Exploring frontiers in the DNA landscape: an introduction to the symposium "Genome Analysis and the Molecular Systematics of Retroelements".

The emerging field of phylogenomics is influencing both the amount and type of characters being brought to bear on long-standing problems in systematic biology. Moreover, the proliferation of sequence information from genome projects in concert with the development of new informatics tools is widening access to comparative data on retroelements to a broad cross section of investigators. Motivated by this, the Society of Systematic Biologists sponsored a symposium entitled "Genome Analysis and the Molecular Systematics of Retroelements," and the resulting papers illustrate this theme of new discoveries and cover three basic areas of research: (i) the taxonomic distribution and phylogenetic structure of families of retroelements; (II) the use of SINE and LINE insertions for phylogenetic inference; and (III) the informatics and classification of repetitive elements. Contributions of each article are briefly discussed in this context and particularly fruitful directions for future research illuminated by results of this symposium are reviewed.