The ontogenetic development of orientation capabilities

The effects of celestial references on the navigation ability of birds are discussed. Tests were conducted in a planetarium with indigo buntings to determine the amount of stellar pattern which could be removed before disorientation occurred. It was determined that young birds have a predisposition to respond to the apparent rotational motion of the night sky. It was concluded that the peak in responsiveness to rotational information is presented during the first summer of life, prior to the first migration season

Why Does the Cognitive Reflection Test (Sometimes) Predict Utilitarian Moral Judgment (and Other Things)?

The Cognitive Reflection Test (CRT) is thought to correlate with measures of utilitarian moral judgment because it measures system-2 correction of an initial intuitive response. And some theories of moral judgment hold that the same thing often happens when people arrive a utilitarian judgments. We find, however, that CRT-type items (using logic as well as arithmetic) can work just as well when they do not have obvious intuitive answers at predicting utilitarian moral judgment, assessed with self-report questionnaires as well as with hypothetical scenarios, and also at predicting a measure of actively open-minded thinking (AOT). Moreover, long response times, as well as high accuracy, also predict moral judgment and other outcomes. The CRT might thus be considered a test of reflection-impulsivity (RI). However, RI is only part of AOT, because RI is concerned only with the amount of thinking, not its direction. Tests of AOT also predict utilitarian moral judgments. Individual differences in AOT and moral judgments are both strongly (negatively) associated with belief that morality comes from God and cannot be understood through thought. The correlation of CRT and utilitarian judgment, when found, is thus likely due to the (imperfect) correlation of AOT and CRT. Intuition in these domains is thus not necessarily something that people overcome through additional thinking, but rather what they rely on when they do not think very much

Nucleosomes in serum as a marker for cell death

The concentration of nucleosomes is elevated in blood of patients with diseases which are associated with enhanced cell death. In order to detect these circulating nucleosomes, we used the Cell Death Detection-ELISA(Plus) (CDDE) from Roche Diagnostics (Mannheim, Germany) (details at http:\textbackslash{}\textbackslash{}biochem.roche.com). For its application in liquid materials we performed various modifications: we introduced a standard curve with nucleosome-rich material, which enabled direct quantification and improved comparability of the values within (CVinterassay:3.0-4.1%) and between several runs (CVinterassay:8.6-13.5%), and tested the analytical specificity of the ELISA. Because of the fast elimination of nucleosomes from circulation and their limited stability, we compared plasma and serum matrix and investigated in detail the pre-analytical handling of serum samples which can considerably influence the test results. Careless venipuncture producing hemolysis, delayed centrifugation and bacterial contamination of the blood samples led to false-positive results; delayed stabilization with EDTA and insufficient storage conditions resulted in false-negative values. At temperatures of -20 degreesC, serum samples which were treated with 10 mM EDTA were stable for at least 6 months. In order to avoid possible interfering factors, we recommend a schedule for the pre-analytical handling of the samples. As the first stage, the possible clinical application was investigated in the sera of 310 persons. Patients with solid tumors (n = 220; mean = 361 Arbitrary Units (AU)) had considerably higher values than healthy persons (n = 50; mean = 30 AU; P = 0.0001) and patients with inflammatory diseases (n = 40; mean = 296 AU; p = 0.096). Within the group of patients with tumors, those in advanced stages (UICC 4) showed significantly higher values than those in early stages (UICC 1-3) (P = 0.0004)

Fitness benefits of prolonged post-reproductive lifespan in women

Most animals reproduce until they die, but in humans, females can survive long after ceasing reproduction. In theory, a prolonged post-reproductive lifespan will evolve when females can gain greater fitness by increasing the success of their offspring than by continuing to breed themselves. Although reproductive success is known to decline in old age, it is unknown whether women gain fitness by prolonging lifespan post-reproduction. Using complete multi-generational demographic records, we show that women with a prolonged post-reproductive lifespan have more grandchildren, and hence greater fitness, in pre-modern populations of both Finns and Canadians. This fitness benefit arises because post-reproductive mothers enhance the lifetime reproductive success of their offspring by allowing them to breed earlier, more frequently and more successfully. Finally, the fitness benefits of prolonged lifespan diminish as the reproductive output of offspring declines. This suggests that in female humans, selection for deferred ageing should wane when one's own offspring become post-reproductive and, correspondingly, we show that rates of female mortality accelerate as their offspring terminate reproduction

Reproductive sharing in animal societies: reproductive incentives or incomplete control by dominant breeders?

Optimal skew models explain reproductive sharing within social groups as resulting from reproductive incentives given by controlling dominants to subordinates in return for peaceful cooperation. We explore two versions of an alternative, the incomplete control model, for the evolution of reproductive sharing within groups. In this model, dominants have only limited control over the allocation of reproduction and must expend effort to increase their share of the total group output We show that, when the relatedness between dominant and subordinate is symmetrical, (1) the subordinate's fraction of reproduction either increases with, or is insensitive to, the subordinate's genetic relatedness, r, to the dominant in both versions of the incomplete control model, whereas the subordinate's fraction of reproduction decreases with increasing rin the optimal skew model, (2) the subordinate's share of reproduction in the incomplete control model must exceed that in the optimal skew model, and (3) ecological factors affecting solitary breeding success do not directly affect the subordinate's share of reproduction in incomplete control model but do in the optimal skew model. When dominant-subordinate relatedness is asymmetrical (as is often the case in parent-offspring associations), the incomplete control model predicts no reproduction by the subordinate offspring regardless of group size for groups containing any mixture of unrelated and full-sibling subordinates, whereas the optimal skew models predict that such reproduction is possible when the group size is three or more. The available evidence indicates a negative relationship between relatedness and a subordinate's reproductive share in both vertebrate and hymenopteran societies, apparently supporting the predictions of the optimal skew not incomplete control, class of models. However, such a negative relationship is not necessarily inconsistent with the incomplete control model when, as is true for some vertebrate studies, it results from a comparison of skews in genetically monogamous, nonincestuous groups of parents and their offspring (asymmetric relatednesses) with skews in groups of nonkin (symmetric relatednesses). Both models predict higher skews in parent-offspring associations. Occasional reproduction by subordinate offspring in groups of asymmetrical relatedness when such groups are larger than dyads is more consistent with the optimal skew model, however. Overall, current data on reproductive skew and its relationships to intragroup aggression and ecological constraints support the optimal skew model, but more data are needed to rule out the incomplete control model. These models are examples of two different general views of intrasocietal evolution: the tug-of-war view, in which group members engage in a struggle over resources, and the transactional view, in which group members exchange parcels of reproduction to induce beneficial behavior from each other

The Psychology of Intelligence Analysis: Drivers of Prediction Accuracy in World Politics

This article extends psychological methods and concepts into a domain that is as profoundly consequential as it is poorly understood: intelligence analysis. We report findings from a geopolitical forecasting tournament that assessed the accuracy of more than 150,000 forecasts of 743 participants on 199 events occurring over 2 years. Participants were above average in intelligence and political knowledge relative to the general population. Individual differences in performance emerged, and forecasting skills were surprisingly consistent over time. Key predictors were (a) dispositional variables of cognitive ability, political knowledge, and open-mindedness; (b) situational variables of training in probabilistic reasoning and participation in collaborative teams that shared information and discussed rationales (Mellers, Ungar, et al., 2014); and (c) behavioral variables of deliberation time and frequency of belief updating. We developed a profile of the best forecasters; they were better at inductive reasoning, pattern detection, cognitive flexibility, and open-mindedness. They had greater understanding of geopolitics, training in probabilistic reasoning, and opportunities to succeed in cognitively enriched team environments. Last but not least, they viewed forecasting as a skill that required deliberate practice, sustained effort, and constant monitoring of current affairs

Ecological genomics: steps towards unraveling the genetic basis of inducible defenses in Daphnia

Little is known about the genetic mechanisms underlying inducible defenses. Recently, the genome of Daphnia pulex, a model organism for defense studies, has been sequenced. Building on the genome information, recent preliminary studies in BMC Developmental Biology and BMC Molecular Biology have assessed gene response profiles in Daphnia under predation pressure. We review the significance of the findings and highlight future research perspectives

Till death (or an intruder) do us part: intrasexual-competition in a monogamous Primate

Polygynous animals are often highly dimorphic, and show large sex-differences in the degree of intra-sexual competition and aggression, which is associated with biased operational sex ratios (OSR). For socially monogamous, sexually monomorphic species, this relationship is less clear. Among mammals, pair-living has sometimes been assumed to imply equal OSR and low frequency, low intensity intra-sexual competition; even when high rates of intra-sexual competition and selection, in both sexes, have been theoretically predicted and described for various taxa. Owl monkeys are one of a few socially monogamous primates. Using long-term demographic and morphological data from 18 groups, we show that male and female owl monkeys experience intense intra-sexual competition and aggression from solitary floaters. Pair-mates are regularly replaced by intruding floaters (27 female and 23 male replacements in 149 group-years), with negative effects on the reproductive success of both partners. Individuals with only one partner during their life produced 25% more offspring per decade of tenure than those with two or more partners. The termination of the pair-bond is initiated by the floater, and sometimes has fatal consequences for the expelled adult. The existence of floaters and the sporadic, but intense aggression between them and residents suggest that it can be misleading to assume an equal OSR in socially monogamous species based solely on group composition. Instead, we suggest that sexual selection models must assume not equal, but flexible, context-specific, OSR in monogamous species.Wenner-Gren Foundation, L.S.B. Leakey Foundation, the National Geographic Society, National Science Foundation (BCS- 0621020), the University of Pennsylvania Research Foundation and the Zoological Society of San Diego, German Science Foundation (HU 1746-2/1

Colony-level differences in the scaling rules governing wood ant compound eye structure

Differential organ growth during development is essential for adults to maintain the correct proportions and achieve their characteristic shape. Organs scale with body size, a process known as allometry that has been studied extensively in a range of organisms. Such scaling rules, typically studied from a limited sample, are assumed to apply to all members of a population and/or species. Here we study scaling in the compound eyes of workers of the wood ant, Formica rufa, from different colonies within a single population. Workers' eye area increased with body size in all the colonies showing a negative allometry. However, both the slope and intercept of some allometric scaling relationships differed significantly among colonies. Moreover, though mean facet diameter and facet number increased with body size, some colonies primarily increased facet number whereas others increased facet diameter, showing that the cellular level processes underlying organ scaling differed among colonies. Thus, the rules that govern scaling at the organ and cellular levels can differ even within a single population