Winning the Genetic Lottery: Biasing Birth Sex Ratio Results in More Grandchildren.

Population dynamics predicts that on average parents should invest equally in male and female offspring; similarly, the physiology of mammalian sex determination is supposedly stochastic, producing equal numbers of sons and daughters. However, a high quality parent can maximize fitness by biasing their birth sex ratio (SR) to the sex with the greatest potential to disproportionately outperform peers. All SR manipulation theories share a fundamental prediction: grandparents who bias birth SR should produce more grandoffspring via the favored sex. The celebrated examples of biased birth SRs in nature consistent with SR manipulation theories provide compelling circumstantial evidence. However, this prediction has never been directly tested in mammals, primarily because the complete three-generation pedigrees needed to test whether individual favored offspring produce more grandoffspring for the biasing grandparent are essentially impossible to obtain in nature. Three-generation pedigrees were constructed using 90 years of captive breeding records from 198 mammalian species. Male and female grandparents consistently biased their birth SR toward the sex that maximized second-generation success. The most strongly male-biased granddams and grandsires produced respectively 29% and 25% more grandoffspring than non-skewing conspecifics. The sons of the most male-biasing granddams were 2.7 times as fecund as those of granddams with a 50:50 bias (similar results are seen in grandsires). Daughters of the strongest female-biasing granddams were 1.2 times as fecund as those of non-biasing females (this effect is not seen in grandsires). To our knowledge, these results are the first formal test of the hypothesis that birth SR manipulation is adaptive in mammals in terms of grandchildren produced, showing that SR manipulation can explain biased birth SR in general across mammalian species. These findings also have practical implications: parental control of birth SR has the potential to accelerate genetic loss and risk of extinction within captive populations of endangered species

Psychological and situational influences on commuter-transport-mode choice

The relative importance and relationship between psychological and situational factors in predicting commuter-transport-mode choice was tested by four hypotheses. First, the influence of individuals&rsquo; values on commuter behavior is mediated by their corresponding beliefs about the environmental threat of cars (mediation hypothesis). Second, the influence of these beliefs on behavior is moderated by individual consideration of future consequences and control beliefs (moderation hypothesis). Third, cost, time, and access factors contribute to individuals&rsquo; commuter choice (situational hypothesis). Fourth, situational and psychological factors jointly influence proenvironmental behavior (interaction hypothesis). A sample of 205 Australian university students completed a survey to measure these relationships. Regression analyses indicated support for the mediation, situational, and interaction hypotheses. It was concluded that to achieve a transport-mode shift to public transport, public policy strategies should focus on individuals&rsquo; transport-related environmental beliefs (personal control and environmental effect of cars) and situations (access to public transport at reduced cost).<br /

Investigating the Role of the Outer-Coordination Sphere in [Ni(P^Ph₂N^Ph‑R₂)₂]²⁺ Hydrogenase Mimics

A series of dipeptide substituted nickel complexes with the general formula, [Ni­(P^Ph₂N^{NNA‑amino acid/ester}₂)₂]­(BF₄)₂, have been synthesized and characterized (P₂N₂ = 1,5-diaza-3,7-diphosphacyclooctane, and the dipeptide consists of the non-natural amino acid, 3-(4-aminophenyl)­propionic acid (NNA), coupled to amino acid/esters = glutamic acid, alanine, lysine, and aspartic acid). Each of these complexes is an active electrocatalyst for H₂ production. The effects of the outer-coordination sphere on the catalytic activity for the production of H₂ were investigated; specifically, the impact of sterics, the ability of the side chain or backbone to protonate and the p<i>K</i>_a values of the amino acid side chains were studied by varying the amino acids in the dipeptide. The catalytic rates of the different dipeptide substituted nickel complexes varied by over an order of magnitude. The amino acid derivatives display the fastest rates, while esterification of the terminal carboxylic acids and side chains resulted in a decrease in the catalytic rate by 50–70%, implicating a significant role of protonated sites in the outer-coordination sphere on catalytic activity. For both the amino acid and ester derivatives, the complexes with the largest substituents display the fastest rates, indicating that catalytic activity is not hindered by steric bulk. These studies demonstrate the significant contribution that the outer-coordination sphere can have in tuning the catalytic activity of small molecule hydrogenase mimics

Grandparents who bias the sex of the offspring, have more successful offspring, gaining more grandchildren.

<p><b>A</b>) Granddams and <b>B</b>) grandsires who biased birth SR towards males had greater total success measured as total grandchildren produced (<i>P</i><0.0001; <i>P = </i>0.0108, respectively). Birth SR is shown as a <i>Z-</i>score, to control for number of F1 offspring (the X-axes also give examples of male biases for a given <i>Z-</i>score). <b>C</b>) Granddams, and <b>D</b>) grandsires, who biased birth SR towards males had greater success specifically via F1 males (for both, <i>P</i><0.0001). <b>E</b>) Granddams who biased birth SR towards females had greater success specifically via F1 females (<i>P = </i>0.0272), but no effects were found for female-biasing grandsires (<i>P</i> = 0.9426), (nor did they have more total grandchildren overall; see text). For clearer data visualization, the data were split into 10th percentiles by <i>Z-</i>score, and plotted values are least-squares means and standard errors within those percentiles. The solid line indicates the least-squares regression line partialled for the controlling variables. In <b>A</b> and <b>B</b>, the Y-axes shows F0 success as total grandchildren born. In <b>C</b>–<b>F</b>, granddam and grandsire success is shown as the grandchildren (F2) born per each of their F1offspring born of a given sex (i.e. the mean reproductive output of the F1 children of each sex).</p

Species with notably skewed Birth Sex Ratios.

<p>The variance in birth SR was figured for each species. The five species with the greatest variance (i.e. standard deviation²) in F1 birth SR for granddams and grandsires are listed. Because birth SR is expressed as <i>Z-</i>score, the expected variance for any species = 1. The observed variances are tested against the mean within-species variance in <i>Z-</i>score.</p

Values determine the (in)effectiveness of informational interventions in promoting pro-environmental behavior

Informational interventions (e.g., awareness campaigns, carbon footprint calculators) are built on the assumption that informing the public about the environmental consequences of their actions should result in increased pro-environmental intentions and behavior. However, empirical support for this reasoning is mixed. In this paper, we argue that informational interventions may succeed in improving people's knowledge about the negative environmental consequences of one's actions, but this knowledge will not gain motivational force if people do not consider protecting the environment an important personal value. In an experiment, we measured individual differences in value priorities, and either presented participants a movie clip that portrayed the negative environmental consequences of using bottled water, or a control movie. As predicted, we found that the environmental movie improved recipients' knowledge of the negative environmental impact of bottled water, but this knowledge only resulted in concomitant changes in intentions and acceptability of related policies among participants who strongly endorsed biospheric (i.e. environmental) values, while having no effect on those who care less about the environment. Interestingly, the results suggest that although informational interventions are perhaps not always successful in directly affecting less environmentally-conscious recipients, they could still have beneficial effects, because they make those who strongly care about the environment more inclined to act on their values