Bursts of DNA transposon activity. Horizontal bars represent the duration of bursts of Tc1-like DNA transposon in Salmo salar, based on earliest and latest branching. The shaded areas indicate the approximate timing of the genome duplication event (left) and further speciation events  (right).
de Boer et al. BMC Genomics 2007 8:422 doi:10.1186/1471-2164-8-422