"Scientists are People too": Biology Students Relate More to Scientists When They are Humanized in Course Materials.

Featuring scientists in classroom materials provides opportunities for students to relate to scientists as role models and see themselves in science. However, it is unclear what information students find most relatable when encountering scientists throughout their education. In this study, we manipulated the amount and type of information provided about scientists featured in biology courses.

A global assessment of plant-mite mutualism and its ecological drivers.

Mutualisms are mediated by adaptive traits of interacting organisms and play a central role in the ecology and evolution of species. Thousands of plant species possess tiny structures called "domatia" that house mites which protect plants from pests, yet these traits remain woefully understudied. Here, we release a worldwide database of species with mite domatia and provide an evaluation of the phylogenetic and geographic distribution of this mutualistic trait.

Small, but mitey: investigating the molecular genetic basis for mite domatia development and intraspecific variation in Vitis riparia using transcriptomics.

Here, we investigated the molecular genetic basis of mite domatia, structures on the underside of leaves that house mutualistic mites, and intraspecific variation in domatia size in Vitis riparia (riverbank grape). Domatia and leaf traits were measured, and the transcriptomes of mite domatia from two genotypes of V. riparia with distinct domatia sizes were sequenced to investigate the molecular genetic pathways that regulate domatia development and intraspecific variation in domatia traits.

Diversity and development of domatia: Symbiotic plant structures to host mutualistic ants or mites.

Across the tree of life, specialized structures that offer nesting sites to ants or mites - known as domatia - have evolved independently hundreds of times, facilitating ecologically important defence and/or nutritional mutualisms. Domatia show remarkable diversity in morphology and developmental origin. Here we review the morpho-anatomical diversity of domatia, aiming to unveil the primary mechanisms governing their development.

Evolutionary signatures of a trade-off in direct and indirect defenses across the wild grape genus, Vitis.

Evolutionary correlations between chemical defense and protection by mutualist bodyguards have been long predicted, but tests of these patterns remain rare. We use a phylogenetic framework to test for evolutionary correlations indicative of trade-offs or synergisms between direct defense in the form of plant secondary metabolism and indirect defense in the form of leaf domatia, across 33 species in the wild grape genus, Vitis. We also performed a bioassay with a generalist herbivore to associate our chemical phenotypes with herbivore palatability.

Macroevolution of protective coloration across caterpillars reflects relationships with host plants.

A critical function of animal coloration is avoiding attack, either by warning predators or reducing detectability. Evolution of these divergent strategies may depend on prey palatability and apparency to predators: conspicuous coloration may be favoured if species are distasteful, or habitats make hiding difficult; by contrast, camouflage may be effective if prey lack defences or environments are visually complex. For insect herbivores, host plants provide both chemical defence and the background against which they are detected or obscured; thus, plant traits may be key to coloration in these foundational terrestrial organisms.

Modeling the Evolution of Rates of Continuous Trait Evolution.

Rates of phenotypic evolution vary markedly across the tree of life, from the accelerated evolution apparent in adaptive radiations to the remarkable evolutionary stasis exhibited by so-called "living fossils." Such rate variation has important consequences for large-scale evolutionary dynamics, generating vast disparities in phenotypic diversity across space, time, and taxa. Despite this, most methods for estimating trait evolution rates assume rates vary deterministically with respect to some variable of interest or change infrequently during a clade's history.

Six Principles for Embracing Gender and Sexual Diversity in Postsecondary Biology Classrooms.

Sexual and gender minorities face considerable inequities in society, including in science. In biology, course content provides opportunities to challenge harmful preconceptions about what is "natural" while avoiding the notion that anything found in nature is inherently good (the appeal-to-nature fallacy). We provide six principles for instructors to teach sex- and gender-related topics in postsecondary biology in a more inclusive and accurate manner: highlighting biological diversity early, presenting the social and historical context of science, using inclusive language, teaching the iterative process of science, presenting students with a diversity of role models, and developing a classroom culture of respect and inclusion.

Genome-Wide Association Study Reveals Genomic Region Associated with Mite-Recruitment Phenotypes in the Domesticated Grapevine ().

Indirect defenses are plant phenotypes that reduce damage by attracting natural enemies of plant pests and pathogens to leaves. Despite their economic and ecological importance, few studies have investigated the genetic underpinnings of indirect defense phenotypes. Here, we present a genome-wide association study of five phenotypes previously determined to increase populations of beneficial (fungivorous and predacious) mites on grape leaves (genus ): leaf bristles, leaf hairs, and the size, density, and depth of leaf domatia.

Generalising indirect defence and resistance of plants.

Indirect defence, the adaptive top-down control of herbivores by plant traits that enhance predation, is a central component of plant-herbivore interactions. However, the scope of interactions that comprise indirect defence and associated ecological and evolutionary processes has not been clearly defined. We argue that the range of plant traits that mediate indirect defence is much greater than previously thought, and we further organise major concepts surrounding their ecological functioning.

Toxicity of the spiny thick-foot Pachypodium.

Premise Of The Study: Pachypodium (Apocynaceae) is a genus of iconic stem-succulent and poisonous plants endemic to Madagascar and southern Africa. We tested hypotheses about the mode of action and macroevolution of toxicity in this group. We further hypothesized that while monarch butterflies are highly resistant to cardenolide toxins (a type of cardiac glycoside) from American Asclepias, they may be negatively affected by Pachypodium defenses, which evolved independently.

The evolution of floral signals in relation to range overlap in a clade of California Jewelflowers (Streptanthus s.l.).

Because of their function as reproductive signals in plants, floral traits experience distinct selective pressures related to their role in speciation, reinforcement, and prolonged coexistence with close relatives. However, few studies have investigated whether population-level processes translate into detectable signatures at the macroevolutionary scale. Here, we ask whether patterns of floral trait evolution and range overlap across a clade of California Jewelflowers reflect processes hypothesized to shape floral signal differentiation at the population level.

Pattern and Process in the Comparative Study of Convergent Evolution.

Understanding processes that have shaped broad-scale biodiversity patterns is a fundamental goal in evolutionary biology. The development of phylogenetic comparative methods has yielded a tool kit for analyzing contemporary patterns by explicitly modeling processes of change in the past, providing neontologists tools for asking questions previously accessible only for select taxa via the fossil record or laboratory experimentation. The comparative approach, however, differs operationally from alternative approaches to studying convergence in that, for studies of only extant species, convergence must be inferred using evolutionary process models rather than being directly measured.

Evolution in a Community Context: On Integrating Ecological Interactions and Macroevolution.

Despite a conceptual understanding that evolution and species interactions are inextricably linked, it remains challenging to study ecological and evolutionary dynamics together over long temporal scales. In this review, we argue that, despite inherent challenges associated with reconstructing historical processes, the interplay of ecology and evolution is central to our understanding of macroevolution and community coexistence, and cannot be safely ignored in community and comparative phylogenetic studies. We highlight new research avenues that foster greater consideration of both ecological and evolutionary dynamics as processes that occur along branches of phylogenetic trees.

Macroevolution of perfume signalling in orchid bees.

Theory predicts that both stabilising selection and diversifying selection jointly contribute to the evolution of sexual signalling traits by (1) maintaining the integrity of communication signals within species and (2) promoting the diversification of traits among lineages. However, for many important signalling traits, little is known about whether these dynamics translate into predictable macroevolutionary signatures. Here, we test for macroevolutionary patterns consistent with sexual signalling theory in the perfume signals of neotropical orchid bees, a group well studied for their chemical sexual communication.

Foliar nectar enhances plant-mite mutualisms: the effect of leaf sugar on the control of powdery mildew by domatia-inhabiting mites.

Background And Aims: Mite domatia are small structures on the underside of plant leaves that provide homes for predacious or fungivorous mites. In turn, mites inhabiting domatia defend the plant by consuming leaf herbivores and pathogens, which can result in a domatia-mediated, plant-mite defence mutualism. Several recent studies have suggested that plants receive enhanced benefits when they provide a foliar food source, such as sugars secreted from extrafloral nectaries, to mite mutualists alongside mite domatia.

Olfactory specialization for perfume collection in male orchid bees.

Insects rely on the olfactory system to detect a vast diversity of airborne molecules in their environment. Highly sensitive olfactory tuning is expected to evolve when detection of a particular chemical with great precision is required in the context of foraging and/or finding mates. Male neotropical orchid bees (Euglossini) collect odoriferous substances from multiple sources, store them in specialized tibial pouches and later expose them at display sites, presumably as mating signals to females.

Cuticular Hydrocarbons as Potential Close Range Recognition Cues in Orchid Bees.

Male Neotropical orchid bees collect volatile chemicals from their environment and compose species-specific volatile signals, which are subsequently exposed during courtship display. These perfumes are hypothesized to serve as attractants and may play a role in female mate choice. Here, we investigated the potential of cuticular hydrocarbons as additional recognition cues.

On the study of plant defence and herbivory using comparative approaches: how important are secondary plant compounds.

Species comparisons are a cornerstone of biology and there is a long tradition of using the comparative framework to study the ecology and evolution of plant defensive traits. Early comparative studies led to the hypothesis that plant chemistry plays a central role in plant defence, and the evolution of plant secondary chemistry in response to insect herbivory remains a classic example of coevolution. However, recent comparative work has disagreed with this paradigm, reporting little connection between plant secondary chemicals and herbivory across distantly related plant taxa.

Defense mutualisms enhance plant diversification.

The ability of plants to form mutualistic relationships with animal defenders has long been suspected to influence their evolutionary success, both by decreasing extinction risk and by increasing opportunity for speciation through an expanded realized niche. Nonetheless, the hypothesis that defense mutualisms consistently enhance plant diversification across lineages has not been well tested due to a lack of phenotypic and phylogenetic information. Using a global analysis, we show that the >100 vascular plant families in which species have evolved extrafloral nectaries (EFNs), sugar-secreting organs that recruit arthropod mutualists, have twofold higher diversification rates than families that lack species with EFNs.

The phylogenetic distribution of extrafloral nectaries in plants.

Background And Aims: Understanding the evolutionary patterns of ecologically relevant traits is a central goal in plant biology. However, for most important traits, we lack the comprehensive understanding of their taxonomic distribution needed to evaluate their evolutionary mode and tempo across the tree of life. Here we evaluate the broad phylogenetic patterns of a common plant-defence trait found across vascular plants: extrafloral nectaries (EFNs), plant glands that secrete nectar and are located outside the flower.

Phylogenetic and experimental tests of interactions among mutualistic plant defense traits in Viburnum (adoxaceae).

Plant traits that mediate mutualistic interactions are widespread, yet few studies have linked their macroevolutionary patterns with the ecological interactions they mediate. Here we merged phylogenetic and experimental approaches to investigate the evolution of two common mutualistic plant traits, extrafloral nectaries (EFNs) and leaf domatia. By using the flowering plant clade Viburnum, we tested whether macroevolutionary patterns support adaptive hypotheses and conducted field surveys and manipulative experiments to examine whether ecological interactions are concordant with evolutionary predictions.

Phylogeny, ecology, and the coupling of comparative and experimental approaches.

Recent progress in the development of phylogenetic methods and access to molecular phylogenies has made comparative biology more popular than ever before. However, determining cause and effect in phylogenetic comparative studies is inherently difficult without experimentation and evolutionary replication. Here, we provide a roadmap for linking comparative phylogenetic patterns with ecological experiments to test causal hypotheses across ecological and evolutionary scales.