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Full-Text Articles in Life Sciences

The Fossilized Birth–Death Process For Coherent Calibration Of Divergence-Time Estimates, Tracy A. Heath, John P. Huelsenbeck, Tanja Stadler Jul 2014

The Fossilized Birth–Death Process For Coherent Calibration Of Divergence-Time Estimates, Tracy A. Heath, John P. Huelsenbeck, Tanja Stadler

Tracy Heath

Time-calibrated species phylogenies are critical for addressing a wide range of questions in evolutionary biology, such as those that elucidate historical biogeography or uncover patterns of coevolution and diversification. Because molecular sequence data are not informative on absolute time, external data—most commonly, fossil age estimates—are required to calibrate estimates of species divergence dates. For Bayesian divergence time methods, the common practice for calibration using fossil information involves placing arbitrarily chosen parametric distributions on internal nodes, often disregarding most of the information in the fossil record. We introduce the “fossilized birth–death” (FBD) process—a model for calibrating divergence time estimates in a …


Another Look At The Root Of The Angiosperms Reveals A Familiar Tale, Bryan Drew, Brad Ruhfel, Stephen Smith, Michael Moore, Barbara Briggs, Matthew Gitzendanner, Pamela Soltis, Douglas Soltis Feb 2014

Another Look At The Root Of The Angiosperms Reveals A Familiar Tale, Bryan Drew, Brad Ruhfel, Stephen Smith, Michael Moore, Barbara Briggs, Matthew Gitzendanner, Pamela Soltis, Douglas Soltis

Brad R. Ruhfel

Since the advent of molecular phylogenetics more than 25 years ago, a major goal of plant systematists has been to discern the root of the angiosperms. Although most studies indicate that Amborella trichopoda is sister to all remaining extant flowering plants, support for this position has varied with respect to both the sequence data sets and analyses employed. Recently, Goremykin et al. (2013) questioned the “Amborella-sister hypothesis” using a “noise-reduction” approach and reported a topology with Amborella + Nymphaeales (water lilies) sister to all remaining angiosperms. Through a series of analyses of both plastid genomes and mitochondrial genes, we continue …


From Algae To Angiosperms – Inferring The Phylogeny Of Green Plants ( Viridiplantae ) From 360 Plastid Genomes, Brad Ruhfel, Matthew Gitzendanner, Paula Soltis, Douglas Soltis, J. Burleigh Dec 2013

From Algae To Angiosperms – Inferring The Phylogeny Of Green Plants ( Viridiplantae ) From 360 Plastid Genomes, Brad Ruhfel, Matthew Gitzendanner, Paula Soltis, Douglas Soltis, J. Burleigh

Brad R. Ruhfel

Background

Next-generation sequencing has provided a wealth of plastid genome sequence data from an increasingly diverse set of green plants (Viridiplantae). Although these data have helped resolve the phylogeny of numerous clades (e.g., green algae, angiosperms, and gymnosperms), their utility for inferring relationships across all green plants is uncertain. Viridiplantae originated 700-1500 million years ago and may comprise as many as 500,000 species. This clade represents a major source of photosynthetic carbon and contains an immense diversity of life forms, including some of the smallest and largest eukaryotes. Here we explore the limits and challenges of inferring a comprehensive green …


Boosting The Performance Of Bayesian Divergence Time Estimation With The Phylogenetic Likelihood Library, Diego Darriba, Andre Aberer, Tomas Flouri, Tracy A. Heath, Fernando Izquierdo-Carrasco, Alexandros Stamatakis Apr 2013

Boosting The Performance Of Bayesian Divergence Time Estimation With The Phylogenetic Likelihood Library, Diego Darriba, Andre Aberer, Tomas Flouri, Tracy A. Heath, Fernando Izquierdo-Carrasco, Alexandros Stamatakis

Tracy Heath

We present a substantially improved and parallelized version of DPPDiv, a software tool for estimating species divergence times and lineage-specific substitution rates on a fixed tree topology. The improvement is achieved by integrating the DPPDiv code with the Phylogenetic Likelihood Library (PLL), a fast, optimized, and parallelized collection of functions for conducting likelihood computations on phylogenetic trees. We show that, integrating the PLL into a likelihoodbased application is straight-forward since it took the first author (DD) a programming effort of only one month, without having prior knowledge of DPPDiv, nor the PLL. We achieve sequential speedups that range between a …


Combined Morphological And Molecular Phylogeny Of The Clusioid Clade (Malpighiales) And The Placement Of The Ancient Rosid Macrofossil Paleoclusia, Brad Ruhfel, Peter Stevens, Charles Davis Dec 2012

Combined Morphological And Molecular Phylogeny Of The Clusioid Clade (Malpighiales) And The Placement Of The Ancient Rosid Macrofossil Paleoclusia, Brad Ruhfel, Peter Stevens, Charles Davis

Brad R. Ruhfel

Premise of research. The clusioid clade is a member of the large rosid order Malpighiales and contains∼1900 species in five families: Bonnetiaceae, Calophyllaceae, Clusiaceae sensu stricto (s.s.), Hypericaceae, and Podostemaceae. Despite recent efforts to clarify their phylogenetic relationships using molecular data, no such data are available for several critical taxa, including especially Hypericum ellipticifolium (previously recognized in Lianthus), Lebrunia, Neotatea, Thysanostemon, and the second-oldest rosid fossil (∼90 Ma), Paleoclusia chevalieri. Here, we (i) assess congruence between phylogenies inferred from morphological and molecular data, (ii) analyze morphological and molecular data simultaneously to place taxa lacking molecular data, and (iii) use ancestral …


Phylogenomics And A Posteriori Data Partitioning Resolve The Cretaceous Angiosperm Radiation Malpighiales, Zhenxiang Xi, Brad Ruhfel, Hanno Schaefer, André Amorim, M. Sugumaran, Kenneth Wurdack, Peter Endress, Merran Matthews, Peter Stevens, Sarah Mathews, Charles Davis Oct 2012

Phylogenomics And A Posteriori Data Partitioning Resolve The Cretaceous Angiosperm Radiation Malpighiales, Zhenxiang Xi, Brad Ruhfel, Hanno Schaefer, André Amorim, M. Sugumaran, Kenneth Wurdack, Peter Endress, Merran Matthews, Peter Stevens, Sarah Mathews, Charles Davis

Brad R. Ruhfel

The angiosperm order Malpighiales includes ∼16,000 species and constitutes up to 40% of the understory tree diversity in tropical rain forests. Despite remarkable progress in angiosperm systematics during the last 20 y, relationships within Malpighiales remain poorly resolved, possibly owing to its rapid rise during the mid-Cretaceous. Using phylogenomic approaches, including analyses of 82 plastid genes from 58 species, we identified 12 additional clades in Malpighiales and substantially increased resolution along the backbone. This greatly improved phylogeny revealed a dynamic history of shifts in net diversification rates across Malpighiales, with bursts of diversification noted in the Barbados cherries (Malpighiaceae), cocas …


Phylogeny Of The Clusioid Clade (Malpighiales): Evidence From The Plastid And Mitochonrial Genomes, Brad R. Ruhfel, Volker Bittrich, Claudia A. Bove, Mats H.G. Gustafsson, C. Thomas Philbrick, Rolf Rutsihauser, Zhenxiang Xi, Charles C. Davis Dec 2010

Phylogeny Of The Clusioid Clade (Malpighiales): Evidence From The Plastid And Mitochonrial Genomes, Brad R. Ruhfel, Volker Bittrich, Claudia A. Bove, Mats H.G. Gustafsson, C. Thomas Philbrick, Rolf Rutsihauser, Zhenxiang Xi, Charles C. Davis

Brad R. Ruhfel

• Premise of the study : The clusioid clade includes five families (i.e., Bonnetiaceae, Calophyllaceae, Clusiaceae s.s., Hypericaceae, and Podostemaceae) represented by 94 genera and ~1900 species. Species in this clade form a conspicuous element of tropical forests worldwide and are important in horticulture, timber production, and pharmacology. We conducted a taxon-rich multigene phylogenetic analysis of the clusioids to clarify phylogenetic relationships in this clade.

• Methods : We analyzed plastid ( matK , ndhF , and rbcL ) and mitochondrial ( matR ) nucleotide sequence data using parsimony, maximum likelihood, and Bayesian inference. Our combined data set included 194 …


The Evolution Of Flight In Insects: Insights From Mayflies And Dna, T. Heath Ogden Dec 2008

The Evolution Of Flight In Insects: Insights From Mayflies And Dna, T. Heath Ogden

T. Heath Ogden

No abstract provided.


Evolution, Jonathan Eisen Dec 2006

Evolution, Jonathan Eisen

Jonathan A. Eisen Ph.D.

No abstract provided.