I have two files with about 4 fasta sequences each in the PHYLIP format for Da/Ds (Ka/Ks) comparison. After a search on the net, I found that the best software to do so is PAML and it requires a control file and 2 input files. For the tree input, I used PHYML which accepts PHYLIP file inputs and gives NEWICK format outputs. However I am unsure as to how to get the sequence file. I tried the sequential format but it gives me the "Error in sequence data file" error.
Could I get some advice on what is wrong with my input file please. Also, this is just one set of the sequences which I wanted to compare. How do I compare two sets of sequences for the Da/Ds values. I know that this might be basic so thank you for your patience.