TRANSPOSABLE ELEMENT DRIVERS. “In terms of evolution, this means that the greatest differences between eukaryotic genomes will correspond to TE sequences. In this sense, TEs can be considered as drivers of genome diversification. This may be uninteresting if TEs serve only to replicate themselves and do not play any role for their host genomes as the selfish DNA theory of TEs holds.” (TE = transposable elements).
http://www.genetics.org/content/176/2/1323