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Abstract BackgroundRapid morphological change is emerging as a consequence of climate change in many systems. It is intuitive to hypothesize that temporal morphological trends are driven by the same selective pressures that have established well-known ecogeographic patterns over spatial environmental gradients (e.g., Bergman’s and Allen’s rules). However, mechanistic understanding of contemporary morphological shifts is lacking. ResultsWe combine morphological data and whole genome sequencing from a four-decade dataset in the migratory bird hermit thrush (Catharus guttatus) to test whether morphological shifts over time are accompanied by genetic change. Using genome-wide association, we identify alleles associated with body size, bill length, and wing length. Shifts in morphology and concordant shifts in morphology-associated alleles over time would support a genetic basis for the observed changes in morphology over recent decades, potentially an adaptive response to climate change. In our data, bill size decreases were paralleled by genetic shifts in bill size-associated alleles. On the other hand, alleles associated with body size showed no shift in frequency over time. ConclusionsTogether, our results show mixed support for evolutionary explanations of morphological response to climate change. Temporal shifts in alleles associated with bill size support the hypothesis that selection is driving temporal morphological trends. The lack of evidence for genetic shifts in body size alleles could be explained by a large role of plasticity or technical limitations associated with the likely polygenic architecture of body size, or both. Disentangling the mechanisms responsible for observed morphological response to changing environments will be vital for predicting future organismal and population responses to climate change. 

Summary Plasmodesmata (PD) allow direct communication across the cellulosic plant cell wall, facilitating the intercellular movement of metabolites and signaling molecules within the symplast. InArabidopsis thalianaembryos with reduced levels of the chloroplast RNA helicase ISE2, intercellular trafficking and the number of branched PD were increased. We therefore investigated the relationship between alteredISE2expression and intercellular trafficking.Gene expression analyses in Arabidopsis tissues whereISE2expression was increased or decreased identified genes associated with the metabolism of glucosinolates (GLSs) as highly affected.Concomitant with changes in the expression of GLS‐related genes, plants with abnormalISE2expression contained altered GLS metabolic profiles compared with wild‐type (WT) counterparts. Indeed, changes in the expression of GLS‐associated genes led to altered intercellular trafficking in Arabidopsis leaves. Exogenous application of GLSs but not their breakdown products also resulted in altered intercellular trafficking.These changes in trafficking may be mediated by callose levels at PD as exogenous GLS treatment was sufficient to modulate plasmodesmal callose in WT plants. Furthermore, auxin metabolism was perturbed in plants with increased indole‐type GLS levels. These findings suggest that GLSs, which are themselves transported between cells via PD, can act on PD to regulate plasmodesmal trafficking capacity. 

Abstract BackgroundOpioid overdose is the leading cause of injury-related death in the United States. Individuals who overdose outside of clinical settings have more positive clinical outcomes when they receive naloxone, an opioid antagonist, from a bystander as an early intervention before emergency personnel arrive. However, there is a gap in knowledge about successful instantaneous learning and intervention in a real-life stressful environment. The objective of this study is to explore the efficacy of different instructional delivery methods for bystanders in a stressful environment. We aim to evaluate which methods are most effective for instantaneous learning, successful intervention, and improved clinical outcomes. MethodsTo explore instantaneous learning in a stressful environment, we conducted a quantitative randomized controlled trial to measure how accurately individuals responded to memory-based survey questions guided by different instructional methods. Students from a large university in the Midwest (n = 157) were recruited in a public space on campus and accessed the six-question survey on their mobile devices. The intervention group competed the survey immediately while the research team created a distracting environment. The control group was asked to complete the survey later in a quiet environment. ResultsThe intervention group correctly answered 0.72 questions fewer than the control group (p = .000, CI [0.337, 1.103]). Questions Q1 and Q5 contained direct instructions with a verbal component and showed the greatest accuracy with over 90% correct for both stressful and controlled environments. ConclusionsThe variability in the responses suggests that there are environmental factors as well as instructional design features which influence instantaneous learning. The findings of this study begin to address the gap in knowledge about the effects of stress on instantaneous learning and the most effective types of instruction for untrained bystanders in emergency situations. 

Abstract Anthropogenic changes have altered the historical distributions of many North American taxa. As environments shift, ecological and evolutionary processes can combine in complex ways to either stimulate or inhibit range expansion. Here, we examined the role of evolution in a rapid range expansion whose ecological context has been well‐documented, Anna's Hummingbird (Calypte anna). Previous studies have suggested that theC. annarange expansion is the result of an ecological release facilitated by human‐mediated environmental changes, where access to new food sources have allowed further filling of the abiotic niche. We examined the role of gene flow and adaptation during range expansion from their native California breeding range, north into Canada and east into New Mexico and Texas, USA. Using low coverage whole genome sequencing we found high genetic diversity, low divergence, and little evidence of selection on the northern and eastern expansion fronts. Additionally, there are no clear barriers to gene flow across the native and expanded range. The lack of selective signals between core and expanded ranges could reflect (i) an absence of novel selection pressure in the expanded range (supporting the ecological release hypothesis), (ii) swamping of adaptive variation due to high gene flow, or (iii) limitations of genome scans for detecting small shifts in allele frequencies across many loci. Nevertheless, our results provide an example where strong selection is not apparent during a rapid, contemporary range shift.