Inclusive Fitness Research Articles

Amblyseius herbicolus mothers prefer to oviposit near eggs of non-kin in the absence of prey Carpoglyphus lactis (Acari: Phytoseiidae, Carpoglyphidae)

Many animal species can recognise and discriminate conspecifics differing in their genetic relatedness. The discrimination of kin from non-kin or more distantly related kin can benefit individuals with increased inclusive fitness and avoid adverse influences from inbreeding. A preference by mothers to oviposit near their own or closely related eggs rather than ovipositing near non-kin or distantly related eggs has been observed in several phytoseiids, possibly to reduce cannibalism and allow imprinting between siblings. The phytoseiid Amblyseius herbicolus reluctantly cannibalise kin (i.e. siblings or offspring) in the presence of non-kin or more distantly related kin. This study investigated the oviposition preference of A. herbicolus females when provided with two sites, each containing either their own eggs or eggs laid by non-kin. The influence of food on such oviposition site preference is largely unknown in phytoseiids. Thus, we also examined the oviposition site choice of A. herbicolus females in the presence and absence of its prey Carpoglyphus lactis eggs. Our results demonstrated a significant influence of prey on the oviposition site preference of A. herbicolus: adults preferred to oviposit near eggs of non-kin in the absence of prey but showed no preference when C. lactis eggs were present at both sites. We suggest that A. herbicolus females preferred to oviposit near eggs of non-kin in the absence of prey to possibly avoid kin cannibalism during food stress.

In Memoriam : Edward O. Wilson (1929-2021): It All Started with Ants.

In Memoriam : Edward O. Wilson (1929-2021): It All Started with Ants.

My early encounters with Ants and Hamilton’s inclusive fitness theory

My early encounters with Ants and Hamilton’s inclusive fitness theory

Subsistence of sib altruism in different mating systems and Haldane’s arithmetic

The moral rule “Risk your life to save your family members” is, at the same time, a biological phenomenon. The prominent population geneticist, J.B.S. Haldane told his friends that he would risk his life to save two drowning brothers, but not one – so the story goes. In biological terms, Haldane’s arithmetic claims that sib altruism is evolutionarily rational, whenever by “self-sacrifice” an altruistic gene “rescues”, on average, more than one copy of itself in its lineage. Here, we derive conditions for evolutionary stability of sib altruism, using population genetic models for three mating systems (monogamy, promiscuity and polygyny) with linear and non-linear group effect on the siblings’ survival rate.We show that for all considered selection situations, the condition of evolutionary stability is equivalent to Haldane’s arithmetic. The condition for evolutionary stability is formulated in terms of genetic relatedness and the group effect on the survival probability, similarly to the classical Hamilton’s rule. We can set up a “scale of mating systems”, since in pairwise interactions the chance of evolutionary stability of sib altruism decreases in this order: monogamy, polygyny and promiscuity.Practice of marrying and siblings’ solidarity are moral rules in a secular world and in various religious traditions. These moral rules are not evolutionarily independent, in the sense that the subsistence of sib altruism is more likely in a monogamous population.

Post-mating parental behavior trajectories differ across four species of deer mice.

Among species, parental behaviors vary in their magnitude, onset relative to reproduction, and sexual dimorphism. In deer mice (genus Peromyscus), while most species are promiscuous with low paternal care, monogamy and biparental care have evolved at least twice under different ecological conditions. Here, in a common laboratory setting, we monitored parental behaviors of males and females of two promiscuous (eastern deer mouse P. maniculatus and white-footed mouse P. leucopus) and two monogamous (oldfield mouse P. polionotus and California mouse P. californicus) species from before mating to after giving birth. In the promiscuous species, females showed parental behaviors largely after parturition, while males showed little parental care. In contrast, both sexes of monogamous species performed parental behaviors. However, while oldfield mice began to display parental behaviors before mating, California mice showed robust parental care behaviors only postpartum. These different parental-care trajectories in the two monogamous species align with their socioecology. Oldfield mice have overlapping home ranges with relatives, so infants they encounter, even if not their own, are likely to be closely related. By contrast, California mice disperse longer distances into exclusive territories with possibly unrelated neighbors, decreasing the inclusive fitness benefits of caring for unfamiliar pups before parenthood. Together, we find that patterns of parental behaviors in Peromyscus are consistent with predictions from inclusive fitness theory.

Species-specific effects and the ecological role of programmed cell death in the microalgae Ankistrodesmus (Sphaeropleales, Selenastraceae).

Reports of programmed cell death (PCD) in phytoplankton raise questions about the ecological evolutionary role of cell death in these organisms. We induced PCD by nitrogen deprivation and unregulated cell death (non-PCD) in one strain of the green microalga Ankistrodesmus densus and investigated the effects of the cell death supernatants on phylogenetically related co-occurring organisms using growth rates and maximum biomass as proxies of fitness. PCD-released materials from A. densus CCMA-UFSCar-3 significantly increased growth rates of two conspecific strains compared to healthy culture (HC) supernatants and improved the maximum biomass of all A. densus strains compared to related species. Although growth rates of non-A. densus with PCD supernatants were not statistically different from HC treatment, biomass gain was significantly reduced. Thus, the organic substances released by PCD, possibly nitrogenous compounds, could promote conspecific growth. These results support the argument that PCD may differentiate species or subtypes and increases inclusive fitness in this model unicellular chlorophyte. Further research, however, is needed to identify the responsible molecules and how they interact with cells to provide the PCD benefits.

A thelytokous predatory mite is more cannibalistic towards distant kin.

Kin recognition has been widely observed in various taxa. Cannibalism avoidance may be a strong driver for the evolution of kin recognition, as it may avoid a reduction in inclusive fitness. Kin recognition has recently been observed in a generalist phytoseiid, Amblyseius herbicolus (Acari: Phytoseiidae). This study experimentally examined the degree of relatedness needed between prey larvae and cannibal adults of A. herbicolus for the occurrence of kin discrimination. The adults were individually placed in enclosed arenas with two prey, a daughter and a more distant related larva, to observe their cannibalizing choice. The adults of A. herbicolus did not discriminate between close relatives (daughter versus niece) but preferably cannibalized more distant kin (i.e., first and second cousins once removed). Phenotype matching and familiarization seem prominent as recognition mechanisms used by A. herbicolus adults. The effect of learning on kin recognition through prior contact in A. herbicolus requires further investigation. Studies on other adaptive functions of kin recognition of A. herbicolus, such as cooperation and parental care, may provide meaningful insights.

Double Layered Priority based Gray Wolf Algorithm (PrGWO-SK) for safety management in IoT network through anomaly detection

For mitigating and managing risk failures due to Internet of Things (IoT) attacks, many Machine Learning (ML) and Deep Learning (DL) solutions have been used to detect attacks but mostly suffer from the problem of high dimensionality. The problem is even more acute for resource starved IoT nodes to work with high dimension data. Motivated by this problem, in the present work a priority based Gray Wolf Optimizer is proposed for effectively reducing the input feature vector of the dataset. At each iteration all the wolves leverage the relative importance of their leader wolves’ position vector for updating their own positions. Also, a new inclusive fitness function is hereby proposed which incorporates all the important quality metrics along with the accuracy measure. In a first, SVM is used to initialize the proposed PrGWO population and kNN is used as the fitness wrapper technique. The proposed approach is tested on NSL-KDD, DS2OS and BoTIoT datasets and the best accuracies are found to be 99.60%, 99.71% and 99.97% with number of features as 12,6 and 9 respectively which are better than most of the existing algorithms.

A Problem of Fit: Athina Rachel Tsangari and Greek “Weird Wave” Cinema

Abstract This article uses Athina Rachel Tsangari's films to interrogate and reframe the Greek “Weird Wave” film movement (largely shaped by her frequent collaborator, Yorgos Lanthimos), revealing how the wave has obscured Tsangari's feminist authorship. In general, the Weird Wave had described a cohort of films beginning around 2009 in which familial dysfunction, violence, ineffectual communication, and corporeal “weirdness” allegorize Greek political, economic, and social crises. In a kind of temporal jumble, Tsangari's first film Fit (Greece, 1994) provides instructions for reading her later, supposedly Weird Wave films. The conceptual capaciousness of the term fit, as both a film title and a concept, refracts across Tsangari's films and career at large. This article exploits wordplay around fit as a technical standard of sound and image cohesion (how image and sound fit together), as a thematic narrative preoccupation regarding space, place, and belonging (fitting in), and as a categorizing metric (fit for inclusion). Reading diegetic and extradiegetic fit in Tsangari's film and television works, including Attenberg (Greece, 2010), The Capsule (Greece, 2012), the short 24 Frames per Century (Italy, 2013), Chevalier (Greece, 2015), and Trigonometry (BBC, 2020), reveals Tsangari's authorial signature and how Tsangari's films ambivalently benefit from “wave” marketing even as their reception bears out the costs of that uncomfortable fit. Paradoxically, Tsangari's auteur signature emerges in her struggle against category, especially Weird Wave and “women's cinema” labels. In diegetic and extradiegetic negotiations of belonging, Tsangari's auteurism emerges.

The interplay of grandparental investment according to the survival status of other grandparent types

Inclusive fitness theory predicts that grandparental investment in grandchildren aims to maximise their inclusive fitness. Owing to an increasing overlap between successive generations in modern affluent populations, the importance of grandparental investment remains high. Despite the growing literature, there is limited knowledge regarding how the survival status of different grandparent types influences each other’s investment in grandchildren. This question was studied by using the Involved Grandparenting and Child Well-Being Survey, which provided nationally representative data of English and Welsh adolescents aged 11–16-years. We applied Bayesian structural equation modeling (BSEM) where grandparental investment in grandchildren was modelled using multi-indicator unobserved latent variable. Our results showed that maternal grandmothers’ investment was increased by having a living maternal grandfather but not vice versa. Having a living maternal grandmother was also associated with decreased investment of paternal grandparents while the opposite was not found. These findings indicate that the association between the survival status of other grandparents and the focal grandparents’ investment varies between grandparent types.

State Mindfulness Increases Utilitarian Decision Making but Not at the Expense of Inclusive Fitness

State Mindfulness Increases Utilitarian Decision Making but Not at the Expense of Inclusive Fitness

The effects of genetic distance, nutrient conditions, and recognition ways on outcomes of kin recognition in Glechoma longituba.

Kin recognition might help plants decrease competitive cost and improve inclusive fitness with close genes; thus it might interact with environmental factors to affect communities. Whether and how various factors, such as the genetic distance of neighbors, environmental stressors, or the way a plant recognizes its neighbors, might modify plant growth strategies remains unclear. To answer these questions, we conducted experiments in which ramets of a clonal plant, Glechoma longituba, were grown adjacent to different genetically related neighbors (clone kin / close kin / distant kin) in different nutrient conditions (high / medium / low), or with only root exudates from pre-treatment in culture solution. By comparing competitive traits, we found that: (1) kin recognition in G. longituba was enhanced with closer genetic distance; (2) the outcomes of kin recognition were influenced by the extent of nutrient shortage; (3) kin recognition helped to alleviate the nutrient shortage effect; (4) kin recognition via root exudates affected only below-ground growth. Our results provide new insights on the potential for manipulating the outcome of kin recognition by altering neighbor genetic distance, nutrient conditions and recognition ways. Moreover, kin recognition can help plants mitigate the effects of nutrient shortage, with potential implications in agricultural research.

Three laws of teleonometrics

Abstract We define teleonometrics as the theoretical and empirical study of teleonomy. We propose three laws for teleonometrics. The first law describes the hierarchical organization of teleonomic functions across biological levels from genes to individuals. According to this law, the number of goal-directed functions increases from individuals (one goal, maximizing inclusive fitness) to intermediate levels and to genes and alleles (myriad time-, space- and context-dependent goals, depending upon degrees and patterns of pleiotropy). The second law describes the operation of teleonomic functions under trade-offs, coadaptations and negative and positive pleiotropies, which are universal in biological systems. According to this law, the functions of an allele, gene or trait are described and defined by patterns of antagonistic (trading off) and compatible (coadapted) functions. The third law of teleonometrics is that the major transitions in evolution are driven by the origins of novel, emergent goals associated with functional changes and by the breaking and reshaping of trade-offs, especially by mechanisms involving increases in resources or time, and new divisions of labour or function. We illustrate the application of these laws using data from three empirical vignettes, which help to show the usefulness of teleonometric viewpoints for understanding the interfaces between function, trade-offs and dysfunctions manifest as disease.

Religious celibacy brings inclusive fitness benefits.

The influence of inclusive fitness interests on the evolution of human institutions remains unclear. Religious celibacy constitutes an especially puzzling institution, often deemed maladaptive. Here, we present sociodemographic data from an agropastoralist Buddhist population in western China, where parents sometimes sent a son to the monastery. We find that men with a monk brother father more children, and grandparents with a monk son have more grandchildren, suggesting that the practice is adaptive. We develop a model of celibacy to elucidate the inclusive fitness costs and benefits associated with this behaviour. We show that a minority of sons being celibate can be favoured if this increases their brothers' reproductive success, but only if the decision is under parental, rather than individual, control. These conditions apply to monks in our study site. Inclusive fitness considerations appear to play a key role in shaping parental preferences to adopt this cultural practice.

Extreme reproductive skew at the dawn of sociality is consistent with inclusive fitness theory but problematic for routes to eusociality.

To understand the earliest stages of social evolution, we need to identify species that are undergoing the initial steps into sociality. Amphylaeus morosus is the only unambiguously known social species in the bee family Colletidae and represents an independent origin of sociality within the Apoidea. This allows us to investigate the selective factors promoting the transition from solitary to social nesting. Using genome-wide SNP genotyping, we infer robust pedigree relationships to identify maternity of brood and intracolony relatedness for colonies at the end of the reproductive season. We show that A. morosus forms both matrifilial and full-sibling colonies, both involving complete or almost complete monopolization over reproduction. In social colonies, the reproductive primary was also the primary forager with the secondary female remaining in the nest, presumably as a guard. Social nesting provided significant protection against parasitism and increased brood survivorship in general. We show that secondary females gain large indirect fitness benefits from defensive outcomes, enough to satisfy the conditions of inclusive fitness theory, despite an over-production of males in social colonies. These results suggest an avenue to sociality that involves high relatedness and, very surprisingly, extreme reproductive skew in its earliest stages and raises important questions about the evolutionary steps in pathways to eusociality.

Kin selection theory and the design of cooperative crops.

In agriculture and plant breeding, plant traits may be favoured because they benefit neighbouring plants and ultimately increase total crop yield. This idea of promoting cooperation among crop plants has existed almost as long as W.D. Hamilton's inclusive fitness (kin selection) theory, the leading framework for explaining cooperation in biology. However, kin selection thinking has not been adequately applied to the idea of cooperative crops. Here, I give an overview of modern kin selection theory and consider how it explains three key strategies for designing cooperative crops: (1)selection for a less-competitive plant type (a 'communal ideotype'); (2) group-level selection for yield; and (3) exploiting naturally selected cooperation. The first two strategies, using artificial selection, have been successful in the past but suffer from limitations that could hinder future progress. Instead, I propose an alternative strategy and a new 'colonial ideotype' that exploits past natural selection for cooperation among the modules (e.g., branches or stems) of individual plants. More generally, I suggest that Hamiltonian agriculture-a kin selection view of agriculture and plant breeding-transforms our understanding of how to improve crops of the future.

Individual variation explains ageing patterns in a cooperatively breeding bird, the long-tailed tit Aegithalos caudatus.

Alloparental care in cooperatively breeding species may alter breeder age‐specific survival and reproduction and subsequently senescence. The helping behaviour itself might also undergo age‐related change, and decisions to help in facultative cooperative breeders are likely to be affected by individual condition.Helpers in long‐tailed tits Aegithalos caudatus assist relatives after failing to raise their own brood, with offspring from helped nests being more likely to recruit into the breeding population.Using data collected over 25 years, we examined the age trajectories of survival and reproduction in adult long‐tailed tits to determine how these were affected by the presence or absence of helpers and how helper behaviour changed with age.There was evidence for increased reproductive performance with breeder age, but no effect of age on the probability of survival. We found no evidence of significant senescent decline in survival or reproductive performance, although individuals accrued less inclusive fitness in their last year of life. Lifetime reproductive success was positively related to both reproductive life span and body mass. Within a season, breeders that were assisted by helpers enjoyed greater reproductive success through enhanced offspring recruitment in the following year. We found no evidence that age affected an individual's propensity to help, or the amount of indirect fitness accrued through helping.We found a positive correlation between life span and multiple components of reproductive success, suggesting that individual variation in quality underpins age‐related variation in fitness in this species. Helping decisions are driven by condition, and lifetime inclusive fitness of immigrants was predicted by body mass. These findings further support individual heterogeneity in quality being a major driver for fitness gains across the life course of long‐tailed tits.

First record of antipredator behavior in the gall‐forming aphid Mordwilkoja vagabunda

AbstractThe gall‐forming aphid Mordwilkoja vagabunda has been an out‐group in molecular studies of the evolution of social behavior in the Pemphigus genus, but Mordwilkoja aphids have not previously been assayed for social behavior, such as altruistic defense. This study reports experiments carried out in July in Ithaca, NY, in which nymphs (immature aphids) of M. vagabunda were video‐recorded under a stereomicroscope while they encountered pyralid moth larvae in a plastic arena. Mordwilkoja vagabunda nymphs of all instars used their legs to claw moth larvae while pressing their rostrums against the larvae, possibly to pierce the cuticle. Many of the attacking aphids were alatoid nymphs, rather than the specialized first‐instar soldiers typically observed in Pemphigus species. Mordwilkoja vagabunda nymphs moved in bursts that sometimes became synchronized among several aphids in the same vicinity. These synchronized, rhythmic movements may be antipredator defense strategies comparable to the collective twitching and kicking response observed in colonies of Aphis nerii and other aphid species. Defensive behaviors by M. vagabunda nymphs may be altruistic fortress defense strategies, which maximize the inclusive fitness of the clone.

Twin study of genetic relatedness and bereavement related measures: Updated analyses and the mediating role of grief

A Twin Loss Survey was completed by MZ and same-sex DZ twins following loss of a cotwin and nontwin relatives. Twin survivors (N = 612; MZ = 506; DZ, n = 106) included twins whose age at loss was 15 years or older. Participation age was M = 47.66 years (SD = 15.31). Hamilton's inclusive fitness theory generated two hypotheses: (1) MZ twins will recall greater grief intensity at loss than DZ twins; (2) loss of a twin will receive greater grief intensity ratings than loss of nontwin relatives. We expected females to grieve more intensely for deceased cotwins than males. Males cannot be certain a child conceived by their partner is theirs (paternity uncertainty). As such, grief for the loss of a twin brother (whose child would indirectly transmit common genes) should be reduced by surviving male twins, relative to surviving female twins. Part I: Hypotheses regarding grief intensity were supported. Part II: A structural equation model was estimated; grief significantly mediated relationships between exogenous and endogenous predictors and grief predicted greater preoccupation and less effective coping. MZ twins and females expressed greater grief intensity than DZ twins and males. Associations between genetic relatedness and grief, consistent with evolutionary-based predictions, are highlighted.

Hamilton’s rule in economic decision-making

Hamilton’s rule [W. D. Hamilton, Am. Nat. 97, 354–356 (1963); W. D. Hamilton, J. Theor. Biol. 7, 17–52 (1964)] quantifies the central evolutionary ideas of inclusive fitness and kin selection into a simple algebraic relationship. Evidence consistent with Hamilton’s rule is found in many animal species. A drawback of investigating Hamilton’s rule in these species is that one can estimate whether a given behavior is consistent with the rule, but a direct examination of the exact cutoff for altruistic behavior predicted by Hamilton is almost impossible. However, to the degree that economic resources confer survival benefits in modern society, Hamilton’s rule may be applicable to economic decision-making, in which case techniques from experimental economics offer a way to determine this cutoff. We employ these techniques to examine whether Hamilton’s rule holds in human decision-making, by measuring the dependence between an experimental subject’s maximal willingness to pay for a gift of $50 to be given to someone else and the genetic relatedness of the subject to the gift’s recipient. We find good agreement with the predictions of Hamilton’s rule. Moreover, regression analysis of the willingness to pay versus genetic relatedness, the number of years living in the same residence, age, and sex shows that almost all the variation is explained by genetic relatedness. Similar but weaker results are obtained from hypothetical questions regarding the maximal risk to her own life that the subject is willing to take in order to save the recipient’s life.