The unique morphological basis and parallel evolutionary history of personate flowers in .

Premise: Adaptive radiation in ecologically and morphologically diverse plant lineages presents an opportunity to investigate the rapid evolution of novel floral traits. While some types of floral traits, such as flower color, are well-characterized, other types of complex morphologies remain understudied. One example is occluded personate flowers, dorso-ventrally compressed flowers with obstructed floral passageways, which have evolved in multiple genera, but have only been characterized from snapdragon.

Ecological Diversification in an Adaptive Radiation of Plants: The Role of De Novo Mutation and Introgression.

Adaptive radiations are characterized by rapid ecological diversification and speciation events, leading to fuzzy species boundaries between ecologically differentiated species. Adaptive radiations are therefore key systems for understanding how species are formed and maintained, including the role of de novo mutations versus preexisting variation in ecological adaptation and the genome-wide consequences of hybridization events. For example, adaptive introgression, where beneficial alleles are transferred between lineages through hybridization, may fuel diversification in adaptive radiations and facilitate adaptation to new environments.

Ecological diversification in an adaptive radiation of plants: the role of de novo mutation and introgression.

Adaptive radiations are characterized by rapid ecological diversification and speciation events, leading to fuzzy species boundaries between ecologically differentiated species. Adaptive radiations are therefore key systems for understanding how species are formed and maintained, including the role of de novo mutations vs. pre-existing variation in ecological adaptation and the genome-wide consequences of hybridization events.

How the switch to hummingbird pollination has greatly contributed to our understanding of evolutionary processes.

The evolutionary switch to hummingbird pollination exemplifies complex adaptation, requiring evolutionary change in multiple component traits. Despite this complexity, diverse lineages have converged on hummingbird-adapted flowers on a relatively short evolutionary timescale. Here, I review how features of the genetic basis of adaptation contribute to this remarkable evolutionary lability.

A few essential genetic loci distinguish Penstemon species with flowers adapted to pollination by bees or hummingbirds.

In the formation of species, adaptation by natural selection generates distinct combinations of traits that function well together. The maintenance of adaptive trait combinations in the face of gene flow depends on the strength and nature of selection acting on the underlying genetic loci. Floral pollination syndromes exemplify the evolution of trait combinations adaptive for particular pollinators.

Opposing Patterns of Altitude-Driven Pollinator Turnover in the Tropical and Temperate Americas.

AbstractAbiotic factors (e.g., temperature, precipitation) vary markedly along elevational gradients and differentially affect major groups of pollinators.

Predictive Links between Petal Color and Pigment Quantities in Natural Penstemon Hybrids.

Flowers have evolved remarkable diversity in petal color, in large part due to pollinator-mediated selection. This diversity arises from specialized metabolic pathways that generate conspicuous pigments. Despite the clear link between flower color and floral pigment production, quantitative models inferring predictive relationships between pigmentation and reflectance spectra have not been reported.

Small genetic steps lead to mechanical isolation in hummingbird-pollinated gingers.

Interactions with pollinators are a potent source of natural selection driving the spectacular array of flowering plant diversity on Earth (Kay & Sargent, 2009; Van der Niet et al., 2014). Floral traits play a central role in this process: reliable and effective pollination by animal pollinators depends on complex floral features, including traits that determine pollinator attraction and reward, as well as the mechanics of pollen transfer.

Adaptation to lower latitudes and lower elevations precedes the evolution of hummingbird pollination in western North American Penstemon.

Premise: A switch in pollinator can occur when a plant lineage enters a new habitat where the ancestral pollinator is less common, and a novel pollinator is more common. Because pollinator communities vary according to environmental tolerances and availability of resources, there may be consistent associations between pollination mode and specific regions and habitats. Such associations can be studied in lineages that have experienced multiple pollinator transitions, representing evolutionary replicates.

Post-Traumatic Stress Symptoms in Caregivers and Children with Hydrocephalus.

Objective: Hydrocephalus is a disorder of cerebrospinal fluid dynamics, traditionally treated by placement of a ventricular shunt. Shunts are effective but imperfect as they fail in an unpredictable pattern, and the patient's well-being is dependent on adequate shunt function. The omnipresent threat of shunt failure along with the potential need for invasive investigations can be stressful for patients and caregivers.

From pollen dispersal to plant diversification: genetic consequences of pollination mode.

Pollinators influence patterns of plant speciation, and one intuitive hypothesis is that pollinators affect rates of plant diversification through their effects on pollen dispersal. By specifying mating events and pollen flow across the landscape, distinct types of pollinators may cause different opportunities for allopatric speciation. This pollen dispersal-dependent speciation hypothesis predicts that pollination mode has effects on the spatial context of mating events that scale up to impact population structure and rates of species formation.

Vitamin K Intake in Chronic Stroke: Implications for Dietary Recommendations.

Previous research has identified a possible association between vitamin K intake and cardiometabolic disease. This could mean that the assessment of vitamin K intake is a meaningful tool when monitoring individuals with preexisting cardiovascular disease. Sixty chronic stroke survivors (men and women, body mass index (BMI) 30.

Adaptation to hummingbird pollination is associated with reduced diversification in .

A striking characteristic of the Western North American flora is the repeated evolution of hummingbird pollination from insect-pollinated ancestors. This pattern has received extensive attention as an opportunity to study repeated trait evolution as well as potential constraints on evolutionary reversibility, with little attention focused on the impact of these transitions on species diversification rates. Yet traits conferring adaptation to divergent pollinators potentially impact speciation and extinction rates, because pollinators facilitate plant reproduction and specify mating patterns between flowering plants.

Individualized mating system estimation using genomic data.

The estimation of outcrossing rates in hermaphroditic species has been a major focus in the evolutionary study of reproductive strategies, and is also essential for plant breeding and conservation. Surprisingly, genomics has thus far minimally influenced outcrossing rate studies. In this article, we generalize a Bayesian inference method (BORICE) to accommodate genomic data from multiple subpopulations of a species.

Nectary size is a pollination syndrome trait in Penstemon.

Evolution of complex phenotypes depends on the adaptive importance of individual traits, and the developmental changes required to modify traits. Floral syndromes are complex adaptations to pollinators that include color, nectar, and shape variation. Hummingbird-adapted flowers have evolved a remarkable number of times from bee-adapted ancestors in Penstemon, and previous work demonstrates that color over shape better distinguishes bee from hummingbird syndromes.

SNP-skimming: A fast approach to map loci generating quantitative variation in natural populations.

Genome-wide association mapping (GWAS) is a method to estimate the contribution of segregating genetic loci to trait variation. A major challenge for applying GWAS to nonmodel species has been generating dense genome-wide markers that satisfy the key requirement that marker data are error-free. Here, we present an approach to map loci within natural populations using inexpensive shallow genome sequencing.

Selfing Can Facilitate Transitions between Pollination Syndromes.

Pollinator-mediated selection on plants can favor transitions to a new pollinator depending on the relative abundances and efficiencies of pollinators present in the community. A frequently observed example is the transition from bee pollination to hummingbird pollination. We present a population genetic model that examines whether the ability to inbreed can influence evolutionary change in traits that underlie pollinator attraction.

Examining Plant Physiological Responses to Climate Change through an Evolutionary Lens.

Integrating knowledge from physiological ecology, evolutionary biology, phylogenetics, and paleobiology provides novel insights into factors driving plant physiological responses to both past and future climate change.

Multiplexed shotgun genotyping resolves species relationships within the North American genus Penstemon.

Premise Of The Study: Evolutionary radiations provide opportunities to examine large-scale patterns in diversification and character evolution, yet are often recalcitrant to phylogenetic resolution due to rapid speciation events. The plant genus Penstemon has been difficult to resolve using Sanger sequence-based markers, leading to the hypothesis that it represents a recent North American radiation. The current study demonstrates the utility of multiplexed shotgun genotyping (MSG), a style of restriction site-associated DNA sequencing (RADseq), to infer phylogenetic relationships within a subset of species in this genus and provide insight into evolutionary patterns.

Accessibility, constraint, and repetition in adaptive floral evolution.

Adaptive phenotypic evolution is shaped by natural selection on multiple organismal traits as well as by genetic correlations among traits. Genetic correlations can arise through pleiotropy and can bias the production of phenotypic variation to certain combinations of traits. This phenomenon is referred to as developmental bias or constraint.

Ecological transition predictably associated with gene degeneration.

Gene degeneration or loss can significantly contribute to phenotypic diversification, but may generate genetic constraints on future evolutionary trajectories, potentially restricting phenotypic reversal. Such constraints may manifest as directional evolutionary trends when parallel phenotypic shifts consistently involve gene degeneration or loss. Here, we demonstrate that widespread parallel evolution in Penstemon from blue to red flowers predictably involves the functional inactivation and degeneration of the enzyme flavonoid 3',5'-hydroxylase (F3'5'H), an anthocyanin pathway enzyme required for the production of blue floral pigments.