Fig. 3.
The number of HTTs between insects negatively correlates with insect divergence time. This trend is significant for both DNA transposons (red points) and retrotransposons (blue points) (P ∼ 4 × 10−3 and P < 10−4, respectively; two-sided Mantel tests). Number of transfers were averaged over pairs of lineages assigned to each 10 My-wide class of divergence time. To avoid bias due to differences in the number of species per lineage, we randomly sampled one species per lineage and computed averages over 104 samplings.