MOTIVATION Recent technological advances are allowing many laboratories to sequence their research organisms. Available de novo assemblers leave repetitive portions of the genome poorly assembled. Some genomes contain high proportions of transposable elements, and transposable elements appear to be a major force behind diversity and adaptation. Few de novo assemblers for transposable elements e...

Recent advances in genome sequencing have led to a vast accumulation of transposable element data. Consideration of the genome sequencing projects in a phylogenetic context reveals that despite the hundreds of eukaryotic genomes that have been sequenced, a strong bias in sampling exists. There is a general under-representation of unicellular eukaryotes and a dearth of genome projects in many br...

I t was almost 30 years ago when François Jacob declared that evolutionary innovation (the emergence of novel form and function over time) occurred primarily via a process of ‘‘tinkering’’ (1). By tinkering, Jacob essentially meant the creation of novelty through random combinations of preexisting forms. Two fundamental and countervailing notions are implicit in this view of evolution: optimali...

Circular DNAs are extra-chromosomal fragments that become circularized by genomic recombination events. We have recently shown that yeast LTR elements generate circular DNAs through recombination events between their flanking long terminal repeats (LTRs). Similarly, circular DNAs can be generated by recombination between LTRs residing at different genomic loci, in which case the circular DNA wi...