Training during a sensitive period in development may have greater effects on brain structure and behavior than training later in life. Musicians are an excellent model for investigating sensitive ...periods because training starts early and can be quantified. Previous studies suggested that early training might be related to greater amounts of white matter in the corpus callosum, but did not control for length of training or identify behavioral correlates of structural change. The current study compared white-matter organization using diffusion tensor imaging in early- and late-trained musicians matched for years of training and experience. We found that early-trained musicians had greater connectivity in the posterior midbody/isthmus of the corpus callosum and that fractional anisotropy in this region was related to age of onset of training and sensorimotor synchronization performance. We propose that training before the age of 7 years results in changes in white-matter connectivity that may serve as a scaffold upon which ongoing experience can build.
Human activity is causing wild populations to experience rapid trait change and local extirpation. The resulting effects on intraspecific variation could have substantial consequences for ecological ...processes and ecosystem services. Although researchers have long acknowledged that variation among species influences the surrounding environment, only recently has evidence accumulated for the ecological importance of variation within species. We conducted a meta-analysis comparing the ecological effects of variation within a species (intraspecific effects) with the effects of replacement or removal of that species (species effects). We evaluated direct and indirect ecological responses, including changes in abundance (or biomass), rates of ecological processes and changes in community composition. Our results show that intraspecific effects are often comparable to, and sometimes stronger than, species effects. Species effects tend to be larger for direct ecological responses (for example, through consumption), whereas intraspecific effects and species effects tend to be similar for indirect responses (for example, through trophic cascades). Intraspecific effects are especially strong when indirect interactions alter community composition. Our results summarize data from the first generation of studies examining the relative ecological effects of intraspecific variation. Our conclusions can help inform the design of future experiments and the formulation of strategies to quantify and conserve biodiversity.
Congenital tremors is a sporadic disease of neonatal pigs characterized by action-related repetitive myoclonus. A majority of outbreaks of congenital tremors have been attributed to an unidentified ...virus. The objectives of this project were to 1) detect potential pathogen(s) in samples from piglets with congenital tremors and 2) develop an infection model to reproduce disease. Using next-generation sequencing, a divergent lineage pestivirus was detected in piglets with congenital tremors. The virus was originally most closely related to a bat pestivirus but is now more closely related to a recently published novel porcine pestivirus provisionally named atypical porcine pestivirus. A quantitative real-time PCR detected the virus in samples from neonatal piglets with congenital tremors from two separate farms, but not in samples from unaffected piglets from the same farm. To fulfill the second objective, pregnant sows were inoculated with either serum containing the pestivirus or PBS (control) by intravenous and intranasal routes simultaneously with direct inoculation of fetal amniotic vesicles by ultrasound-guided surgical technique. Inoculations were performed at either 45 or 62 days of gestation. All sows inoculated with the novel pestivirus farrowed piglets affected with congenital tremors while PBS-inoculated control piglets were unaffected. Tremor severity for each piglet was scored from videos taken 0, 1 and 2 days post-farrowing. Tremor severity remained relatively constant from 0 to 2 days post-farrowing for a majority of piglets. The prevalence of congenital tremors in pestivirus-inoculated litters ranged from 57% (4 out of 7 affected piglets) to 100% (10 out of 10 affected piglets). The virus was consistently detected by PCR in tissues from piglets with congenital tremors but was not detected in control piglets. Samples positive by PCR in greater than 90% of piglets sampled included brainstem (37 out of 41), mesenteric lymph node (37 out of 41), tracheobronchial lymph node (37 out of 41), and whole blood (19 out of 20). Although the first description of congenital tremors was in 1922, this is the first reported reproduction of congenital tremors following experimental inoculation with a divergent lineage porcine pestivirus. Studies investigating disease mechanism, epidemiology, and diagnostic assay development are needed to better understand the pathophysiology of congenital tremors due to this pestivirus.
•Teens and young adults are more likely to use ENDS if their parents also use them.•Teens' and young adults' own attitudes about ENDS safety predicted their ENDS use.•Young people's attitudes about ...ENDS mattered, regardless of parent nicotine use.•Parent attitudes about ENDS safety were not related to offspring ENDS use.
Prior research has showed that parent combustible cigarette use predicts cigarette use among their offspring. This study used prospective longitudinal data from parents and offspring to test whether parent electronic nicotine delivery system (ENDS) use predicted a higher probability of ENDS use among their offspring.
Data were drawn from the Seattle Social Development Project – The Intergenerational Project (SSDP-TIP). Analyses included 295 families; 7% of parents were Native American/Alaskan Native, 18% were Asian American, 28% were African American, and 47% were European American. Multilevel modeling (in 2020) of data collected in 2015, 2016, and 2017 tested associations between parent self-reported ENDS use and concurrent self-reported ENDS use among offspring ages 10–25 years (53% female). Parent combustible cigarette use was controlled. Analyses also examined the role of parent and offspring perceptions of the safety of ENDS in predicting offspring ENDS use.
About 12% of offspring and 8% of parents reported past-month ENDS use. Parent ENDS use predicted a higher probability of child ENDS use (Odds Ratio 5.68, p = .01), even after controlling parent past month cigarette use. Beyond parent nicotine product use, offspring perceptions of ENDS safety – but not parent perceptions of ENDS safety – contributed independently to offspring probability of past-month ENDS use.
It is important for parents, health providers, and policymakers to focus on preventing ENDS use among offspring of parents who use ENDS.
Fire is an inherently evolutionary process, even though much more emphasis has been given to ecological responses of plants and their associated communities to fire.
Here, we synthesize contributions ...to a Special Feature entitled ‘Fire as a dynamic ecological and evolutionary force’ and place them in a broader context of fire research. Topics covered in this Special Feature include a perspective on the impacts of novel fire regimes on differential forest mortality, discussions on new approaches to investigate vegetation‐fire feedbacks and resulting plant syndromes, synthesis of fire impacts on plant–fungal interactions, and a meta‐analysis of arthropod community responses to fire.
We conclude by suggesting pathways forward to better understand the ecological and evolutionary consequences of fire. These include developing ecological and evolutionary databases for fire ecology, integrating hierarchical genetic structure or phylogenetic structure, and developing new experimental frameworks that limit context‐dependent outcomes.
Read the free Plain Language Summary for this article on the Journal blog.
Read the free Plain Language Summary for this article on the Journal blog.
Identifying and predicting how species ranges will shift in response to climate change is paramount for conservation and restoration. Ecological niche models are the most common method used to ...estimate potential distributions of species; however, they traditionally omit knowledge of intraspecific variation that can allow populations to respond uniquely to change. Here, we aim to test how population X environment relationships influence predicted suitable geographic distributions by comparing aggregated population-level models with species-level model predictions of suitable habitat within population ranges and across the species’ range. We also test the effect of two variable selection methods on these predictions–both addressing the possibility of local adaptation: Models were built with (a) a common set, and number, of predictors and, (b) a unique combination and number of predictors specific to each group’s training extent. Our study addresses the overarching hypothesis that populations have unique environmental niches, and specifically that (1) species-level models predict more suitable habitat within the ranges of genetic populations than individual models built from those groups, particularly when compared models are built with the same set of environmental predictors; and (2) aggregated genetic population models predict more suitable habitat across the species’ range than the species-level model, an = d this difference will increase when models are trained with individualized predictors. We found the species models predicted more habitat within population ranges for two of three genetic groups regardless of variable selection, and that aggregated population models predicted more habitat than species’ models, but that individualized predictors increased this difference. Our study emphasizes the extent to which changes to model predictions depend on the inclusion of genetic information and on the type and selection of predictors. Results from these modeling decisions can have broad implications for predicting population-level ecological and evolutionary responses to climate change.
Ecological explanations for the success and persistence of invasive species vastly outnumber evolutionary hypotheses, yet evolution is a fundamental process in the success of any species. The ...Evolution of Increased Competitive Ability (EICA) hypothesis (Blossey and Nötzold 1995) proposes that evolutionary change in response to release from coevolved herbivores is responsible for the success of many invasive plant species. Studies that evaluate this hypothesis have used different approaches to test whether invasive populations allocate fewer resources to defense and more to growth and competitive ability than do source populations, with mixed results. We conducted a meta‐analysis of experimental tests of evolutionary change in the context of EICA. In contrast to previous reviews, there was no support across invasive species for EICA's predictions regarding defense or competitive ability, although invasive populations were more productive than conspecific native populations under noncompetitive conditions. We found broad support for genetically based changes in defense and competitive plant traits after introduction into new ranges, but not in the manner suggested by EICA. This review suggests that evolution occurs as a result of plant introduction and population expansion in invasive plant species, and may contribute to the invasiveness and persistence of some introduced species.
We conducted a meta‐analysis of defense and competitive traits of invasive plant species to assess support for the Evolution of Increased Competitive Ability (EICA) hypothesis. There is no general trend across species of evolutionary reductions in defense, and evolutionary enhancement of competitive traits occured only for vegetative growth traits, not for fitness‐related traits. However, there is broad support for evolutionary changes not consistent with EICA in defensive traits and competitive traits across invasive populations of these plant species.
Purpose
While distinct soil microbiomes and individual soil microbial taxa can alter particular plant traits under highly controlled conditions, little is known about the role of particular microbial ...taxa and microbial functions within complex soil microbial communities for mediating plant phenotypes or if the strength of microbial mediation of plant phenotype varies among plant species or plant phenotypic traits. Examining how the plant phenotype spectrum is influenced by the taxonomic and functional composition of complex soil microbial communities allows for a more accurate understanding of the biotic environmental drivers of plant phenotype.
Methods
Using rhizosphere soil collected from field sites, we conducted a microbiome transfer glasshouse experiment to test the hypothesis that the taxonomic and functional composition of different soil microbiomes would differentially shift growth, physiological or reproductive phenotypes of three
Solidago
species.
Results
We found that soil microbiome inoculations influenced
Solidago
growth traits more than physiological and reproductive traits. We found that root growth of one of the
Solidago
species was negatively correlated with 77% of the indicator bacterial and fungal taxa from one of the soil microbiome treatments.
Conclusions
Soil microbial mediation of plant phenotype varies by plant traits, is not universal across plant species, and can be associated with a small number of microbial taxa. This study illustrates that specific microbial taxa within a soil microbiome are associated with shifts in plant phenotype by pinpointing important individual microbial taxa from complex field soil microbial communities.
To examine whether young adult opioid misuse reflects a general tendency toward substance use and is influenced by general substance use risk or whether it is a different phenomenon from other drug ...use.
At ages 23 (2016) and 26 (2019), a panel of young adults (n = 3794 to 3833) in the United States self-reported their past-month substance use (opioid misuse, heavy drinking, cigarettes, cannabis) and substance-specific risk factors (perceptions of harm; approval of use; and use of each substance by friends and romantic partners). Structural equation models examined non-opioid and opioid-specific associations between latent risk and substance use factors.
Opioid misuse and opioid-specific risk factors shared significant variance with latent substance use and latent substance use risk, respectively, which were strongly associated. A statistically significant residual correlation between opioid-specific risk and opioid misuse remained.
Young adult opioid misuse reflects a general tendency toward substance use and is strongly predicted by risk for substance use. Opioid-specific risk factors play only a small independent role. Existing evidence-based substance use interventions may be effective in preventing opioid misuse among young adults.
•Young adult opioid misuse likely reflects a general tendency to use substances.•Risk for general substance use strongly predicts young adult opioid misuse.•Existing substance use prevention programs may be an efficient & effective strategy for combatting the opioid crisis in young adult populations.
Rare species are often considered inferior competitors due to occupancy of small ranges, specific habitats, and small local populations. However, the phylogenetic relatedness and rarity level (level ...1-7 and common) of interacting species in plant-plant interactions are not often considered when predicting the response of rare plants in a biotic context. We used a common garden of 25 species of Tasmanian Eucalyptus, to differentiate non-additive patterns in the biomass of rare versus common species when grown in mixtures varying in phylogenetic relatedness and rarity. We demonstrate that rare species maintain progressively positive non-additive responses in biomass when interacting with phylogenetically intermediate, less rare and common species. This trend is not reflected in common species that out-performed in monocultures compared to mixtures. These results offer predictability as to how rare species' productivity will respond within various plant-plant interactions. However, species-specific interactions, such as those involving E. globulus, yielded a 97% increase in biomass compared to other species-specific interaction outcomes. These results are important because they suggest that plant rarity may also be shaped by biotic interactions, in addition to the known environmental and population factors normally used to describe rarity. Rare species may utilize potentially facilitative interactions with phylogenetically intermediate and common species to escape the effects of limiting similarity. Biotically mediated increases in rare plant biomass may have subsequent effects on the competitive ability and geographic occurrence of rare species, allowing rare species to persist at low abundance across plant communities. Through the consideration of species rarity and evolutionary history, we can more accurately predict plant-plant interaction dynamics to preserve unique ecosystem functions and fundamentally challenge what it means to be "rare".
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