The nature of the last universal common ancestor and its impact on the early Earth system.

The nature of the last universal common ancestor (LUCA), its age and its impact on the Earth system have been the subject of vigorous debate across diverse disciplines, often based on disparate data and methods. Age estimates for LUCA are usually based on the fossil record, varying with every reinterpretation. The nature of LUCA's metabolism has proven equally contentious, with some attributing all core metabolisms to LUCA, whereas others reconstruct a simpler life form dependent on geochemistry.

Plant evolution: Streptophyte multicellularity, ecology, and the acclimatisation of plants to life on land.

Land plants are celebrated as one of the three great instances of complex multicellularity, but new phylogenomic and phenotypic analyses are revealing deep evolutionary roots of multicellularity among algal relatives, prompting questions about the causal basis of this major evolutionary transition.

Hagfish genome elucidates vertebrate whole-genome duplication events and their evolutionary consequences.

Polyploidy or whole-genome duplication (WGD) is a major event that drastically reshapes genome architecture and is often assumed to be causally associated with organismal innovations and radiations. The 2R hypothesis suggests that two WGD events (1R and 2R) occurred during early vertebrate evolution. However, the timing of the 2R event relative to the divergence of gnathostomes (jawed vertebrates) and cyclostomes (jawless hagfishes and lampreys) is unresolved and whether these WGD events underlie vertebrate phenotypic diversification remains elusive.

Discovery and validation of genes driving drug-intake and related behavioral traits in mice.

Substance use disorders are heritable disorders characterized by compulsive drug use, the biological mechanisms for which remain largely unknown. Genetic correlations reveal that predisposing drug-naïve phenotypes, including anxiety, depression, novelty preference and sensation seeking, are predictive of drug-use phenotypes, thereby implicating shared genetic mechanisms. High-throughput behavioral screening in knockout (KO) mice allows efficient discovery of the function of genes.

Evolution of phenotypic disparity in the plant kingdom.

The plant kingdom exhibits diverse bodyplans, from single-celled algae to complex multicellular land plants, but it is unclear how this phenotypic disparity was achieved. Here we show that the living divisions comprise discrete clusters within morphospace, separated largely by reproductive innovations, the extinction of evolutionary intermediates and lineage-specific evolution. Phenotypic complexity correlates not with disparity but with ploidy history, reflecting the role of genome duplication in plant macroevolution.

Genome evolution in plants and the origins of innovation.

Plant evolution has been characterised by a series of major novelties in their vegetative and reproductive traits that have led to greater complexity. Underpinning this diversification has been the evolution of the genome. When viewed at the scale of the plant kingdom, plant genome evolution has been punctuated by conspicuous instances of gene and whole-genome duplication, horizontal gene transfer and extensive gene loss.

DISCOVERY AND VALIDATION OF GENES DRIVING DRUG-INTAKE AND RELATED BEHAVIORAL TRAITS IN MICE.

Substance use disorders (SUDs) are heritable disorders characterized by compulsive drug use, but the biological mechanisms driving addiction remain largely unknown. Genetic correlations reveal that predisposing drug-naïve phenotypes, including anxiety, depression, novelty preference, and sensation seeking, are predictive of drug-use phenotypes, implicating shared genetic mechanisms. Because of this relationship, high-throughput behavioral screening of predictive phenotypes in knockout (KO) mice allows efficient discovery of genes likely to be involved in drug use.

Constraining Whole-Genome Duplication Events in Geological Time.

The timing of whole-genome duplication (WGD) events is crucial to understanding their role in evolution and underpins many hypotheses linking WGD to increased diversity and complexity. As such, means of estimating the timing of the WGD events relative to their macroevolutionary outcomes are of considerable importance. Molecular clock methods facilitate direct estimation of the absolute timing of WGD events, integrating information on the rate of sequence evolution between species while accommodating the uncertainty inherent to the fossil record.

Divergent evolutionary trajectories of bryophytes and tracheophytes from a complex common ancestor of land plants.

The origin of plants and their colonization of land fundamentally transformed the terrestrial environment. Here we elucidate the basis of this formative episode in Earth history through patterns of lineage, gene and genome evolution. We use new fossil calibrations, a relative clade age calibration (informed by horizontal gene transfer) and new phylogenomic methods for mapping gene family origins.

The origin and evolution of stomata.

The acquisition of stomata is one of the key innovations that led to the colonisation of the terrestrial environment by the earliest land plants. However, our understanding of the origin, evolution and the ancestral function of stomata is incomplete. Phylogenomic analyses indicate that, firstly, stomata are ancient structures, present in the common ancestor of land plants, prior to the divergence of bryophytes and tracheophytes and, secondly, there has been reductive stomatal evolution, especially in the bryophytes (with complete loss in the liverworts).

An estimate of the deepest branches of the tree of life from ancient vertically evolving genes.

Core gene phylogenies provide a window into early evolution, but different gene sets and analytical methods have yielded substantially different views of the tree of life. Trees inferred from a small set of universal core genes have typically supported a long branch separating the archaeal and bacterial domains. By contrast, recent analyses of a broader set of non-ribosomal genes have suggested that Archaea may be less divergent from Bacteria, and that estimates of inter-domain distance are inflated due to accelerated evolution of ribosomal proteins along the inter-domain branch.

Origin of horsetails and the role of whole-genome duplication in plant macroevolution.

Whole-genome duplication (WGD) has occurred commonly in land plant evolution and it is often invoked as a causal agent in diversification, phenotypic and developmental innovation, as well as conferring extinction resistance. The ancient and iconic lineage of is no exception, where WGD has been inferred to have occurred prior to the Cretaceous-Palaeogene (K-Pg) boundary, coincident with WGD events in angiosperms. In the absence of high species diversity, WGD in is interpreted to have facilitated the long-term survival of the lineage.

Evolution of metazoan morphological disparity.

The animal kingdom exhibits a great diversity of organismal form (i.e., disparity).

Integrated genomic and fossil evidence illuminates life's early evolution and eukaryote origin.

Establishing a unified timescale for the early evolution of Earth and life is challenging and mired in controversy because of the paucity of fossil evidence, the difficulty of interpreting it and dispute over the deepest branching relationships in the tree of life. Surprisingly, it remains perhaps the only episode in the history of life where literal interpretations of the fossil record hold sway, revised with every new discovery and reinterpretation. We derive a timescale of life, combining a reappraisal of the fossil material with new molecular clock analyses.

Whole-Genome Duplication and Plant Macroevolution.

Whole-genome duplication (WGD) is characteristic of almost all fundamental lineages of land plants. Unfortunately, the timings of WGD events are loosely constrained and hypotheses of evolutionary consequence are poorly formulated, making them difficult to test. Using examples from across the plant kingdom, we show that estimates of timing can be improved through the application of molecular clock methodology to multigene datasets.

The timescale of early land plant evolution.

Establishing the timescale of early land plant evolution is essential for testing hypotheses on the coevolution of land plants and Earth's System. The sparseness of early land plant megafossils and stratigraphic controls on their distribution make the fossil record an unreliable guide, leaving only the molecular clock. However, the application of molecular clock methodology is challenged by the current impasse in attempts to resolve the evolutionary relationships among the living bryophytes and tracheophytes.

Constraining the timing of whole genome duplication in plant evolutionary history.

Whole genome duplication (WGD) has occurred in many lineages within the tree of life and is invariably invoked as causal to evolutionary innovation, increased diversity, and extinction resistance. Testing such hypotheses is problematic, not least since the timing of WGD events has proven hard to constrain. Here we show that WGD events can be dated through molecular clock analysis of concatenated gene families, calibrated using fossil evidence for the ages of species divergences that bracket WGD events.

Effects of repeated light-dark phase shifts on voluntary ethanol and water intake in male and female Fischer and Lewis rats.

Several lines of evidence implicate reciprocal interactions between excessive alcohol (ethanol) intake and dysregulation of circadian biological rhythms. Thus, chronic alcohol intake leads to widespread circadian disruption in both humans and experimental animals, while in turn, chronobiological disruption has been hypothesized to promote or sustain excessive alcohol intake. Nevertheless, the effects of circadian disruption on voluntary ethanol intake have not been investigated extensively, and prior studies have reported both increased and decreased ethanol intake in rats maintained under "shift-lag" lighting regimens mimicking those experienced by shift workers and transmeridian travelers.

Seasonal and diel patterns of biting midges (Ceratopogonidae) and mosquitoes (Culicidae) on the Parris Island Marine Corps Recruit Depot.

The Marine Corps Recruit Depot on Parris Island, SC, is surrounded by tidal salt marshes, which are breeding habitats for many pestiferous biting flies. Knowledge of biting fly behavior patterns is needed to develop effective pest management strategies in urban areas adjacent to salt marshes. We measured biting midge (Ceratopogonidae) and mosquito (Culicidae) seasonal abundance and diel activity patterns on Parris Island using CO(2)-baited suction traps from November 2001 - November 2004.

Repeated light-dark phase shifts modulate voluntary ethanol intake in male and female high alcohol-drinking (HAD1) rats.

Background: Chronic disruption of sleep and other circadian biological rhythms, such as occurs in shift work or in frequent transmeridian travel, appears to represent a significant source of allostatic load, leading to the emergence of stress-related physical and psychological illness. Recent animal experiments have shown that these negative health effects may be effectively modeled by exposure to repeated phase shifts of the daily light-dark (LD) cycle. As chronobiological disturbances are thought to promote relapse in abstinent alcoholics, and may also be associated with increased risk of subsequent alcohol abuse in nonalcoholic populations, the present experiment was designed to examine the effects of repeated LD phase shifts on voluntary ethanol intake in rats.