The spread of inequality

The causes of socioeconomic inequality have been debated since the time of Plato. Many reasons for the development of stratification have been proposed, from the need for hierarchical control over large-scale irrigation systems to the accumulation of small differences in wealth over time via inheritance processes. However, none of these explains how unequal societies came to completely displace egalitarian cultural norms over time. Our study models demographic consequences associated with the unequal distribution of resources in stratified societies. Agent-based simulation results show that in constant environments, unequal access to resources can be demographically destabilizing, resulting in the outward migration and spread of such societies even when population size is relatively small. In variable environments, stratified societies spread more and are also better able to survive resource shortages by sequestering mortality in the lower classes. The predictions of our simulation are provided modest support by a range of existing empirical studies. In short, the fact that stratified societies today vastly outnumber egalitarian societies may not be due to the transformation of egalitarian norms and structures, but may instead reflect the more rapid migration of stratified societies and consequent conquest or displacement of egalitarian societies over time.     

Biomarker/bioindicator response profiles of organisms can help differentiate between sources of anthropogenic stressors in aquatic ecosystems

Aquatic ecosystems can be chronically stressed by multiple environmental factors which originate from a variety of point and non-point sources. In addition, these stressors may vary both spatially and temporally, and, combined with synergestic and cumulative interactions of these stressors, complicate the interpretation and evaluation of stress responses in organisms. To help identify and differentiate between sources of anthropogenic stressors in aquatic systems, a diagnostic approach based on exposure-response profiles in sentinel organisms was developed from the known effects of various anthropogenic activities on biological systems. To generate these exposure-effects profiles, biomarkers of exposure were plotted against bioindicators of corresponding effects for several major anthropogenic activities including petrochemical, pulp and paper, domestic sewage, mining operations, land-development, and agricultural activities. Biomarkers of exposure to environmental stressors varied widely depending on the type of anthropogenic activity involved. Bioindicator effects, however, including histopathological lesions, bioenergetic status, growth, reproductive impairment, and community-level endpoints were similar among several of the major anthropogenic activities because responses at these higher levels are less specific to stressors than are biomarkers. This approach appears useful for helping to identify and diagnose sources of stress in environments impacted by multiple stressors. By identifying the types and sources of environmental stressors impacting key components of biological systems, aquatic ecosystems can be more effectively protected, regulated, and managed to help improve and maintain environmental quality and ecosystem fitness.     

A Dimensional Model of Multilinear Sociocultural Evolution

Thurstone's latent-distance method was used to find the coordinates of fifty-five societies in a three-dimensional space that has level of sociocultural development as its principal axis. By assuming that the most probable evolutionary precursor of any society was of a type represented by the society at a lower level of development that showed the greatest similarity to it, societies were linked to form a branched evolutionary "tree." Its structure supported the postulate of multilinear sociocultural evolution and suggested its sequence and dynamics in three main lines of development up to the level of early civilization.     

Explaining Corporal Punishment of Children: A Cross-Cultural Study

Corporal punishment of children is a frequent child-training technique in many societies in the ethnographic record. In other societies it is infrequent or rare. Using a worldwide sample of largely preindustrial societies in this article, we test previous and new theories that might explain the variation. Our multiple regression analyses indicate that frequent corporal punishment of children is predicted by higher levels of social stratification and political integration, and long-term use of an alien currency. These findings are consistent with our theory that societies are likely to practice corporal punishment to prepare children for living in a society with native or imposed (e.g., colonial) power inequality. In addition, corporal punishment appears more likely in societies in which nonrelative caretakers help raise children. And in nonpacified societies, undemocratic political decision making and a culture of violence also predict corporal punishment of children.     

Psychosocial modifiers of response to stress

The impact of stress upon an organism is far more complex than the simple design of most stress research implies. We offer an expanded model for studying the relation of stressors to pathological outcomes, which takes into account both the adaptive capacity of the organism before the stressor occurs and the defenses marshalled in response to the stressor. The model also distinguishes among the initial responses of alarm, sustained defensive behaviors, and the relatively irreversible endstates which remain after resistance has ended. Realizing that only a multidiscomplinary approach can begin to capture the wholeness of human experience, this research paradigm anticipates that stressors, adaptive capacities, defenses, alarm reactions, and pathologial end-states will take place at the biological, psychological, interpersonal and sociocultural levels simultaneously and successively. Data on life change stress and psychological health outcomes gathered as part of the Air Traffic Controller Health Change Study are analyzed to illustrate the use of the model in identifying psychosocial and biological modifiers of response to stress.     

Intraspecific variation in the growth and survival of juvenile fish exposed to Eucalyptus leachate

Whilst changes in freshwater assemblages along gradients of environmental stress have been relatively well studied, we know far less about intraspecific variation to these same stressors. A stressor common in fresh waters worldwide is leachates from terrestrial plants. Leachates alter the physiochemical environment of fresh waters by lowering pH and dissolved oxygen and also releasing toxic compounds such as polyphenols and tannins, all of which can be detrimental to aquatic organisms. We investigated how chronic exposure to Eucalyptus leaf leachate affected the growth and survival of juvenile southern pygmy perch (Nannoperca australis) collected from three populations with different litter inputs, hydrology and observed leachate concentrations. Chronic exposure to elevated leachate levels negatively impacted growth and survival, but the magnitude of these lethal and sublethal responses was conditional on body size and source population. Bigger fish had increased survival at high leachate levels but overall slower growth rates. Body size also varied among populations and fish from the population exposed to the lowest natural leachate concentrations had the highest average stress tolerance. Significant intraspecific variation in both growth and survival caused by Eucalyptus leachate exposure indicates that the magnitude (but not direction) of these stress responses varies across the landscape. This raises the potential for leachate‐induced selection to operate at an among‐population scale. The importance of body size demonstrates that the timing of leachate exposure during ontogeny is central in determining the magnitude of biological response, with early life stages being most vulnerable. Overall, we demonstrate that Eucalyptus leachates are prevalent and potent selective agents that can trigger important sublethal impacts, beyond those associated with more familiar fish kills, and reiterate that dissolved organic carbon is more than just an energy source in aquatic environments.     

Frameworks of population obesity and the use of cultural consensus modeling in the study of environments contributing to obesity

Obesity in Eastern Europe has been linked to privilege and status prior to the collapse of communism, and to exposure to free-market economics after it. Neither formulation is a complete explanation, and it is useful to examine the potential value of other models of population obesity for the understanding of this phenomenon. These include those of: thrifty genotypes; obesogenic behaviour; obesogenic environments; nutrition transition; obesogenic culture; and biocultural interactions of genetics, environment, behaviour and culture. At the broadest level, obesity emerges from the interaction of thrifty genotype with obesogenic environment. However, defining obesogenic environments remains problematic, especially in relation to sociocultural factors. Furthermore, since different identity groups may share different values concerning the obesogenicity of the environment, a priori assumptions about group homogeneity may lead to flawed interpretations of the importance of sociocultural factors in obesogenic environments. A new way to identify cultural coherence of groups and populations in relation to environments contributing to obesity is put forward here, that of cultural consensus modeling.     

Boldness behavior and stress physiology in a novel urban environment suggest rapid correlated evolutionary adaptation

Novel or changing environments expose animals to diverse stressors that likely require coordinated hormonal and behavioral adaptations. Predicted adaptations to urban environments include attenuated physiological responses to stressors and bolder exploratory behaviors, but few studies to date have evaluated the impact of urban life on codivergence of these hormonal and behavioral traits in natural systems. Here, we demonstrate rapid adaptive shifts in both stress physiology and correlated boldness behaviors in a songbird, the dark-eyed junco, following its colonization of a novel urban environment. We compared elevation in corticosterone (CORT) in response to handling and flight initiation distances in birds from a recently established urban population in San Diego, California to birds from a nearby wildland population in the species' ancestral montane breeding range. We also measured CORT and exploratory behavior in birds raised from early life in a captive common garden study. We found persistent population differences for both reduced CORT responses and bolder exploratory behavior in birds from the colonist population, as well as significant negative covariation between maximum CORT and exploratory behavior. Although early developmental effects cannot be ruled out, these results suggest contemporary adaptive evolution of correlated hormonal and behavioral traits associated with colonization of an urban habitat.     

Putting Anthropology Back Togedier Again: The Ethnogenetic Critique of Cladistic Theory 925

Cladistic theories of human evolution, derived from biological theories of speciation, are currently being advanced to explain worldwide distributions of language, culture, and physical type. Such theories are weak and inconsistent, and inappropriate for describing evolution within the boundaries of human species. Ethnogenetic theory, based on the idea that each human society and culture is built from elements derived from two or more antecedent societies, is ethnographically and logically superior in several important respects.     

Forcible rape: An evolutionary perspective

In humans, forcible rape is usually defined as copulation achieved by violence or threat of violence without the free consent of the female. Although rape is universally considered a heinous and punishable crime, it remains a serious and growing problem in many modern cultures. Rape has been perceived as the pathological result of (1) the psychological dysfunction of individual rapists or (2) the sexism inherent in male-dominated societies. Both sociocultural hypotheses recommend that rape be controlled through the rehabilitation of diseased rapists, diseased societies, or both. Exploration of rape in nonhuman animals and a wider application of evolutionary principles to human behavior have generated an alternative evolutionary view of rape as a potentially adaptive rather than a necessarily pathological act. The expanded biological model explores both the ultimate consequences of rape, in terms of a cost/benefit analysis of its expected effects on inclusive fitness, and its immediate proximate control, in terms of the intrinsic motivating variables and external stimuli that determine its probability of occurrence for specific individuals in specific instances. Ultimately, rape is expected to occur only when its potential benefit (production of an extra offspring) exceeds its potential cost (energy expended and risk taken owing to some probability of resistance or retribution that would reduce a rapist's reproductive success). We agree with the sociocultural view that rape is a violent rather than a sexual act. Proximately, rape appears to be motivated by male hostility, with increasing hostility increasing the probability of rape. The external stimulus for rape is a sufficiently vulnerable female. Here vulnerability varies inversely with the probability and severity of resistance or retribution expected by a rapist (i.e., the expected cost of rape in inclusive fitness). Both the frequency and patterns of rape observed in nature are either equally or more consistent with the sociobiological predictions than with the sociocultural predictions. The biological perspective implies that a society can most effectively control rape by ensuring that a rapist can expect to pay a sufficient cost to outweigh any potential benefit.     

Anthropogenic pollutants: a threat to ecosystem sustainability?

Pollutants, including synthetic organic materials and heavy metals, are known to adversely affect physiological systems in all animal species studied to date. While many individual chemicals can perturb normal functions, the combined actions of multiple pollutants are of particular concern because they can exert effects even when each individual chemical is present at concentrations too low to be individually effective. The biological effects of pollutants differ greatly between species reflecting differences in the pattern of exposure, routes of uptake, metabolism following uptake, rates of accumulation and sensitivity of the target organs. Thus, understanding of the effects of pollutants on wildlife and ecosystems will require detailed study of many different species, representing a wide range of taxa. However, such studies can be informed by knowledge obtained in more controlled conditions which may indicate likely mechanisms of action and suitable endpoint measurements. Responses may be exacerbated by interactions between the effects of pollutants and environmental stressors, such as under-nutrition or osmotic stresses and so changes in such variables associated with climatic changes may exacerbate physiological responses to pollutant burdens.     

TGF-β1 stimulates cultured human fibroblasts to proliferate and produce tissue-like fibroplasia: A fibronectin matrix-dependent event

During wound repair, fibroblasts accumulate in the injured area until any defect is filled with stratified layers of cells and matrix. Such fibroplasia also occurs in many fibrotic disorders. Transforming growth factor-β (TGF-β), a promotor of granulation tissue in vivo and extracellular matrix production in vitro, is expressed during the active fibroplasia of wound healing and fibroproliferative diseases. Under usual tissue culture conditions, normal fibroblasts grow to confluence and then cease proliferation. In this study, culture conditions with TGF-β1 have been delineated that promote human fibroblasts to grow in stratified layers mimicking in vivo fibroplasia. When medium supplemented with serum, ascorbate, proline, and TGF-β was added thrice weekly to normal human dermal fibroblasts, the cells proliferated and stratified up to 16 cell layers thick within the culture dish, producing a tissue-like fibroplasia. TGF-β stimulated both DNA synthesis as measured by 1H-thymidine uptake and cell proliferation as measured by a Hoechst dye DNA assay in these postconfluent cultures. The stratification was dependent on fibronectin assembly, as demonstrated by anti-fibronectin antibodies which inhibited both basal and TGF-β-stimulated cell proliferation and stratification. Suppression of collagen matrix assembly in cell layers with β-amino-proprionitrile (BAPN) did not inhibit basal or TGF-β stimulated in vitro fibroplasia. BAPN did not interfere with fibronectin matrix assembly as judged by immunofluorescence microscopy. Thus, in concert with serum factors, TGF-β stimulates postconfluent, fibronectin matrix-dependent, fibroblast growth creating a fibroplasia-like tissue in vitro. J Cell Physiol 170:69–80, 1997 © 1997 Wiley-Liss, Inc.     

Evolutionary and Ecological Effects of Multi-Generational Exposures to Anthropogenic Stressors

Biological and ecological responses to stress are dictated by duration and frequency, as well as instantaneous magnitude. Conditional compensatory responses at the physiological and behavioral levels, referred to as ‘acclimation’, may mitigate effects on individuals experiencing brief or infrequent periods of moderate stress. However, even modest stress over extended periods may reduce the fitness of some or all exposed individuals. In this way, specific stress that persists over multiple generations will increase probabilities for extinction of populations composed of sensitive individuals. For populations whose members demonstrate variance and heritability for stressor response, this selective loss of sensitive individuals may result in populations dominated by resistant individuals. The formation of these ‘adapted’ populations may be considered an ecological compensatory mechanism to multi-generational stress. Paradoxically, the biological costs to individuals of toxicity and physiological acclimation may result in obvious signs of stress in affected wildlife populations while the costs of genetic adaptation may be more covert. It is important to consider such costs because recent evidence suggests that anthropogenic stressors have acted as powerful selection agents that have modified the composition of wildlife populations subjected for successive generational exposures to specific stressors. This essay focuses on a case study where adaptation has been demonstrated in fish populations with a history of chronic exposure to persistent, bioaccumulative and toxic environmental contaminants. Because the magnitude, breadth and long-term outcomes of such changes are unknown, ecological risk assessments that are limited in focus to short-term exposures and consequences may seriously underestimate the ecological and evolutionary impacts of anthropogenic stressors.     

Male Androphilia in the Ancestral Environment

The kin selection hypothesis posits that male androphilia (male sexual attraction to adult males) evolved because androphilic males invest more in kin, thereby enhancing inclusive fitness. Increased kin-directed altruism has been repeatedly documented among a population of transgendered androphilic males, but never among androphilic males in other cultures who adopt gender identities as men. Thus, the kin selection hypothesis may be viable if male androphilia was expressed in the transgendered form in the ancestral past. Using the Standard Cross-Cultural Sample (SCCS), we examined 46 societies in which male androphilia was expressed in the transgendered form (transgendered societies) and 146 comparison societies (non-transgendered societies). We analyzed SCCS variables pertaining to ancestral sociocultural conditions, access to kin, and societal reactions to homosexuality. Our results show that ancestral sociocultural conditions and bilateral and double descent systems were more common in transgendered than in non-transgendered societies. Across the entire sample, descent systems and residence patterns that would presumably facilitate increased access to kin were associated with the presence of ancestral sociocultural conditions. Among transgendered societies, negative societal attitudes toward homosexuality were unlikely. We conclude that the ancestral human sociocultural environment was likely conducive to the expression of the transgendered form of male androphilia. Descent systems, residence patterns, and societal reactions to homosexuality likely facilitated investments in kin by transgendered males. Given that contemporary transgendered male androphiles appear to exhibit elevated kin-directed altruism, these findings further indicate the viability of the kin selection hypothesis.     

Urban stream denitrifier communities are linked to lower functional resistance to multiple stressors associated with urbanization

The microbial communities in urban stream ecosystems are subject to complex combinations of stressors. These same microbial communities perform the critical ecosystem service of removing excess reactive nitrogen. We asked whether the denitrifying microbial communities in urban streams differ in their functional resistance to common urban stressors from communities from nonurban streams. We exposed inocula from a highly polluted urban stream and a nearby nonurban stream to three different stressors, added alone and in combination. Stressors represent the common urban impacts of thermal pollution (10°C), trace metal exposure (ionic silver (Ag⁺)), and salinization (addition of NaCl). We used reduction in nitrite (NO₂ ^?) concentrations under anaerobic conditions as a proxy for denitrification potential. Nonurban stream denitrifying microbial communities were more diverse than their urban counterparts. Denitrification potential for both communities was unaffected by exposure to any individual stressor. However, denitrification rates by the less diverse urban microbial inoculum decreased in response to combined heavy metal and salt stress, while nonurban communities were unaffected. These findings support the hypothesis that higher diversity may confer greater functional resistance in response to multiple stressors and do not support the idea that stressful conditions select for communities that are functionally resilient to multiple stressors.     

Sociobiological patterns of Arab culture

Some of the salient features of Arab culture are described and illustrated using historical and ethnographic accounts supplemented by interview data on 92 Arab-Americans. An attempt is made to explain the major features and changes in Arab culture in sociobiological terms using Dickemann's model of stratified polygynous societies as a prototype. In ancient Arabia, commercial wealth and then military plunder seem to have favored female chastity as a way of competing for large bride prices. Chastity was enforced through the claustration, veiling, genital mutilation, and early betrothal of daughters. Militarism and wife capture promoted polygyny, female infanticide, and investment in sons, who provided kin altruism, including guarding of kinswomen's chastity. In modern times the disappearance of wife capture and the persistence of claustration, polygyny, and/or early betrothal may have favored male homosexuality. This Arab model is in rough agreement with Dickemann's general model, with several demurrals. Female infanticide arose more in response to poverty and to sons' value as warriors and kin altruists, and less as a result of superfluous upper-class daughters. Also, dowry seems to have been virtually absent from Arab culture even if present in other Muslim societies. Additional features of Arab culture are examined and some general conclusions reached. Veiling may serve not only as an adjunct to claustration but also as a barrier to romantic entanglements. And a test of cross-cultural data implies that restriction of females arises from economic stratification, not from polygyny.     

The ghosts of selection past reduces the probability of plastic rescue but increases the likelihood of evolutionary rescue to novel stressors in experimental populations of wild yeast

Persistence by adaptation is called evolutionary rescue. Evolutionary rescue is more likely in populations that have been previously exposed to lower doses of the same stressor. Environmental fluctuations might also reduce the possibility of rescue, but little is known about the effect of evolutionary history on the likelihood of rescue. In this study, we hypothesised that the ubiquitous operation of generalised stress responses in many organisms increases the likelihood of rescue after exposure to other stressors. We tested this hypothesis with experimental populations that had been exposed to long‐term starvation and were then selected on different, unrelated stressors. We found that prior adaptation to starvation imposes contrary effects on the plastic and evolutionary responses of populations to subsequent stressors. When first exposed to new stressors, such populations become extinct more often. If they survive the initial exposure to the new stressors, however, they are more likely to undergo evolutionary rescue.     

Each meal matters in the exposome: Biological and community considerations in fast-food-socioeconomic associations

Advances in omics and microbiome technology have transformed the ways in which the biological consequences of life in the ‘ecological theatre' can be visualized. Exposome science examines the total accumulated environmental exposures (both detrimental and beneficial) as a means to understand the response of the ‘total organism to the total environment' over time. The repetitive stimulation of compensatory physiological responses (immune, cardiovascular, neuroendocrine) in response to stress – including sources of stress highly relevant to socioeconomic disadvantage – may lead to metabolic dysregulation and cellular damage, ultimately influencing behavior and disease. The collective toll of physiological wear and tear, known as allostatic load, is not paid equally throughout developed societies. It is paid in excess by the disadvantaged. In the context of fast-food, human and experimental research demonstrates that the biological response to a single fast-food-style meal – especially as mediated by the microbiome- is a product of the person's total lived experience, including the ability to buffer the fast-food meal-induced promotion of inflammation and oxidative stress. Emerging research indicates that each meal and its nutritional context matters. As we discuss, equal weekly visits to major fast-food outlets by the affluent and deprived do not translate into biological equivalency. Hence, debate concerning reducing fast-food outlets through policy – especially in disadvantaged neighborhoods where they are prevalent – requires a biological context. The fast-food establishment and fast-food meal – as they represent matters of food justice and press upon non-communicable disease risk – are far more than physical structures and collections of carbohydrate, fat, sugar and sodium.     

Promoting Physical Activity and Reducing Sedentary Behavior in Disadvantaged Neighborhoods: A Qualitative Study of What Women Want

Since women living in socioeconomically disadvantaged neighborhoods are more likely to be physically inactive and engage in higher levels of sedentary behavior than women living in more advantaged neighborhoods, it is important to develop and test the feasibility of strategies aimed to promote physical activity and reduce sedentary behavior amongst this high-risk target group. Thirty-seven women (aged 19–85) living in a disadvantaged neighborhood, and five key stakeholders, received a suite of potential intervention materials and completed a qualitative questionnaire assessing the perceived feasibility of strategies aimed to increase physical activity and reduce sedentary behavior. Thematic analyses were performed. Women perceived the use of a locally-relevant information booklet as a feasible strategy to increase physical activity and reduce sedentary behavior. Including weight-loss information was suggested to motivate women to be active. Half the women felt the best delivery method was mailed leaflets. Other suggestions included reference books and websites. Many women mentioned that an online activity calendar was motivational but too time-consuming to commit to. Most women preferred the information booklet as a strategy to increase physical activity/reduce sedentary behavior, yet several suggested that using the booklet together with the online calendar may be more effective. These findings make an important contribution to research informing the development of intervention strategies to increase physical activity and reduce sedentary behavior amongst women living in disadvantaged neighborhoods.