Evolutionary History Simulation
A simulation of the evolutionary history was done using the Seq-gen software32. We used the same tree obtained by phylogenetic inference (see ’Evolutionary Analysis’) with the JTT evolutionary model and a sequence rich in “KK” pairs as sequence seed, in order to calculate the random frequencies of occurrence of “KK”, “KR”, “RK” and “RR” pairs in the tips of the phylogenetic tree.