Dispersal ability has been hypothesized to reduce intraspecific differentiation by homogenizing populations. On the other hand, long‐distance dispersers may have better opportunities to colonize novel habitats, which could result in population divergence. Using direct estimates of natal and breeding dispersal distances, we investigated the relationship between dispersal distances and: (i) population differentiation, assessed as subspecies richness; (ii) ecological plasticity, assessed as the number of habitats used for breeding; and (iii) wing size, assessed as wing length. The number of subspecies was negatively correlated with dispersal distances. This was the case also after correcting for potential confounding factors such as migration and similarity due to common ancestry. Dispersal was not a good predictor of ecological plasticity, suggesting that long‐distance dispersers do not have more opportunities to colonize novel habitats. Residual wing length was related to natal dispersal, but only for sedentary species. Overall, these results suggest that dispersal can have a homogenizing effect on populations and that low dispersal ability might promote speciation.

A considerable body of primary research has accumulated over the last 10 yr testing the relationship between developmental instability in the form of fluctuating asymmetry and performance of individuals in mating success itself or sexual attractiveness. This research comprises 146 samples from 65 studies of 42 species of four major taxa. We present the results of a meta-analysis of these studies, which demonstrates that there is indeed an overall significant, moderate negative relationship: for studies, the overall mean Pearson's r or effect size = -.42, P <.0005; for species, the overall mean r = -.34, .01 < P < .025. Based on calculated fail-safe numbers, the effect-size estimates are highly robust against any publication or reporting bias that may exist. There is considerable evidence that the magnitude of the negative correlation between fluctuating asymmetry and success related to sexual selection is greater for males than for females, when a secondary sexual trait rather than an ordinary trait is studied, with experimentation compared with observation, and for traits not involved with mobility compared with traits affecting mobility. There is also limited evidence that higher taxa may differ in effect size and that intensity of sexual selection negatively correlates with effect size.

The objectives of the study were to determine whether concurrent treatment with calcipotriol (50 microg/g) and either clobetasone 17-butyrate cream (0.5 mg/g) (moderate potency) or betamethasone 17-valerate cream (1 mg/g) (potent) or placebo (vehicle of calcipotriol) was more effective and/or caused less skin irritation than calcipotriol cream (50 microg/g) used twice daily. It was a multicentre, double-blind, parallel group study. Patients applied calcipotriol cream in the morning and either vehicle (n = 174), calcipotriol (n = 174), clobetasone (n = 175) or betamethasone creams (n = 176) in the evening for up to 8 weeks. Adverse events led to withdrawal in 20 patients (2.9%). The mean percentage change in PASI (psoriasis area and severity index) was -40.6 in the calcipotriol/vehicle group, -48.3 in the calcipotriol/calcipotriol group, -53.7 in the calcipotriol/clobetasone 17-butyrate group and -57.5 in the calcipotriol/betamethasone 17-valerate group. A statistically significant difference was seen between the four treatment groups (P = 0.006) with calcipotriol/vehicle being less effective than the other treatments. A statistically significant difference in favour of calcipotriol/betamethasone 17-valerate was seen between the calcipotriol/calcipotriol group and the calcipotriol/betamethasone 17-valerate group. The majority of adverse events were skin irritations, which were reported for 31.2% of patients treated with calcipotriol/vehicle, 34.3% of patients treated with calcipotriol twice daily and 23.8% vs. 17.1% of patients treated with calcipotriol/clobetasone 17-butyrate and calcipotriol/betamethasone 17-valerate, respectively. Skin irritation was seen statistically significantly less frequently in patients treated with calcipotriol/ clobetasone 17-butyrate or calcipotriol/betamethasone 17-valerate (P = 0.001), whereas no difference was seen between the other groups. In conclusion, calcipotriol applied twice daily was as effective as calcipotriol/clobetasone 17-butyrate, but slightly less effective than calcipotriol/betamethasone 17-valerate. The incidence of skin irritation was less for patients using concurrent corticosteroids, whereas treatment with calcipotriol/vehicle did not reduce the incidence of skin irritation when compared with calcipotriol twice daily.

Measures of developmental stability such as fluctuating asymmetry have been assumed to predict individual performance because asymmetry reflects an inability to cope with stressful situations, and because asymmetry hampers locomotion. However, the magnitude of this relationship between important fitness components (growth, fecundity, survival) and asymmetry has never been assessed. Based on a literature survey, estimates of the correlation between asymmetry and the three fitness components are presented. Pearson’s correlation coefficients weighted for sample size between asymmetry and growth, fecundity, and survival, respectively, were –0.15, –0.35, and –0.25, respectively, with all three coefficients being highly significant. All three relationships were extremely robust given very large fail‐safe numbers. The results were independent of whether studies or species were used as units of analysis. Hence asymmetry is a robust predictor of performance in fitness domains such as growth, fecundity, and survival, although only accounting for 2.1%, 12.3%, and 6.0% of the variance. This may be of importance for studies of sexual selection, but also for ecological and conservation biological studies, where the performance of individuals or groups of individuals are assessed.