Reason For Diversification Of A Gene

Question

[Pappu]

A gene has diverged in sequence during evolution. Is there is any way to find out if it is due to functional requriments or just lack of contraints? Kimura and others has shown that most changes are due to genetic drift. Can one find out the reason by calculating dN/dS and fitting branch and site based evolutionary models using PAML?

[Giovanni M Dall'Olio]

please never say "Kimura etc" :-). In any case the debate between neutralism and selectionism is still open, and I don't think it is correct to say that random drift is the main force driving evolution. I recommend you to read the paper by Nei 2005 for an overview.

Answer 1

[DG]

You can do lots of things to address this question. As you said you can look and do branch/site tests for detecting evidence of positive/diversifying selection on the gene.