Prevalence and intensity of avian malaria in a quail hybrid zone.

Hybrid zones have been described as natural laboratories by researchers who study speciation and the various mechanisms that may affect gene flow. The evolutionary consequences of hybridization depend not only on reproductive compatibility between sympatric species, but also on factors like vulnerability to each other's predators and parasites. We examined infection patterns of the blood parasite , a causative agent of avian malaria, at a site in the contact zone between California quail () and Gambel's quail ().

An index for measuring functional extension and evenness in trait space.

Most existing functional diversity indices focus on a single facet of functional diversity. Although these indices are useful for quantifying specific aspects of functional diversity, they often present some conceptual or practical limitations in estimating functional diversity. Here, we present a new functional extension and evenness (FEE) index that encompasses two important aspects of functional diversity.

Identification of novel bacterial biomarkers to detect bird scavenging by invasive rats.

Rapid advances in genomic tools for use in ecological contexts and non-model systems allow unprecedented insight into interactions that occur beyond direct observation. We developed an approach that couples microbial forensics with molecular dietary analysis to identify species interactions and scavenging by invasive rats on native and introduced birds in Hawaii. First, we characterized bacterial signatures of bird carcass decay by conducting 16S rRNA high-throughput sequencing on chicken () tissues collected over an 11-day decomposition study in natural Hawaiian habitats.

Origin and evolution of a gibberellin-deactivating enzyme GAMT.

Gibberellins (GAs) are a major class of plant hormones that regulates diverse developmental programs. Both acquiring abilities to synthesize GAs and evolving divergent GA receptors have been demonstrated to play critical roles in the evolution of land plants. In contrast, little is understood regarding the role of GA-inactivating mechanisms in plant evolution.

Jasmonate induced alternative splicing responses in .

Unlabelled: Jasmonate is an essential phytohormone regulating plant growth, development, and defense. Alternative splicing (AS) in jasmonate ZIM-domain (JAZ) repressors is well-characterized and plays an important role in jasmonate signaling regulation. However, it is unknown whether other genes in the jasmonate signaling pathway are regulated by AS.

Unraveling the role of the enigmatic MatK maturase in chloroplast group IIA intron excision.

Maturases are prokaryotic enzymes that aid self-excision of introns in precursor RNAs and have evolutionary ties to the nuclear spliceosome. Both the mitochondria and chloroplast, due to their prokaryotic origin, encode a single intron maturase, MatR for the mitochondria and MatK for the chloroplast. MatK is proposed to aid excision of seven different chloroplast group IIA introns that reside within precursor RNAs for essential elements of chloroplast function.

The genetics of phenotypic plasticity. XVII. Response to climate change.

The world is changing at a rapid rate, threatening extinction for a large part of the world's biota. One potential response to those altered conditions is to evolve so as to be able to persist in place. Such evolution includes not just traits themselves, but also the phenotypic plasticity of those traits.

Foraging ecology drives social information reliance in an avian eavesdropping community.

Vertebrates obtain social information about predation risk by eavesdropping on the alarm calls of sympatric species. In the Holarctic, birds in the family Paridae function as sentinel species; however, factors shaping eavesdroppers' reliance on their alarm calls are unknown. We compared three hypothesized drivers of eavesdropper reliance: (a) foraging ecology, (b) degree of sociality, and (c) call relevance (caller-to-eavesdropper body-size difference).

Effects of taxon sampling and tree reconstruction methods on phylodiversity metrics.

The amount and patterns of phylodiversity in a community are often used to draw inferences about the local and historical factors affecting community assembly and can be used to prioritize communities and locations for conservation. Because measures of phylodiversity are based on the topology and branch lengths of phylogenetic trees, which are affected by the number and diversity of taxa in the tree, these analyses may be sensitive to changes in taxon sampling and tree reconstruction methods.To investigate the effects of taxon sampling and tree reconstruction methods on measures of phylodiversity, we investigated the community phylogenetics of the Ordway-Swisher Biological Station (Florida), which is home to over 600 species of vascular plants.

Host species, and not environment, predicts variation in blood parasite prevalence, distribution, and diversity along a humidity gradient in northern South America.

Environmental factors strongly influence the ecology and evolution of vector-borne infectious diseases. However, our understanding of the influence of climatic variation on host-parasite interactions in tropical systems is rudimentary. We studied five species of birds and their haemosporidian parasites ( and ) at 16 sampling sites to understand how environmental heterogeneity influences patterns of parasite prevalence, distribution, and diversity across a marked gradient in water availability in northern South America.

Effects of overexpression of jasmonic acid biosynthesis genes on nicotine accumulation in tobacco.

Nicotine is naturally synthesized in tobacco roots and accumulates in leaves as a defense compound against herbivory attack. Nicotine biosynthesis pathway has been extensively studied with major genes and enzymes being isolated and functionally characterized. However, the molecular regulation of nicotine synthesis has not been fully understood.

Broadening the voice of science: Promoting scientific communication in the undergraduate classroom.

Effective and accurate communication of scientific findings is essential. Unfortunately, scientists are not always well trained in how to best communicate their results with other scientists nor do all appreciate the importance of speaking with the public. Here, we provide an example of how the development of oral communication skills can be integrated with research experiences at the undergraduate level.

The genetics of phenotypic plasticity. XV. Genetic assimilation, the Baldwin effect, and evolutionary rescue.

We used an individual-based simulation model to examine the role of phenotypic plasticity on persistence and adaptation to two patterns of environmental variation, a single, abrupt step change and continual, linear change. Our model tested the assumptions and predictions of the theory of genetic assimilation, explored the evolutionary dynamics of the Baldwin effect, and provided expectations for the evolutionary response to climate change. We found that genetic assimilation as originally postulated is not likely to occur because the replacement of plasticity by fixed genetic effects takes much longer than the environment is likely to remain stable.

Population structure of a widespread bat () in an island system.

Dispersal is a driving factor in the creation and maintenance of biodiversity, yet little is known about the effects of habitat variation and geography on dispersal and population connectivity in most mammalian groups. Bats of the family Molossidae are fast-flying mammals thought to have potentially high dispersal ability, and recent studies have indicated gene flow across hundreds of kilometers in continental North American populations of the Brazilian free-tailed bat, . We examined the population genetics, phylogeography, and morphology of this species in Florida and across islands of The Bahamas, which are part of an island archipelago in the West Indies.

The influence of herbivory and weather on the vital rates of two closely related cactus species.

Herbivory has long been recognized as a significant driver of plant population dynamics, yet its effects along environmental gradients are unclear. Understanding how weather modulates plant-insect interactions can be particularly important for predicting the consequences of exotic insect invasions, and an explicit consideration of weather may help explain why the impact can vary greatly across space and time. We surveyed two native prickly pear cactus species (genus ) in the Florida panhandle, USA, and their specialist insect herbivores (the invasive South American cactus moth, , and three native insect species) for five years across six sites.

The impact of parasitism on resource allocation in a fungal host: the case of and its mycovirus, Cryphonectria Hypovirus 1.

Parasites are known to profoundly affect resource allocation in their host. In order to investigate the effects of Cryphonectria Hypovirus 1 (CHV1) on the life-history traits of its fungal host an infection matrix was completed with the cross-infection of six fungal isolates by six different viruses. Mycelial growth, asexual sporulation, and spore size were measured in the 36 combinations, for which horizontal and vertical transmission of the viruses was also assessed.

Dispersal corridors for plant species in the Poyang Lake Basin of southeast China identified by integration of phylogeographic and geospatial data.

Measuring the dispersal of wildlife through landscapes is notoriously difficult. Recently, the categorical least cost path algorithm that integrates population genetic data with species distribution models has been applied to reveal population connectivity. In this study, we use this method to identify the possible dispersal corridors of five plant species (, , , , ) in the Poyang Lake Basin (PLB, largely coinciding with Jiangxi Province), China, in the late Quaternary.

Semi-supervised determination of pseudocryptic morphotypes using observer-free characterizations of anatomical alignment and shape.

Accurate, quantitative characterization of complex shapes is recognized as a key methodological challenge in biology. Recent development of automated three-dimensional geometric morphometric protocols (auto3dgm) provides a promising set of tools to help address this challenge. While auto3dgm has been shown to be useful in characterizing variation across clades of morphologically very distinct mammals, it has not been adequately tested in more problematic cases where pseudolandmark placement error potentially confounds interpretation of true shape variation.

RNA editing by the host ADAR system affects the molecular evolution of the Zika virus.

Zika virus (ZIKV) is a mosquito-transmitted flavivirus, linked to microcephaly and fetal death in humans. Here, we investigate whether host-mediated RNA editing of adenosines (ADAR) plays a role in the molecular evolution of ZIKV. Using complete coding sequences for the ZIKV polyprotein, we show that potential ADAR substitutions are underrepresented at the ADAR-resistant GA dinucleotides of both the positive and negative strands, that these changes are spatially and temporally clustered (as expected of ADAR editing) for three branches of the viral phylogeny, and that ADAR mutagenesis can be linked to its codon usage.

The evolutionary trade-off between stem cell niche size, aging, and tumorigenesis.

Many epithelial tissues within multicellular organisms are continually replenished by small independent populations of stem cells largely responsible for maintaining tissue homeostasis. These continually dividing populations are subject to mutations that can lead to tumorigenesis but also contribute to aging. Mutations accumulate in stem cell niches and change the rate of cell division and differentiation; the pace of this process and the fate of specific mutations depend strongly on niche population size.

The implications of small stem cell niche sizes and the distribution of fitness effects of new mutations in aging and tumorigenesis.

Somatic tissue evolves over a vertebrate's lifetime due to the accumulation of mutations in stem cell populations. Mutations may alter cellular fitness and contribute to tumorigenesis or aging. The distribution of mutational effects within somatic cells is not known.