Insects are the most speciose group of animals, but the phylogenetic relationships of many major lineages remain unresolved. We inferred the phylogeny of insects from 1478 protein-coding genes. Phylogenomic analyses of nucleotide and amino acid sequences, with site-specific nucleotide or domain-specific amino acid substitution models, produced statistically robust and congruent results resolving previously controversial phylogenetic relations hips.
View Article and Find Full Text PDFSummary: New sequence data useful for phylogenetic and evolutionary analyses continues to be added to public databases. The construction of multiple sequence alignments and inference of huge phylogenies comprising large taxonomic groups are expensive tasks, both in terms of man hours and computational resources. Therefore, maintaining comprehensive phylogenies, based on representative and up-to-date molecular sequences, is challenging.
View Article and Find Full Text PDFTo quantify known and unknown microorganisms at species-level resolution using shotgun sequencing data, we developed a method that establishes metagenomic operational taxonomic units (mOTUs) based on single-copy phylogenetic marker genes. Applied to 252 human fecal samples, the method revealed that on average 43% of the species abundance and 58% of the richness cannot be captured by current reference genome-based methods. An implementation of the method is available at http://www.
View Article and Find Full Text PDFBackground: The rapid accumulation of molecular sequence data, driven by novel wet-lab sequencing technologies, poses new challenges for large-scale maximum likelihood-based phylogenetic analyses on trees with more than 30,000 taxa and several genes. The three main computational challenges are: numerical stability, the scalability of search algorithms, and the high memory requirements for computing the likelihood.
Results: We introduce methods for solving these three key problems and provide respective proof-of-concept implementations in RAxML.
Verification in phylogenetics represents an extremely difficult subject. Phylogenetic analysis deals with the reconstruction of evolutionary histories of species, and as long as mankind is not able to travel in time, it will not be possible to verify deep evolutionary histories reconstructed with modern computational methods. Here, we focus on two more tangible issues that are related to verification in phylogenetics (i) the inference of support values on trees that provide some notion about the 'correctness' of the tree within narrow limits and, more importantly; (ii) issues pertaining to program verification, especially with respect to codes that rely heavily on floating-point arithmetics.
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