Selection and adaptation in human migration.

This article reviews the ways migration shapes human biology. This includes the physiological and genetic, but also socio-cultural aspects such as organization, behavior, and culture. Across disciplines I highlight the multiple levels of cultural and genetic selection whereby individuals and groups adapt to pressures along a migration timeline: the origin, transit, and destination. Generally, the evidence suggests that selective pressures and adaptations occur at the individual, family, and community levels. Consequently, across levels there are negotiations, interactions, and feedbacks that shape migration outcomes and the trajectory of evolutionary change. The rise and persistence of migration-relevant adaptations emerges as a central question, including the maintenance of cumulative culture adaptations, the persistence of "cultures of migration," as well as the individual-level physiological and cognitive adaptations applied to successful transit and settlement in novel environments.

Validity of a patient-specific percutaneous nephrolithotomy (PCNL) simulated surgical rehearsal platform: impact on patient and surgical outcomes.

INTRODUCTION: Simulators provide a safe method for improving surgical skills without the associated patient risks. Advances in rapid prototyping technology have permitted the reconstruction of patient imaging into patient-specific surgical simulations that require advanced expertise, potentially continuing the learning curve. OBJECTIVES: To evaluate the impact of preoperative high-fidelity patient-specific percutaneous nephrolithotomy hydrogel simulations on surgical and patient outcomes. MATERIALS AND METHODS: Between 2016 and 2017, a fellowship-trained endourologist performed 20 consecutive percutaneous nephrolithotomy procedures at an academic referral center. For the first ten patients, only standard review of patient imaging was completed. For the next ten patients, patient imaging was utilized to fabricate patient-specific models including pelvicalyceal system, kidney, stone, and relevant adjacent structures from hydrogel. The models were tested to confirm anatomic accuracy and material properties similar to live tissue. Full procedural rehearsals were completed 24-48 h before the real case. Surgical metrics and patient outcomes from both groups (rehearsal vs. standard) were compared. RESULTS: Significant improvements in mean fluoroscopy time, percutaneous needle access attempts, complications, and additional procedures were significantly lower in the rehearsal group (184.8 vs. 365.7 s, p < 0.001; 1.9 vs. 3.6 attempts, p < 0.001; 1 vs. 5, p < 0.001; and 1 vs. 5, p < 0.001, respectively). There were no differences in stone free rates, mean patient age, body mass index, or stone size between the two groups. CONCLUSION: This study demonstrates that patient-specific procedural rehearsal is effective reducing the experience curve for a complex endourological procedure, resulting in improved surgical performance and patient outcomes.

Multimodal cue integration in the dung beetle compass.

South African ball-rolling dung beetles exhibit a unique orientation behavior to avoid competition for food: after forming a piece of dung into a ball, they efficiently escape with it from the dung pile along a straight-line path. To keep track of their heading, these animals use celestial cues, such as the sun, as an orientation reference. Here we show that wind can also be used as a guiding cue for the ball-rolling beetles. We demonstrate that this mechanosensory compass cue is only used when skylight cues are difficult to read, i.e., when the sun is close to the zenith. This raises the question of how the beetles combine multimodal orientation input to obtain a robust heading estimate. To study this, we performed behavioral experiments in a tightly controlled indoor arena. This revealed that the beetles register directional information provided by the sun and the wind and can use them in a weighted manner. Moreover, the directional information can be transferred between these 2 sensory modalities, suggesting that they are combined in the spatial memory network in the beetle's brain. This flexible use of compass cue preferences relative to the prevailing visual and mechanosensory scenery provides a simple, yet effective, mechanism for enabling precise compass orientation at any time of the day.

Beyond Western, Educated, Industrial, Rich, and Democratic (WEIRD) Psychology: Measuring and Mapping Scales of Cultural and Psychological Distance.

In this article, we present a tool and a method for measuring the psychological and cultural distance between societies and creating a distance scale with any population as the point of comparison. Because psychological data are dominated by samples drawn from Western, educated, industrialized, rich, and democratic (WEIRD) nations, and overwhelmingly, the United States, we focused on distance from the United States. We also present distance from China, the country with the largest population and second largest economy, which is a common cultural comparison. We applied the fixation index (FST), a meaningful statistic in evolutionary theory, to the World Values Survey of cultural beliefs and behaviors. As the extreme WEIRDness of the literature begins to dissolve, our tool will become more useful for designing, planning, and justifying a wide range of comparative psychological projects. Our code and accompanying online application allow for comparisons between any two countries. Analyses of regional diversity reveal the relative homogeneity of the United States. Cultural distance predicts various psychological outcomes.

Strength of forelimb lateralization predicts motor errors in an insect.

Lateralized behaviours are widespread in both vertebrates and invertebrates, suggesting that lateralization is advantageous. Yet evidence demonstrating proximate or ultimate advantages remains scarce, particularly in invertebrates or in species with individual-level lateralization. Desert locusts (Schistocerca gregaria) are biased in the forelimb they use to perform targeted reaching across a gap. The forelimb and strength of this bias differed among individuals, indicative of individual-level lateralization. Here we show that strongly biased locusts perform better during gap-crossing, making fewer errors with their preferred forelimb. The number of targeting errors locusts make negatively correlates with the strength of forelimb lateralization. This provides evidence that stronger lateralization confers an advantage in terms of improved motor control in an invertebrate with individual-level lateralization.

Cultural group selection plays an essential role in explaining human cooperation: A sketch of the evidence.

Human cooperation is highly unusual. We live in large groups composed mostly of non-relatives. Evolutionists have proposed a number of explanations for this pattern, including cultural group selection and extensions of more general processes such as reciprocity, kin selection, and multi-level selection acting on genes. Evolutionary processes are consilient; they affect several different empirical domains, such as patterns of behavior and the proximal drivers of that behavior. In this target article, we sketch the evidence from five domains that bear on the explanatory adequacy of cultural group selection and competing hypotheses to explain human cooperation. Does cultural transmission constitute an inheritance system that can evolve in a Darwinian fashion? Are the norms that underpin institutions among the cultural traits so transmitted? Do we observe sufficient variation at the level of groups of considerable size for group selection to be a plausible process? Do human groups compete, and do success and failure in competition depend upon cultural variation? Do we observe adaptations for cooperation in humans that most plausibly arose by cultural group selection? If the answer to one of these questions is "no," then we must look to other hypotheses. We present evidence, including quantitative evidence, that the answer to all of the questions is "yes" and argue that we must take the cultural group selection hypothesis seriously. If culturally transmitted systems of rules (institutions) that limit individual deviance organize cooperation in human societies, then it is not clear that any extant alternative to cultural group selection can be a complete explanation.

Cultural group selection follows Darwin's classic syllogism for the operation of selection.

The main objective of our target article was to sketch the empirical case for the importance of selection at the level of groups on cultural variation. Such variation is massive in humans, but modest or absent in other species. Group selection processes acting on this variation is a framework for developing explanations of the unusual level of cooperation between non-relatives found in our species. Our case for cultural group selection (CGS) followed Darwin's classic syllogism regarding natural selection: If variation exists at the level of groups, if this variation is heritable, and if it plays a role in the success or failure of competing groups, then selection will operate at the level of groups. We outlined the relevant domains where such evidence can be sought and characterized the main conclusions of work in those domains. Most commentators agree that CGS plays some role in human evolution, although some were considerably more skeptical. Some contributed additional empirical cases. Some raised issues of the scope of CGS explanations versus competing ones.

Why cultural distance can promote - or impede - group-beneficial outcomes.

Quantifying the distance between cultural groups has received substantial recent interest. A key innovation, borrowed from population genetics, is the calculation of cultural FST (CFST) statistics on datasets of human culture. Measuring the variance between groups as a fraction of total variance, FST is theoretically important in additive models of cooperation. Consistent with this, recent empirical work has confirmed that high values of pairwise CFST (measuring cultural distance) strongly predict unwillingness to cooperate with strangers in coordination vignettes. As applications for CFST increase, however, there is greater need to understand its meaning in naturalistic situations beyond additive cooperation. Focusing on games with both positive and negative frequency dependence and high-diversity, mixed equilibria, we derive a simple relationship between FST and the evolution of group-beneficial traits across a broad spectrum of social interactions. Contrary to standard assumptions, this model shows why FST can have both positive and negative marginal effects on the spread of group-beneficial traits under certain realistic conditions. These results provide broader theoretical direction for empirical applications of CFST in the evolutionary study of culture.

Antiphospholipid antibody-associated non-infective mitral valve endocarditis successfully treated with medical therapy.

Non-bacterial endocarditis lesions associated with antiphospholipid antibodies (aPLs) in the absence of other criteria for antiphospholipid syndrome or systemic lupus erythematosus is termed an aPL-associated cardiac valve disease. Evidence regarding the management of this condition is sparse. A rare case is described of a 20-year-old female who presented with an incidental finding of 'vegetations on a heart valve'. Echocardiography revealed mitral valve leaflet thickening and echodensities with moderate mitral regurgitation. She had an elevated partial thromboplastin time that did not correct with a mixing study, and elevated levels of antiocardiolipin antibodies. Hence, a diagnosis of aPL-associated cardiac valve disease was made, and the patient commenced on warfarin, hydroxychloroquine, and a short course of oral prednisone. At one year after diagnosis the patient remained symptom-free, and follow up echocardiography revealed resolution of the vegetations with minimal mitral regurgitation. Further evidence is needed to guide the therapy of this rare condition.

Does personal experience with COVID-19 impact investment decisions? Evidence from a survey of US retail investors.

This paper explores the link between personal experience with COVID-19 and US retail investors' financial decision-making during the first COVID-19 wave. Do retail investors that have personally experienced COVID-19 change their investments after the pandemic outbreak, and if so, why? We use a cross-sectional dataset from an online survey of US retail investors collected in July and August 2020 to assess if and how respondents change their investment decisions after the COVID-19 outbreak. On average retail investors increase their investments during the first wave of COVID-19 by 4.7%, while many of them decrease their investments suggesting a high heterogeneity of investor behaviours. We provide the first evidence that personal experience with the virus can have unexpected positive effects on retail investments. Investors who have personal experience with COVID-19, who are in a vulnerable health category, who tested positive, and who know someone in their close circle of friends or family who died because of COVID-19, increase their investments by 12%. We explain our findings through terror management theory, salience theory and optimism bias, suggesting that reminders of mortality, focussing on selective salient investment information, and over-optimism despite personal vulnerable health contribute to the increase in retail investments. Increased levels of savings, saving goals and risk capacity are also positively associated with increased investments. Our findings are relevant to investors, regulators, and financial advisors, and highlight the importance of providing retail investors with access to investment opportunities in periods of unprecedented shocks such as COVID-19.

Culture rather than genes provides greater scope for the evolution of large-scale human prosociality.

Whether competition among large groups played an important role in human social evolution is dependent on how variation, whether cultural or genetic, is maintained between groups. Comparisons between genetic and cultural differentiation between neighboring groups show how natural selection on large groups is more plausible on cultural rather than genetic variation.

Enhanced Accuracy in Magnetic Actuation: Closed-loop Control of a Magnetic Agent with Low-Error Numerical Magnetic Model Estimation.

Magnetic actuation holds promise for wirelessly controlling small, magnetic surgical tools and may enable the next generation of ultra minimally invasive surgical robotic systems. Precise torque and force exertion are required for safe surgical operations and accurate state control. Dipole field estimation models perform well far from electromagnets but yield large errors near coils. Thus, manipulations near coils suffer from severe (10×) field modeling errors. We experimentally quantify closed-loop magnetic agent control performance by using both a highly erroneous dipole model and a more accurate numerical magnetic model to estimate magnetic forces and torques for any given robot pose in 2D. We compare experimental measurements with estimation errors for the dipole model and our finite element analysis (FEA) based model of fields near coils. With five different paths designed for this study, we demonstrate that FEA-based magnetic field modeling reduces positioning root-mean-square (RMS) errors by 48% to 79% as compared with dipole models. Models demonstrate close agreement for magnetic field direction estimation, showing similar accuracy for orientation control. Such improved magnetic modelling is crucial for systems requiring robust estimates of magnetic forces for positioning agents, particularly in force-sensitive environments like surgical manipulation.

Inheritance, ecology and the evolution of the canoes of east Oceania.

We consider patterns in the evolution of canoe technology in the eastern Pacific relative to three general processes: movement of canoe traits along the Polynesian settlement sequence, adaptations to local island environment, and post-settlement interaction between island groups. Using model selection methods on the distributions of canoe technology, we show that social and ecological covariates together consistently outperform each considered individually, though knowledge of island area and post-settlement trading spheres does not add explanatory power. In particular, decorative canoe traits are not effectively explained by either our ecological or transmission models. We also estimate negative effects from both settlement sequence and island geomorphology, consistent with the die-off of particular canoe designs on resource-rich high island groups such as Hawaii and New Zealand. This decline in measured traits may be owing to the lifting of ecological constraints on population size or building materials.

Ethnic Markers and How to Find Them : An Ethnographic Investigation of Marker Presence, Recognition, and Social Information.

Ethnic markers are a prominent organizing feature of human society when individuals engage in significant anonymous interactions. However, identifying markers in natural settings is nontrivial. Although ad hoc assignment of markers to groups is widely documented in the ethnographic literature, predicting the membership of individuals based on stylistic variation is less clear. We argue that a more systematic approach is required to satisfy the basic assumptions made in ethnic marker theory. To this end we introduce a three-step ethnographic method to assess the presence, recognition, and transmission of markers of group identity: (1) continual scans, (2) a utilization survey, and (3) a comparative classification task. Applying the method to a study of culturally significant motifs in the South Pacific Island nation of Tonga, we provide evidence that the motif set satisfies basic theoretical assumptions and thus the motifs are likely expressions for social coordination. We also found that the coordinating role of each motif is variable and requires further investigation.

Wealth transmission and inequality among hunter-gatherers.

We report quantitative estimates of intergenerational transmission and population-wide inequality for wealth measures in a set of hunter-gatherer populations. Wealth is defined broadly as factors that contribute to individual or household well-being, ranging from embodied forms such as weight and hunting success to material forms such household goods, as well as relational wealth in exchange partners. Intergenerational wealth transmission is low to moderate in these populations, but is still expected to have measurable influence on an individual's life chances. Wealth inequality (measured with Gini coefficients) is moderate for most wealth types, matching what qualitative ethnographic research has generally indicated (if not the stereotype of hunter-gatherers as extreme egalitarians). We discuss some plausible mechanisms for these patterns, and suggest ways in which future research could resolve questions about the role of wealth in hunter-gatherer social and economic life.

A measure of social coordination and group signaling in the wild.

Adaptive interactions in large populations often require honest signals of group membership to structure interactions. However, limitations to a simple mapping of groups onto stylistic and ethnosomatic variation suggest that new ways of measurement are needed to describe the work that objects do to facilitate social coordination. Means to measure the benefits to coordinating on specific objects, here called signaling value, would transition inquiry from general statement that signals play a role, to which signals play what roles in what contexts. This study introduces a method to measure the signaling value of specific objects using classification tasks. After mathematically showing how social coordination leads to greater associations in object classification, a statistical approach is derived to estimate the signaling value of objects from a triad classification task. The approach is then applied to a study of culturally salient motifs in the Pacific Island nation of Tonga and a comparison group in the US. The statistical estimates suggest a large role for social coordination for the full set of motifs, although there is a substantial range of signaling values among motifs. In light of the estimates, the cultural history of individual motifs is discussed as well as the future of this approach.

The positive effects of negative interactions: can avoidance of competitors or predators increase resource sampling by prey?

Spatial overlap between predators and prey is key to predicting their interaction strength and population dynamics. We constructed a spatially-explicit simulation model to explore how predator and prey behavioral traits and patterns of resource distribution influence spatial overlap between predators, prey, and prey resources. Predator and prey spatial association primarily followed the ideal free distribution. Departures from this model were intriguing, especially from the interactions of predator and prey behavior. When prey weakly avoided conspecifics, they associated more highly with resources when predators were present. Predators increased the rate of prey movement between patches, which increased their ability to sample their environment and aggregate in patches with high resources. When prey strongly avoided each other, predators decreased prey association with resources. That is, an increased rate of prey movement increased the probability that prey would interact and avoid each other without regard to the distribution of resources. More generally, a more highly clumped distribution of resources acted as a spatial anchor that generally increased prey, predator, and resource association. Prey tended to congregate with resources and predators generally congregated with prey.

Mechanisms related to the cardioprotective effects of protein kinase C epsilon (PKC epsilon) peptide activator or inhibitor in rat ischemia/reperfusion injury.

The role of protein kinase C epsilon (PKC epsilon) in polymorphonuclear leukocyte (PMN)-induced myocardial ischemia/reperfusion (MI/R) injury and novel-related mechanisms, such as regulation of vascular endothelium nitric oxide (NO) and hydrogen peroxide (H2O2) release from blood vessels, have not been previously evaluated. A cell-permeable PKC epsilon peptide activator (1-10 microM) significantly increased endothelial NO release from non-ischemic rat aortic segments (p < 0.01). By contrast, PKC epsilon peptide inhibitor (1-10 microM) dose-dependently decreased NO release (p < 0.01). Then, these corresponding doses of PKC epsilon activator or inhibitor were examined in MI/R. The PKC epsilon inhibitor (5 microM given during reperfusion, n=6) significantly attenuated PMN-induced postreperfused cardiac contractile dysfunction and PMN adherence/infiltration (both p < 0.01), and expression of intracellular adhesion molecule-1 (ICAM-1; p < 0.05). By contrast, only PKC epsilon activator pretreated hearts (5 muM PKC epsilon activator given before ischemia (PT), n = 6), not PKC epsilon activator given during reperfusion (5 microM, n=6) exerted significant cardioprotection (p < 0.01). Moreover, the NO synthase inhibitor, N(G)-nitro-L: -arginine methyl ester, did not block the cardioprotection of PKC epsilon inhibitor, whereas it completely abolished the cardioprotective effects of PKC epsilon activator PT. In addition, PKC epsilon inhibitor (0.4 mg/kg) significantly decreased H(2)O(2) release during reperfusion in a femoral I/R model (p < 0.01). Therefore, the cardioprotection of PKC epsilon inhibitor maybe related to attenuating ICAM-1 expression and H2O2 release during reperfusion. By contrast, the cardioprotective effects of PKC epsilon activator PT may be mediated by enhancing vascular endothelial NO release before ischemia.

Lessons in Lateralisation from the Insects.

The behavioural lateralisation of a species is thought to be influenced by social organisation. However, recent studies of insect species with different social structures suggest that traits showing both population-level and individual-level lateralisation can be found in single species. This has broad implications for our understanding of how lateralisation and handedness evolves.