Does increased heat resistance result in higher susceptibility to predation? A test using Drosophila melanogaster selection and hardening.

Heat resistance of ectotherms can be increased both by plasticity and evolution, but these effects may have trade-offs resulting from biotic interactions. Here, we test for predation costs in Drosophila melanogaster populations with altered heat resistance produced by adult hardening and directional selection for increased heat resistance. In addition, we also tested for genetic trade-offs by testing heat resistance in lines that have evolved under increased predation risk. We show that while 35/37 °C hardening increases heat resistance as expected, it does not increase predation risk from jumping spiders or mantids; in fact, there was an indication that survival may have increased under predation following a triple 37 °C compared to a single 35 °C hardening treatment. Flies that survived a 39 °C selection cycle showed lower survival under predation, suggesting a predation cost of exposure to a more severe heat stress. There was, however, no correlated response to selection because survival did not differ between control and selected lines after selection was relaxed for one or two generations. In addition, lines selected for increased predation risk did not differ in heat resistance. Our findings suggest independent evolutionary responses to predation and heat as measured in laboratory assays, and no costs of heat hardening on susceptibility to predation.

An Acute Ocfentanil Fatality: A Case Report with Postmortem Concentrations.

A 24-year-old man known to consume illegal drugs was found dead in his apartment. A reclosable plastic zipper bag containing several hundred milligrams of a brown powder was found close to the dead body and the first assumption of the investigators was death due to heroin intoxication. Therefore, a legal autopsy was ordered. The following toxicological analysis revealed ocfentanil in urine and in the brown powder. Four different approaches for the determination of the ocfentanil concentrations in peripheral whole blood are described. Enrichment of ocfentanil from the powder was realized. With this reference, it was possible to determine the ocfentanil concentration in the seized powder to be 0.91%. Concentrations of ocfentanil were also determined in the sampled body fluids using the standard addition procedure. In peripheral blood 9.1 µg/L, in heart blood 27.9 µg/L and in urine 480 µg/L were measured. In addition, the antidepressant citalopram, the neuroleptic quetiapine and cannabinoids were found in urine and subsequently quantified in peripheral blood.

The quantitative genetic basis of adaptive divergence in the moor frog (Rana arvalis) and its implications for gene flow.

Knowledge on the relative contribution of direct genetic, maternal and environmental effects to adaptive divergence is important for understanding the drivers of biological diversification. The moor frog (Rana arvalis) shows adaptive divergence in embryonic and larval fitness traits along an acidification gradient in south-western Sweden. To understand the quantitative genetic basis of this divergence, we performed reciprocal crosses between three divergent population pairs and reared embryos and larvae at acid and neutral pH in the laboratory. Divergence in embryonic acid tolerance (survival) was mainly determined by maternal effects, whereas the relative contributions of maternal, additive and nonadditive genetic effects in larval life-history traits differed between traits, population pairs and rearing environments. These results emphasize the need to investigate the quantitative genetic basis of adaptive divergence in multiple populations and traits, as well as different environments. We discuss the implications of our findings for maintenance of local adaptation in the context of migrant and hybrid fitness.