Cumulative copy numbers for DNA element superfamilies and L1 elements according to age. The age of each family is plotted against the cumulative copy number of the superfamily. See Results and Methods sections for details on the calculation of the age for each family. (1) hAT superfamily elements were more intensively active during the pre-prosimian era (>63 My), decreasing in proliferation during the subsequent primate radiation (<63 My). (2) MuDR and piggyBac (e.g., MER85) superfamily elements were strictly active during the primate radiation. (3) Tc1/mariner (e.g., MADE1, Tigger1) superfamily elements were active before the primate radiation, but experienced a marked burst of activity during the primate radiation.
