Gynodioecy and Biotic Interactions: Plant Traits, Insect Preferences, and Population-Level Consequences

In species with distinct sexes, differences between the sexes often affect interspecific interactions. In gynodioecious flowering plants, where individuals are female or hermaphrodite, both pollinators and herbivores tend to prefer hermaphrodites. Because pollinators and herbivores affect plant fitness, their preferences have consequences for plant mating patterns, natural selection on mating-related traits, and plant breeding system evolution. Being sessile, the spatial arrangement of females and hermaphrodites in gynodioecious plant populations alters conspecific density and sex ratio locally, which can also have important fitness effects. My dissertation combines observational studies in natural Silene vulgaris populations and simulation modeling to address questions about how females and hermaphrodites experience intraspecific and interspecific interactions, with consequences for reproductive success, selection on traits, and population sex ratio evolution. Chapter 1 is an introduction. Chapter 2 addresses effects of plant sex and floral and vegetative traits on a recently described interaction between S. vulgaris and Hadena ectypa, a moth that pollinates plants but also deposits eggs in flowers with developing larvae feeding on plant reproductive tissues. Moth oviposition was hermaphrodite-biased and associated with plants having deeper flowers and more stems. However, moth oviposition had limited fitness consequences for host plants, as plants that received moth eggs lost relatively few fruits to predation, receiving eggs did not affect fruit production at the plant level, and oviposition was not associated with enhanced pollination. Chapter 3 demonstrates scale-dependent effects of conspecific density and sex ratio on reproduction and phenotypic selection in S. vulgaris. Fine scale density variation had opposite effects on reproduction in females and hermaphrodites, both sexes experienced enhanced reproductive success with increasing hermaphrodite frequency at high densities, and females and hermaphrodites experienced different effects of density on phenotypic selection. Chapter 4 uses simulation models to assess how pollinator sex bias intensity affects female maintenance and sex ratio evolution in gynodioecious plant populations, finding that even small preferences for hermaphrodites can lead to the loss of females from populations. Taken together, my work sheds new light on the patterns and processes that affect reproduction, selection on floral and vegetative traits, and the maintenance of females in gynodioecious plant populations

Sex-biased oviposition by a nursery pollinator on a gynodioecious host plant: Implications for breeding system evolution and evolution of mutualism

Dioecy, a breeding system where individual plants are exclusively male or female, has evolved repeatedly. Extensive theory describes when dioecy should arise from hermaphroditism, frequently through gynodioecy, where females and hermaphrodites coexist, and when gynodioecy should be stable. Both pollinators and herbivores often prefer the pollen-bearing sex, with sex-specific fitness effects that can affect breeding system evolution. Nursery pollination, where adult insects pollinate flowers but their larvae feed on plant reproductive tissues, is a model for understanding mutualism evolution but could also yield insights into plant breeding system evolution. We studied a recently established nursery pollination interaction between native Hadena ectypa moths and introduced gynodioecious Silene vulgaris plants in North America to assess whether oviposition was biased toward females or hermaphrodites, which traits were associated with oviposition, and the effect of oviposition on host plant fitness. Oviposition was hermaphrodite-biased and associated with deeper flowers and more stems. Sexual dimorphism in flower depth, a trait also associated with oviposition on the native host plant (Silene stellata), explained the hermaphrodite bias. Egg-receiving plants experienced more fruit predation than plants that received no eggs, but relatively few fruits were lost, and egg receipt did not significantly alter total fruit production at the plant level. Oviposition did not enhance pollination; egg-receiving flowers usually failed to expand and produce seeds. Together, our results suggest that H. ectypa oviposition does not exert a large fitness cost on host plants, sex-biased interactions can emerge from preferences developed on a hermaphroditic host species, and new nursery pollination interactions can arise as negative or neutral rather than as mutualistic for the plant

Meta-research: the growth of acronyms in the scientific literature

Some acronyms are useful and are widely understood, but many of the acronyms used in scientific papers hinder understanding and contribute to the increasing fragmentation of science. Here we report the results of an analysis of more than 24 million article titles and 18 million article abstracts published between 1950 and 2019. There was at least one acronym in 19% of the titles and 73% of the abstracts. Acronym use has also increased over time, but the re-use of acronyms has declined. We found that from more than one million unique acronyms in our data, just over 2,000 (0.2%) were used regularly, and most acronyms (79%) appeared fewer than 10 times. Acronyms are not the biggest current problem in science communication, but reducing their use is a simple change that would help readers and potentially increase the value of science.Adrian Barnett and Zoe Doubleda

Automating Hyperspectral Data for Rapid Response in Volcanic Emergencies

In a volcanic emergency, time is of the essence. It is vital to quantify eruption parameters (thermal emission, effusion rate, location of activity) and distribute this information as quickly as possible to decision-makers in order to enable effective evaluation of eruption-related risk and hazard. The goal of this work was to automate and streamline processing of spacecraft hyperspectral data, automate product generation, and automate distribution of products. Visible and Short-Wave Infrared Images of volcanic eruption in Iceland in May 2010." class="caption" align="right">The software rapidly processes hyperspectral data, correcting for incident sunlight where necessary, and atmospheric transmission; detects thermally anomalous pixels; fits data with model black-body thermal emission spectra to determine radiant flux; calculates atmospheric convection thermal removal; and then calculates total heat loss. From these results, an estimation of effusion rate is made. Maps are generated of thermal emission and location (see figure). Products are posted online, and relevant parties notified. Effusion rate data are added to historical record and plotted to identify spikes in activity for persistently active eruptions. The entire process from start to end is autonomous. Future spacecraft, especially those in deep space, can react to detection of transient processes without the need to communicate with Earth, thus increasing science return. Terrestrially, this removes the need for human intervention

Change-Based Satellite Monitoring Using Broad Coverage and Targetable Sensing

A generic software framework analyzes data from broad coverage sweeps or general larger areas of interest. Change detection methods are used to extract subsets of directed swath areas that intersect areas of change. These areas are prioritized and allocated to targetable assets. This method is deployed in an automatic fashion, and has operated without human monitoring or intervention for sustained periods of time (months)

Timing of Case‐Based Discussions and Educational Outcomes for Dental Students

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/153714/1/jddjde018056.pd

Eight habitats, 38 threats and 55 experts: Assessing ecological risk in a multi-use marine region

Published: May 10, 2017Identifying the relative risk human activities pose to a habitat, and the ecosystem services they provide, can guide management prioritisation and resource allocation. Using a combination of expert elicitation to assess the probable effect of a threat and existing data to assess the level of threat exposure, we conducted a risk assessment for 38 human-mediated threats to eight marine habitats (totalling 304 threat-habitat combinations) in Spencer Gulf, Australia. We developed a score-based survey to collate expert opinion and assess the relative effect of each threat to each habitat, as well as a novel and independent measure of knowledge-based uncertainty. Fifty-five experts representing multiple sectors and institutions participated in the study, with 6 to 15 survey responses per habitat (n = 81 surveys). We identified key threats specific to each habitat; overall, climate change threats received the highest risk rankings, with nutrient discharge identified as a key local-scale stressor. Invasive species and most fishing-related threats, which are commonly identified as major threats to the marine environment, were ranked as low-tier threats to Spencer Gulf, emphasising the importance of regionally-relevant assessments. Further, we identified critical knowledge gaps and quantified uncertainty scores for each risk. Our approach will facilitate prioritisation of resource allocation in a region of increasing social, economic and environmental importance, and can be applied to marine regions where empirical data are lacking.Zoë A. Doubleday, Alice R. Jones, Marty R. Deveney, Tim M. Ward, Bronwyn M. Gillander

Social Constructivism and Case-Writing for an Integrated Curriculum

Case-writing within an integrated, systems-based health professions education curriculum presents many unique challenges. Specifically, case-writing in this context must consider integration of multidisciplinary learning objectives and synthesis of biomedical and clinical sciences. Establishing an effective process for content integration and determining who should be involved in the case-writing process can be a daunting task and this specific context requires a new model for effective casewriting. This paper provides a model for the cycle of case development, implementation, evaluation and modification in an integrated, systems-based health professions curriculum. We highlight how this collaborative case-writing model parallels the social constructivist approach promoted by the problem-based learning process in which our students engage