shared polygynous dyads were on average twice as closely related as were random females. Furthermore, relatedness did not correlate with distance between breeders, indicating that our findings cannot be explained by natal philopatry alone. Our results suggest that the polygyny threshold in lapwings may be lowered by inclusive fitness advantages of kin selection.

scholarly journals The evolution of infanticide by females in mammals

2019 ◽  
Vol 374 (1780) ◽  
pp. 20180075 ◽  
Author(s):  
Dieter Lukas ◽  
Elise Huchard
Keyword(s):  
Reproductive Output ◽  
Mammalian Species ◽  
Female Aggression ◽  
Fitness Costs ◽  
Qualitative Synthesis ◽  
Theme Issue ◽  
Female Infanticide ◽  
Competitive Behaviour ◽  
Indirect Fitness ◽  
Critical Resources

In most mammalian species, females regularly interact with kin, which is expected to reduce aggressive competitive behaviour among females. It may thus be difficult to understand why infanticide by females has been reported in numerous species and is sometimes perpetrated by groupmates. Here, we investigate the evolutionary determinants of infanticide by females by combining a quantitative analysis of the taxonomic distribution of infanticide with a qualitative synthesis of the circumstances of infanticidal attacks in published reports. Our results show that female infanticide is widespread across mammals and varies in relation to social organization and life history, being more frequent where females breed in groups and have intense bouts of high reproductive output. Specifically, female infanticide occurs where the proximity of conspecific offspring directly threatens the killer's reproductive success by limiting access to critical resources for her dependent progeny, including food, shelters, care or a social position. By contrast, infanticide is not immediately modulated by the degree of kinship among females, and females occasionally sacrifice closely related infants. Our findings suggest that the potential direct fitness rewards of gaining access to reproductive resources have a stronger influence on the expression of female aggression than the indirect fitness costs of competing against kin. This article is part of the theme issue ‘The evolution of female-biased kinship in humans and other mammals’.

scholarly journals Antibiotic production in Streptomyces is organized by a division of labor through terminal genomic differentiation

2020 ◽  
Vol 6 (3) ◽  
pp. eaay5781 ◽  
Author(s):  
Zheren Zhang ◽  
Chao Du ◽  
Frédérique de Barsy ◽  
Michael Liem ◽  
Apostolos Liakopoulos ◽  
...  
Keyword(s):  
Secondary Metabolites ◽  
Division Of Labor ◽  
Antibiotic Production ◽  
Streptomyces Coelicolor ◽  
Social Groups ◽  
Cooperative Groups ◽  
Fitness Costs ◽  
Individual Fitness ◽  
Group Members ◽  
Chromosomal Changes

One of the hallmark behaviors of social groups is division of labor, where different group members become specialized to carry out complementary tasks. By dividing labor, cooperative groups increase efficiency, thereby raising group fitness even if these behaviors reduce individual fitness. We find that antibiotic production in colonies of Streptomyces coelicolor is coordinated by a division of labor. We show that S. coelicolor colonies are genetically heterogeneous because of amplifications and deletions to the chromosome. Cells with chromosomal changes produce diversified secondary metabolites and secrete more antibiotics; however, these changes reduced individual fitness, providing evidence for a trade-off between antibiotic production and fitness. Last, we show that colonies containing mixtures of mutants and their parents produce significantly more antibiotics, while colony-wide spore production remains unchanged. By generating specialized mutants that hyper-produce antibiotics, streptomycetes reduce the fitness costs of secreted secondary metabolites while maximizing the yield and diversity of these products.

Sign in / Sign up

Export Citation Format

Share Document