MOST RAPIDLY EVOLVING. “TEs are ubiquitous and abundant genomic sequences. Since TEs tend to be among the most rapidly evolving of all genomic sequences, they may also provide a mechanism for the emergence of lineage-specific miRNA genes that could exert diversifying regulatory effects. many studies have identified a variety ways in which TEs have been domesticated to provide functions to their hosts.” (TE = transposable elements; miRNA = microRNA).
http://www.genetics.org/content/176/2/1323