Inclusive Fitness Research Articles

Calculating Relatedness: A Pedigree of Definitions.

Biology can be viewed from both an organismal and a genic perspective. A good example is W.D. Hamilton's work on inclusive fitness and kin selection, which puts relatedness at the heart of our understanding of social behavior. Relatedness mediates how much an actor should value a specific behavior's effect on a relative compared to the cost incurred to itself. Despite its key explanatory role, relatedness is also a concept marred with misunderstanding. Part of the problem has been that the term has been used in different ways by different people. To help address this, we survey the history of how relatedness has been formally modeled, paying particular attention to how it is conceptualized from both a gene-centric and an organism-centric point of view.

Altruistic feeding and cell-cell signaling during bacterial differentiation actively enhance phenotypic heterogeneity.

Starvation triggers bacterial spore formation, a committed differentiation program that transforms a vegetative cell into a dormant spore. Cells in a population enter sporulation nonuniformly to secure against the possibility that favorable growth conditions, which put sporulation-committed cells at a disadvantage, may resume. This heterogeneous behavior is initiated by a passive mechanism: stochastic activation of a master transcriptional regulator. Here, we identify a cell-cell communication pathway containing the proteins ShfA (YabQ) and ShfP (YvnB) that actively promotes phenotypic heterogeneity, wherein Bacillus subtilis cells that start sporulating early use a calcineurin-like phosphoesterase to release glycerol, which simultaneously acts as a signaling molecule and a nutrient to delay nonsporulating cells from entering sporulation. This produced a more diverse population that was better poised to exploit a sudden influx of nutrients compared to those generating heterogeneity via stochastic gene expression alone. Although conflict systems are prevalent among microbes, genetically encoded cooperative behavior in unicellular organisms can evidently also boost inclusive fitness.

Testing secondary sex ratio bias hypotheses in white-tailed deer in Mississippi, USA.

Natural selection favors individuals with the highest inclusive fitness (i.e., total number of descendants). In cases where one sex is more productive, one or both parents may maximize their inclusive fitness by investing in the offspring of the more prolific sex. Such preferential production can lead to skewed sex ratios at various life history stages, including at birth, resulting in secondary sex ratio bias. Several competing hypotheses have been proposed to explain observed variation in secondary sex ratios including Fisher's frequency dependence and two hypotheses related to maternal condition: Trivers-Willard and the local resource hypotheses. Although it has been shown that maternal condition can influence the number of offspring produced in white-tailed deer, there is no consensus as to which of the hypotheses drives sex ratio bias in wild populations. Using a spatiotemporally extensive dataset of pregnant white-tailed deer from Mississippi, USA, we examined fetal sex ratio in relation to the Fisherian frequency-dependence hypothesis and hypotheses related to maternal condition. While there was a male-sex ratio bias in pregnant females that reduced in intensity with the number of offspring, there was no support for condition-related hypotheses. Instead, secondary sex ratios for white-tailed deer in Mississippi were nearly consistent with Fisherian frequency dependence. Our findings add to the body of literature on secondary sex biases in white-tailed deer and help inform sex bias ratios for a southern population of a cervid of management importance in the US.

(Amoralny) familizm: propozycja rekonceptualizacji z wykorzystaniem psychologii ewolucyjnej i międzykulturowej

In his 1958 book Moral Basis of a Backward Society, Edward Banfield introduced the term amoral familism to describe social relations and values in a poor rural community in southern Italy. In my analysis, I propose to abandon the value-laden epithet "amoral" and consider familism as an evolutionary adaptive strategy activated in times of scarcity or crises. I base the thesis of the evolutionary roots of familism on the inclusive fitness theory (Hamilton 1964) and the theory of kin and reciprocal altruism (Trivers 1971). The perspective of evolutionary psychology makes it possible to see the positive functions of familism and to propose a new biological-cultural understanding of familism. Familism has so far been diagnosed primarily "indirectly" in sociological studies of bonding (and bridging) capital and in research on social trust conducted as part of cyclical social surveys such as the World Values Survey and the European Social Survey. In the search for accurate measures of biological-cultural familism we can additionally turn to the research of cross-cultural psychologists conducted for international management. I argue that the dimension of particularism on the 7-dimensional cultural map of Fons Trompenaars and Charles Hampden-Turner (2002) and the dimension of in-group collectivism on the 9-dimensional cultural map of the GLOBE project (House et al. 2004), can valuably complement the measures used in sociological sciences and make the diagnosis of familism more reliable. Finally, I call for in-depth research on Polish familism aimed at testing whether it is possible to build bridging capital on the basis of familist bonding capital.

The Evolution of Kin Discrimination Across the Tree of Life

Kin discrimination, the differential treatment of conspecifics based on kinship, occurs across the tree of life, from animals to plants to fungi to bacteria. When kin and nonkin interact, the ability to identify kin enables individuals to increase their inclusive fitness by helping kin, harming nonkin, and avoiding inbreeding. For a given species, the strength of selection for kin discrimination mechanisms is influenced by demographic, ecological, and life-history processes that collectively determine the scope for discrimination and the payoffs from kin-biased behavior. In this review, we explore how these processes drive variation in kin discrimination across taxa, highlighting contributions of recent empirical, comparative, and theoretical work to our understanding of when, how, and why kin discrimination evolves.

Active facilitation of helper dispersal by parents and siblings in the cooperatively breeding acorn woodpecker

Offspring that delay dispersal in cooperatively breeding species have been hypothesized to gain direct fitness benefits via parental facilitation—being passively tolerated on their natal territory by their parents—thereby enjoying enhanced survival and increased probability of acquiring a breeding position in the population. Here we describe active facilitation in the acorn woodpecker (Melanerpes formicivorus) by parents and siblings assisting the dispersal of helpers in their social group. Helpers in this species compete for reproductive opportunities in “power struggles” that take place when all breeders of one sex die or disappear, creating a reproductive vacancy. Individuals compete at power struggles in coalitions of relatives, in which larger coalitions are more likely to be victorious. Based on observations of banded birds, we found that an estimated 26% of individuals competing as part of a winning coalition at a power struggle returned to their home territory at its conclusion, suggesting that they were facilitating the dispersal of kin (generally parents or siblings) that stayed to become breeders on the new territory. In at least one group, sibling facilitation was reciprocated; that is, a bird that was helped at a power struggle by a sibling joined that same sibling as part of a coalition at a subsequent power struggle. Dispersal facilitation is a novel means by which parents can nepotistically enhance the direct fitness of offspring and siblings can enhance each other’s inclusive fitness in this highly social species.Significance statementParental facilitation—being passively tolerated on the natal territory—may provide significant direct fitness benefits to helpers in cooperatively breeding species. We describe active facilitation of helper dispersal in the acorn woodpecker, where helpers compete in coalitions for reproductive opportunities at “power struggles” following the death or disappearance of all breeders of one sex. About one-fourth of individuals—including both parents and siblings—competing at power struggles were apparently facilitators who assisted related helpers by participating in the power struggle but then returned to their home territory rather than stay to breed on the new territory. In at least one group, dispersal facilitation was reciprocated; that is, a bird that was helped at a power struggle by a relative later joined that same relative as part of a coalition at a subsequent power struggle. Active dispersal facilitation by parents and siblings is an important, previously unrecognized, form of nepotistic behavior in this highly social species.

Bordering and status-harms

ABSTRACT This paper examines how everyday practices of ‘bordering’, as conceived by Yuval- Davis, Wemyss, and Cassidy (2019) as the ongoing proliferation of border sites where migrants are assessed to be fit for inclusion or exclusion, may violate moral respect by subjecting migrants to a wide array of discriminatory treatment, leading to what I call ‘status-harms’. Section II begins by providing an overview of bordering and the various forms it has taken, such as internal immigration checkpoints or even online visa application processes. Section III develops an account of comparative and non-comparative status-harms and why they constitute violations of moral respect. There, I pay special attention to comparative status-harms by proposing three conditions under which a comparative status-harm can be said to have occurred: (a) if an individual or group is singled out for disadvantageous treatment that others are not subjected to on the basis of a socially salient attribute, (b) if the attribute marks them out as inferior relative to those who are not affected thus, and (c) ascriptions of inferior status occur within a morally objectionable social hierarchy where they are targeted by hostile norms and practices centred around that attribute. I then consider how discriminatory practices of bordering routinely imposes status-harms on migrants. Section IV draws a distinction between two types of discrimination that migrants may be subjected to at border sites, which I term policy-based discrimination and procedure-based discrimination, and explores their relationship to the comparative and non-comparative status-harms suffered by migrants. I conclude in Section V.

Genetic diversity of the critically endangered Blue‐crowned laughingthrush (Garrulax courtoisi)

AbstractTo evaluate the genetic quality and provide available management strategies for Blue‐crowned laughingthrush (BCLT), fifteen polymorphic microsatellite loci were developed and applied. The genetic diversity of wild individuals was indicated to be higher than the two captive populations. The average number of alleles (5.50 ± 0.317), the number of effective alleles (3.417 ± 0.222), observed heterozygosity (0.828 ± 0.04), and genetic differentiation index (0.028 ± 0.007) of 64 wild individuals showed high genetic diversity despite drastic bottleneck and low genetic differentiation. The number of effective migrants (22.737 ± 8.318) indicated the intriguing wintering grounds may be surrounded by the breeding sites where the syncheimadia occurred in Wuyuan. Efficient conservation, winter flocking, and cooperative breeding may facilitate gene exchange and inclusive fitness. We recommend that monitoring concentrated distribution areas for BCLT should be strengthened, and geographical barriers, interference types, and the inner mechanism of distribution patterns should be further explored.

Effect of Service-Learning Physical Activity Programs on Kinesiology Students’ Attitudes Toward People With Disabilities

Background: Service-learning (SL) programs have been shown to be effective for college students in developing positive attitudes toward people with disabilities (PWDs). Such positive attitudes are particularly important for Kinesiology (KIN) students as they are trained to become future health and fitness professionals. Purpose: The present study investigated the effect of a 10-week in-person versus virtual SL program on KIN students’ attitudes toward PWD. Methodology/Approach: A pre- postintervention, three-way, analysis of variance was utilized. This 3 × 2 mixed model design was utilized to assess students’ attitudes toward PWD with three independent variables (in-person program, virtual program, and control) on two dependent variables (pre and post). Findings/Conclusions: There was significant Group × Time interaction. The between-group comparison showed a significant increase in Attitudes Toward Disabled Person scale score in the in-person SL group ( p < .05) compared to non-SL group. There were no significant differences in the virtual SL group. Implications: These results indicate that in-person SL is effective for improving students’ attitudes toward PWD, whereas virtual programs may not be as effective as in-person. In-person SL programs for KIN students may positively improve their attitudes toward PWD thus ameliorating interpersonal skills and creating more inclusive health and fitness professionals. KIN programs should consider SL programs with an emphasis on PWDs.

Altruistic feeding and cell-cell signaling during bacterial differentiation actively enhance phenotypic heterogeneity.

Starvation triggers bacterial spore formation, a committed differentiation program that transforms a vegetative cell into a dormant spore. Cells in a population enter sporulation non-uniformly to secure against the possibility that favorable growth conditions, which puts sporulation-committed cells at a disadvantage, may resume. This heterogeneous behavior is initiated by a passive mechanism: stochastic activation of a master transcriptional regulator. Here, we identify a cell-cell communication pathway that actively promotes phenotypic heterogeneity, wherein Bacillus subtilis cells that start sporulating early utilize a calcineurin-like phosphoesterase to release glycerol, which simultaneously acts as a signaling molecule and a nutrient to delay non-sporulating cells from entering sporulation. This produced a more diverse population that was better poised to exploit a sudden influx of nutrients compared to those generating heterogeneity via stochastic gene expression alone. Although conflict systems are prevalent among microbes, genetically encoded cooperative behavior in unicellular organisms can evidently also boost inclusive fitness.

The maps of meaning consciousness theory.

In simple terms, consciousness is constituted by multiple goals for action and the continuous adjudication of such goals to implement action, which is referred to as the maps of meaning (MoM) consciousness theory. The MoM theory triangulates through three parallel corollaries: action (behavior), mechanism (morphology/pathophysiology), and goals (teleology). (1) An organism's consciousness contains fluid, nested goals. These goals are not intentionality, but intersectionality, via the Darwinian byproduct of embodiment meeting the world, i.e., Darwinian inclusive fitness or randomization and then survival of the fittest. (2) These goals are formed via a gradual descent under inclusive fitness and are the abstraction of a "match" between the evolutionary environment and the organism. (3) Human consciousness implements the brain efficiency hypothesis, genetics, epigenetics, and experience-crystallized efficiencies, not necessitating best or objective but fitness, i.e., perceived efficiency based on one's adaptive environment. These efficiencies are objectively arbitrary but determine the operation and level of one's consciousness, termed as extreme thrownness. (4) Since inclusive fitness drives efficiencies in the physiologic mechanism, morphology, and behavior (action) and originates one's goals, embodiment is necessarily entangled to human consciousness as it is at the intersection of mechanism or action (both necessitating embodiment) occurring in the world that determines fitness. (5) Perception is the operant process of consciousness and is the de facto goal adjudication process of consciousness. Goal operationalization is fundamentally efficiency-based via one's unique neuronal mapping as a byproduct of genetics, epigenetics, and experience. (6) Perception involves information intake and information discrimination, equally underpinned by efficiencies of inclusive fitness via extreme thrownness. Perception is not a 'frame rate' but Bayesian priors of efficiency based on one's extreme thrownness. (7) Consciousness and human consciousness are modular (i.e., a scalar level of richness, which builds up like building blocks) and dimensionalized (i.e., cognitive abilities become possibilities as the emergent phenomena at various modularities such as the stratified factors in factor analysis). (8) The meta dimensions of human consciousness seemingly include intelligence quotient, personality (five-factor model), richness of perception intake, and richness of perception discrimination, among other potentialities. (9) Future consciousness research should utilize factor analysis to parse modularities and dimensions of human consciousness and animal models.

Fitness as the organismal performance measure guiding adaptive evolution.

A long-standing problem in evolutionary theory is to clarify in what sense (if any) natural selection cumulatively improves the design of organisms. Various concepts, such as fitness and inclusive fitness, have been proposed to resolve this problem. In addition, there have been attempts to replace the original problem with more tractable questions, such as whether a given gene or trait is favored by selection. Here, we ask what theoretical properties the concept fitness should possess to encapsulate the improvement criterion required to talk meaningfully about adaptive evolution. We argue that natural selection tends to shape phenotypes based on the causal properties of individuals and that this tendency is, therefore, best captured by a fitness concept that focuses on these properties. We highlight a fitness concept that meets this role under broad conditions but requires adjustments in our conceptual understanding of adaptive evolution. These adjustments combine elements of Dawkinsian gene selectionism and Egbert Leigh's "parliament of genes."

The Roots of Science, Technology, Engineering, and Mathematics: What Are the Evolutionary and Neural Bases of Human Mathematics and Technology?

Introduction: Neural exaptations represent descent via transitions to novel neural functions. A primary transition in human cognitive and neural evolution was from a predominantly socially oriented primate brain to a brain that also instantiates and subserves science, technology, and engineering, all of which depend on mathematics. Upon what neural substrates and upon what evolved cognitive mechanisms did human capacities for science, technology, engineering, and mathematics (STEM), and especially its mathematical underpinnings, emerge? Previous theory focuses on roles for tools, language, and arithmetic in the cognitive origins of STEM, but none of these factors appears sufficient to support the transition. Methods: In this article, I describe and evaluate a novel hypothesis for the neural origins and substrates of STEM-based cognition: that they are based in human kinship systems and human maximizing of inclusive fitness. Results: The main evidence for this hypothesis is threefold. First, as demonstrated by anthropologists, human kinship systems exhibit complex mathematical and geometrical structures that function under sets of explicit rules, and such systems and rules pervade and organize all human cultures. Second, human kinship underlies the core algebraic mechanism of evolution, maximization of inclusive fitness, quantified as personal reproduction plus the sum of all effects on reproduction of others, each multiplied by their coefficient of relatedness to self. This is the only “natural” equation expected to be represented in the human brain. Third, functional imaging studies show that kinship-related cognition activates frontal-parietal regions that are also activated in STEM-related tasks. In turn, the decision-making that integrates kinship levels with costs and benefits from alternative behaviors has recently been shown to recruit the lateral septum, a hub region that combines internal (from the prefrontal cortex, amygdala, and other regions) and external information relevant to social behavior, using a dedicated subsystem of neurons specific to kinship. Conclusions: Taken together, these lines of evidence suggest that kinship systems and kin-associated behaviors may represent exaptations for the origin of human STEM.

Empowering Women through Fitness: A Gym-Centric Physical Wellbeing Inquiry in Trichy City

This article explores the role of women’s participation in fitness activities, particularly in gym-centric settings, in promoting empowerment and physical well-being. The study investigates exercise routines, nutritional plans, and health benefits, emphasizing the multifaceted nature of fitness as a lifestyle. The research involves a diverse group of women, spanning age groups and occupations, revealing motivations centered on body shape, lifestyle, and health management. The findings highlight the importance of targeted approaches for inclusive health and fitness initiatives. Despite a predominant focus on younger age groups, the study suggests addressing gaps for older participants and promoting balanced diets. It emphasizes the essential connection between a balanced diet, exercise, and improved physical fitness. Women’s fitness is crucial for overall well-being, promoting physical health, mental resilience, and disease prevention. Proper nutrition complements fitness, playing a vital role in sustaining energy levels, enhancing muscle health, and supporting holistic women’s health. Nutritious foods we take internally and exercises externally give the body a better and healthier life cycle.

ISBAR: A Handover Nursing Strategy in Emergency Departments, Scoping Review

The present work aims to map the available scientific evidence on the benefits of using the ISBAR tool in the nursing care of acutely ill adult patients’ handover in an emergency department context. To this end, a scoping review was conducted, according to the guidelines proposed by the Joanna Briggs Institute (JBI), to answer the following research question: “What are the benefits of using the ISBAR tool in the nursing care of acutely ill adult patients’ handover in an emergency department context?” The bibliographic search was carried out during August and September 2023 in the following electronic databases: CINAHL Complete; MEDLINE Complete; Cochrane Central Register of Controlled Trials; Cochrane Database of Systematic Reviews; and Cochrane Methodology Register. Only works published between 2013 and 2023 were deemed fit for inclusion. All the included studies (9) show that ISBAR methodology, as a standardized tool for transferring nursing care in the emergency service, allows for a safe, clear, and concise transition of nursing care. The benefits relate to patient and professional safety, continuity, and quality of care, as well as patient and professional comfort, with health gains.

Linked selection and the evolution of altruism in family-structured populations.

Much research on the evolution of altruism via kin selection, group selection, and reciprocity focuses on the role of a single locus or quantitative trait. Very few studies have explored how linked selection, or selection at loci neighboring an altruism locus, impacts the evolution of altruism. While linked selection can decrease the efficacy of selection at neighboring loci, it might have other effects including promoting selection for altruism by increasing relatedness in regions of low recombination. Here, we used population genetic simulations to study how negative selection at linked loci, or background selection, affects the evolution of altruism. When altruism occurs between full siblings, we found that background selection interfered with selection on the altruistic allele, increasing its fixation probability when the altruistic allele was disfavored and reducing its fixation when the allele was favored. In other words, background selection has the same effect on altruistic genes in family-structured populations as it does on other, nonsocial, genes. This contrasts with prior research showing that linked selective sweeps can favor the evolution of cooperation, and we discuss possibilities for resolving these contrasting results.

The role of patient treatment specific expectations on the outcomes of musculoskeletal physical therapy treatment: A scoping review

AbstractBackgroundIt is unknown how well patient treatment expectations are related to outcomes within musculoskeletal physical therapy. The purpose of this scoping review was to examine the association between patient treatment expectations and outcomes following physical therapy care for musculoskeletal injury and to identify gaps in the literature on this topic.Data SourcesPubMed, CINAHL Complete, PEDro, SPORTDiscus, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and PsycINFO were searched from January 2005. Concepts represented in the search included physical therapy, patient expectations, and patient outcomes, as well as their relevant synonyms.Data Extraction and SummaryA custom spreadsheet was used to chart demographic details, study design, and key findings from eligible studies. The critical appraisal skills programme (CASP) for cohort studies was used to determine reporting comprehensiveness and fit for inclusion into the review.ResultsTwelve (12) studies were included in this review representing 1855 patients across a variety of patients with musculoskeletal disorders. Studies were most commonly secondary analyses of controlled trials (n = 10) or controlled trials (n = 2) and yielded high CASP scores. A wide range of methods were used to determine patient expectations. The impact of patient treatment expectations was mixed, with some studies indicating a positive relationship between expectation fulfilment and improved outcomes, while others indicate no such relationship.ConclusionThe relationship between treatment expectations and outcomes within musculoskeletal physical therapy practice is not clear. Future studies with planned comparisons are needed to define appropriate methods to seek patient expectations and measure outcome differences between groups based on expectation fulfilment.

Inclusive Fitness May Explain Some but Not All Benefits Derived from Helping Behavior in a Cooperatively Breeding Bird.

AbstractIn cooperative breeding systems, inclusive fitness theory predicts that nonbreeding helpers more closely related to the breeders should be more willing to provide costly alloparental care and thus have more impact on breeder fitness. In the red-cockaded woodpecker (Dryobates borealis), most helpers are the breeders' earlier offspring, but helpers do vary within groups in both relatedness to the breeders (some even being unrelated) and sex, and it can be difficult to parse their separate impacts on breeder fitness. Moreover, most support for inclusive fitness theory has been positive associations between relatedness and behavior rather than actual fitness consequences. We used functional linear models to evaluate the per capita effects of helpers of different relatedness on eight breeder fitness components measured for up to 41 years at three sites. In support of inclusive fitness theory, helpers more related to the breeding pair made greater contributions to six fitness components. However, male helpers made equal contributions to increasing prefledging survival regardless of relatedness. These findings suggest that both inclusive fitness benefits and other direct benefits may underlie helping behaviors in the red-cockaded woodpecker. Our results also demonstrate the application of an underused statistical approach to disentangle a complex ecological phenomenon.

Child and adolescent foraging: New directions in evolutionary research.

Young children and adolescents in subsistence societies forage for a wide range of resources. They often target child-specific foods, they can be very successful foragers, and they share their produce widely within and outside of their nuclear family. At the same time, while foraging, they face risky situations and are exposed to diseases that can influence their immune development. However, children's foraging has largely been explained in light of their future (adult) behavior. Here, we reinterpret findings from human behavioral ecology, evolutionary medicine and cultural evolution to center foraging children's contributions to life history evolution, community resilience and immune development. We highlight the need to foreground immediate alongside delayed benefits and costs of foraging, including inclusive fitness benefits, when discussing children's food production from an evolutionary perspective. We conclude by recommending that researchers carefully consider children's social and ecological context, develop cross-cultural perspectives, and incorporate children's foraging into Indigenous sovereignty discourse.

Toward greater realism in inclusive fitness models: the case of caste fate conflict in insect societies.

In the field of social evolution, inclusive fitness theory has been successful in making a wide range of qualitative predictions on expected patterns of cooperation and conflict. Nevertheless, outside of sex ratio theory, inclusive fitness models that make accurate quantitative predictions remain relatively rare. Past models dealing with caste fate conflict in insect societies, for example, successfully predicted that if female larvae can control their own caste fate, an excess should opt to selfishly develop as queens. Available models, however, were unable to accurately predict levels of queen production observed in Melipona bees-a genus of stingless bees where caste is self-determined-as empirically observed levels of queen production are approximately two times lower than the theoretically predicted ones. Here, we show that this discrepancy can be resolved by explicitly deriving the colony-level cost of queen overproduction from a dynamic model of colony growth, requiring the incorporation of parameters of colony growth and demography, such as the per-capita rate at which new brood cells are built and provisioned, the percentage of the queen's eggs that are female, costs linked with worker reproduction and worker mortality. Our revised model predicts queen overproduction to more severely impact colony productivity, resulting in an evolutionarily stable strategy that is approximately half that of the original model, and is shown to accurately predict actual levels of queen overproduction observed in different Melipona species. Altogether, this shows how inclusive fitness models can provide accurate quantitative predictions, provided that costs and benefits are modeled in sufficient detail and are measured precisely.