A major goal of evolutionary science is to understand how biological diversity is generated and altered. Despite considerable advances, we still have limited insight into how phenotypic variation arises and is sorted by natural selection. Here we argue that an integrated view, which merges ecology, evolution and developmental biology (eco evo devo) on an equal footing, is needed to understand the multifaceted role of the environment in simultaneously determining the development of the phenotype and the nature of the selective environment, and how organisms in turn affect the environment through eco evo and eco devo feedbacks. To illustrate the usefulness of an integrated eco evo devo perspective, we connect it with the theory of resource polymorphism (i.e. the phenotypic and genetic diversification that occurs in response to variation in available resources). In so doing, we highlight fishes from recently glaciated freshwater systems as exceptionally well‐suited model systems for testing predictions of an eco evo devo framework in studies of diversification. Studies on these fishes show that intraspecific diversity can evolve rapidly, and that this process is jointly facilitated by (i) the availability of diverse environments promoting divergent natural selection; (ii) dynamic developmental processes sensitive to environmental and genetic signals; and (iii) eco evo and eco devo feedbacks influencing the selective and developmental environments of the phenotype. We highlight empirical examples and present a conceptual model for the generation of resource polymorphism – emphasizing eco evo devo, and identify current gaps in knowledge.
Aim: To explore resident and faculty perceptions of the feedback process, especially residents' feedback-seeking activities. Methods: We conducted focus groups of faculty and residents exploring experiences in giving and receiving feedback, feedbackseeking, and suggestions to support feedback-seeking. Using qualitative methods and an iterative process, all authors analyzed the transcribed audiotapes to identify and confirm themes. Results: Emerging themes fit a framework situating resident feedback-seeking as dependent on four central factors: (1) learning/ workplace culture, (2) relationships, (3) purpose/quality of feedback, (4) emotional responses to feedback. Residents and faculty agreed on many supports and barriers to feedback-seeking. Strengthening the workplace/learning culture through longitudinal experiences, use of feedback forms and explicit expectations for residents to seek feedback, coupled with providing a sense of safety and adequate time for observation and providing feedback were suggested. Tensions between faculty and resident perceptions regarding feedback-seeking related to fear of being found deficient, the emotional costs related to corrective feedback and perceptions that completing clinical work is more valued than learning. Conclusion: Resident feedback-seeking is influenced by multiple factors requiring attention to both faculty and learner roles. Further study of specific influences and strategies to mitigate the tensions will inform how best to support residents in seeking feedback.
Early behaviour can determine food intake and growth rate with important consequences for life history and survival in fishes. Egg size is known to affect growth rate of young Arctic charr but its influence on the development of behaviour is poorly documented. It is believed that egg size influence on growth and potentially on the behaviour of young fish decreases over time, minimized by the effects of social factors. Shortly after first feeding, we examined differences in mobility and foraging of Arctic charr in relation to egg size and social environment. The behaviour of juveniles from small and large eggs was compared five times over the course of development and in three different experimental settings: long‐term isolation (isolation before hatching), short‐term isolation vs. group rearing and mixed size group vs. homogeneous size groups. Egg size affected foraging behaviour and mobility of fish: fish coming from large eggs were more mobile and foraged more than fish coming from small eggs. Social environment affected foraging behaviour, mobility and space use: fish in a group were more mobile, foraged more and responded faster to food delivery than isolated fish. The interaction of egg size and social effects was seen primarily in foraging activities but did not affect mobility or space use. Large fish in groups foraged more than the three other groups: large fish in isolation, small fish in groups and small fish in isolation. Agonistic behaviour was rarely observed and there was no significant effect of group composition on agonistic behaviour. We discuss the importance of egg size and social effects at early stages of development with a focus on the evolutionary ecology of Arctic charr.
BackgroundFrail older adults are commonly prescribed antidepressants. Yet, there is little evidence to determine the efficacy and safety of antidepressants to treat depression with concomitant frailty. To better understand this issue, we examined the efficacy and safety of second-generation antidepressants for the treatment of older adults with depression and then considered implications for frailty.MethodsDue to the absence of therapeutic studies of frail older adults with depression, we conducted a systematic review and meta-analysis of double-blind, randomized controlled trials that compared antidepressants versus placebo for adults with depression, age 65 years or older. We searched PubMed/MEDLINE, Cochrane Library, reference lists from meta-analyses/studies, hand searches of publication lists, and related articles on PubMed. Outcomes included rates of response, remission, and adverse events. After evaluating the data, we applied a frailty-informed framework to consider how the evidence could be applied to frailty.ResultsNine trials were included in the meta-analysis (n = 2704). Subjects had moderate to severe depression. For older adults with depression, there was no statistically significant difference in response or remission to second-generation antidepressants compared to placebo. Response occurred in 45.3% of subjects receiving an antidepressant compared to 40.5% receiving placebo (RR 1.15, 95% CI: 0.96 – 1.37, p = 0.12, I2 = 71%). Remission occurred in 33.1% with antidepressant versus 31.3% with placebo (RR 1.10, 95% CI: 0.92 – 1.31, p = 0.30, I2 = 56%) (Figure 2 and 3). There were more withdrawals due to adverse events with antidepressants, 13% versus 5.8% (RR 2.30, 95% CI: 1.45–3.63; p < 0.001; I2 = 61%; NNH 14, 95% CI:10–28).Implications for frailtySubjects in the meta-analysis did not have obvious characteristics of frailty. Using framework questions to consider the implications of frailty, we hypothesize that, like older adults, frail individuals with depression may not respond to antidepressants. Further, observational studies suggest that those who are frail may be less responsive to antidepressants compared to the non-frail. Given the vulnerability of frailty, adverse events may be more burdensome.ConclusionsSecond-generation antidepressants have uncertain benefit for older adults with depression and cause more adverse events compared to placebo. Until further research clarifies benefit, careful consideration of antidepressant prescribing with frailty is warranted.
Gene expression during development shapes the phenotypes of individuals. Although embryonic gene expression can have lasting effects on developmental trajectories, few studies consider the role of maternal effects, such as egg size, on gene expression. Using qPCR, we characterize relative expression of 14 growth and/or skeletal promoting genes across embryonic development in Arctic charr (Salvelinus alpinus). We test to what extent their relative expression is correlated with egg size and size at early life‐stages within the study population. We predict smaller individuals to have higher expression of growth and skeletal promoting genes, due to less maternal resources (i.e., yolk) and prioritization of energy toward ossification. We found expression levels to vary across developmental stages and only three genes (Mmp9, Star, and Sgk1) correlated with individual size at a given developmental stage. Contrary to our hypothesis, expression of Mmp9 and Star showed a non‐linear relationship with size (at post fertilization and hatching, respectively), whilst Sgk1 was higher in larger embryos at hatching. Interestingly, these genes are also associated with craniofacial divergence of Arctic charr morphs. Our results indicate that early life‐stage variation in gene expression, concomitant to maternal effects, can influence developmental plasticity and potentially the evolution of resource polymorphism in fishes.
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