Accelerated evolution and positively selected sites in ROBO4.

The table shows the values of log likelihoods () and the estimates of parameters under different models of the rate of evolution among the codons of ROBO4. The models were applied to the small dataset only. The first group of models average the rates of evolution over the entire tree. The model assuming one parameter (i.e., the one-ratio model) calculates , which equaled 0.1095, for the entire tree. This model was least likely (). The next group of models allow the rate of evolution to vary between branches. The free-ratio model calculates a separate rate of evolution for each branch. The branch model calculates one rate of evolution for the ROBO4 branch (foreground) and the other for the remaining branches (background). The branch-site model allows the rate of evolution to vary both among sites and between the foreground and background.