We have A new “Material and Method” section has been added. Such issues as statistical resampling tests (bootstrap and jackknife), calibration of branch length, the meaning and choice of the peptide length K, etc. , were discussed in the new section. Figures 1 and 2 were combined to a new Figure 1; Figures 3 and 4 were combined to become a new Figure 2. Figure captions were made more detailed. The whole text was checked for language flaws and many places were rephrased.
In summary, I find the piece interesting, but parts of the discussion are rather weak, therefore I am suggesting a major revision. Another reason for major revision is the style that the manuscript is written. I am not a native speaker, but given that I had to read sentences several times, I suspect the manuscript can benefit from an English language check.