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Doesn't apply.

The theory of circumscription posits that intricate, hierarchical societies arose in regions geographically isolated by barriers to migration, for example. In the world of nature, are mountains or seas more dominant? The considerable influence of this theory is offset by the lack of formal modeling, which has created hurdles for theoretical and empirical analyses. This theory corresponds with reproductive skew models from evolutionary ecology; inequality is a product of subordinates' capability to escape oppressive leaders. From these commonalities, we expand upon reproductive skew models to demonstrate the simultaneous evolution of inequality in many connected populations. Migration costs, as our research demonstrates, do not permanently limit inequality's long-term trajectory; rather, they impact the pace of its growth. Secondly, we demonstrate that levels of inequality can be mitigated when dominant entities introduce random errors, as these induce variations that cascade throughout political systems. The third point in our model clarifies the concept of circumscription by correlating it to the dimensions of a region and the connectivity amongst political bodies. In conclusion, our model helps unpack the intricate ways migration might affect the phenomenon of inequality. We examine our results through the lens of anthropological and archaeological evidence, and then suggest future research to complete the circumscription theory model. This article contributes to the overarching theme issue: 'Evolutionary ecology of inequality'.

Significant implications for societal durability and individual well-being arise from economic and political inequality's magnitude, its changes over time, and the forces that affect it. A comprehensive look at the evolution of economic and political inequality is presented here, paying particular attention to the case studies of Europe and the USA. This unfolding has been sculpted by factors that are both legal/institutional, technological, and social, which we discuss in the following analysis. This paper emphasizes the multifaceted nature of inequality's impact across generations, analyzing its transmission via wealth and inheritance, and other intergenerational relationships. Female dromedary We likewise scrutinize the existing research concerning the impact of inequality on economic expansion, well-being, and social unity. This article is included in the special issue, 'Evolutionary ecology of inequality'.

We explore three emerging frameworks aiming to interpret the historical roots of inequality. The Holocene epoch witnessed the formation of concentrated and reliable resource areas, coupled with differing wealth accumulation and inheritance patterns among individuals and families. From this perspective, the inheritance of farmland and livestock contributed to a greater disparity in wealth, arising from agricultural and pastoral practices. An alternative consideration is the difference between ideal free and ideal despotic population distributions, combined with variables that could initiate a transition from the initial to the latter disposition. Based on economic concepts, we propose a third framework. We posit that geographical differences in resource endowments, at their genesis, produced inequalities that separated insiders from outsiders. Erastin The escalating density of populations resulted in the erosion of kinship bonds and the deployment of force by residents to limit access by individuals from other areas, impeding their movement. These limitations assumed a critical role in the switch from mobile foraging to a settled lifestyle, existing before the development of agriculture. Settlement stratification, marked by the distinction between elites and commoners, resulted from prior inequalities based on insider-outsider status, as population density surged. These three distinct theoretical perspectives are considered to be supportive and collaborative in their overall impact. Though they intersect, each perspective highlights aspects and procedures overlooked by the remaining two. 'Evolutionary ecology of inequality' is the subject of this article, a part of a special issue.

Equitable social organization displays substantial interspecies variation within social mammals, but the driving forces behind its emergence and suppression are poorly understood. To test the phylogenetic conservatism of social dominance hierarchies—a measure of social inequality in animals—and evaluate the role of sex, age, or captivity in interspecific variation, this study employs a comparative evolutionary perspective. Aeromonas veronii biovar Sobria We observe a swift evolution of hierarchy steepness and directional consistency, unaffected by apparent historical constraints. Because of this exceptional variability, we next look at the numerous elements that have evolved to alleviate social inequalities. The unequal distribution of benefits from social networks, coalitionary support, and knowledge transfer perpetuates a hierarchy, benefiting specific individuals. Offspring health can be affected by nutritional access and prenatal stressors, engendering health inequities that extend through multiple generations. Generationally, the exchange of material resources, like land and money, is a critical phenomenon. Advantages are provided to those who control stone tools, food stashes, and territories. Yet, a significant number of the same social species, experiencing uneven access to food (essential for survival) and partners (for reproduction), participate in egalitarian measures like food distribution, adoption, revolutionary coalitions, forgiveness, and a dislike for injustice. By employing a variety of (in)equality mechanisms, mammals manage the conflicting factors of cost and benefit associated with living in groups. This article is one of many included in the theme issue, delving into the evolutionary ecology of inequality.

Developmental hardship in various species frequently correlates with compromised health and fitness in adulthood, relative to individuals who experienced more favorable conditions. Two prominent evolutionary explanations for early-life inequalities are Developmental Constraints models, which underscore the negative consequences of adverse early-life conditions, and Predictive Adaptive Response hypotheses, which highlight the costs associated with incorrect predictions regarding future circumstances. The task of empirically validating these hypotheses is complicated by conceptual and analytical challenges. Our approach to resolving these difficulties involves mathematical definitions for DC, PAR (with a focus on its 'external' manifestation), and related subjects. From these definitions, we present a novel statistical test that leverages quadratic regression. Simulations show that this method leads to a noteworthy improvement in differentiating between DC and PAR hypotheses relative to the existing approach, which relies on the analysis of interaction effects. The interaction effects method, as indicated by simulated data, frequently conflates PAR with DC. Conversely, the quadratic regression approach yields high sensitivity and high specificity in the detection of PAR. Our study emphasizes the importance of linking verbal and visual models to a formal mathematical analysis to reveal the developmental origins of disparities in adult outcomes. The 'Evolutionary ecology of inequality' theme includes this article, highlighting an aspect of its study.

Parental investment sequencing, as suggested by research in medicine and evolutionary biology, significantly influences the life history and well-being of offspring. We utilize the synchronous birth pattern of wild banded mongooses to empirically examine the lasting impact on offspring resulting from prenatal versus postnatal investment increases. We supplemented the diets of half of the pregnant breeding females in each group, maintaining the other half as identical controls. Two categories of offspring emerged from this manipulation, both born in synchronized litters: (i) 'prenatal boost' offspring, originating from mothers fed during gestation, and (ii) 'postnatal boost' offspring, deriving from mothers lacking prenatal nourishment but receiving extra alloparental care after birth. Adult offspring of prenatal interventions exhibited significantly extended lifespans, while those receiving postnatal interventions demonstrated enhanced lifetime reproductive success (LRS) and elevated glucocorticoid levels throughout their lives. Both experimental groups of offspring exhibited an increased LRS compared to the offspring from the unmanipulated litters. Adult weight, age at first reproduction, oxidative stress levels, and telomere lengths showed no variation between the two experimental offspring groups. In wild mammals, the separate and distinct influences of prenatal and postnatal investments on individual life history and fitness are exceptionally rare experimental observations. The 'Evolutionary ecology of inequality' theme issue encompasses this article.

Individuals and societies are interconnected by a dynamic feedback loop of influence. By adding and removing members, demographic turnover modifies the makeup and organization of groups, and social inheritance, which entails the transmission of social traits from parents to children, substantially influences social structure. I explore how these social structural forces influence and are influenced by individual outcomes. The impact of society on the individual within systems characterized by social inheritance of hierarchical roles, as witnessed in primates and spotted hyenas, is the subject of my analysis. By applying Markov chain models to empirical and simulated data, the interplay of demography and social inheritance in influencing individual hierarchy positions becomes apparent. In the intricate social structures of hyenas, demographic changes, not the striving for elevated status, are the primary drivers of hierarchical dynamics, causing a typical lifetime decline in social ranking.