There are some really neat things going on here! If you're interested in this, check out a paper by one of my old mentors: Darwinian evolution can follow only v

There are some really neat things going on here! If you're interested in this, check out a paper by one of my old mentors: Darwinian evolution can follow only very few mutational paths to fitter proteins. (http://www.ncbi.nlm.nih.gov/pubmed/16601193 http://www.ncbi.nlm.nih.gov/pubmed/16601193) In general, the more deleterious a mutation, the more mutational paths we see for escaping a local minima. (The rate of compensatory mutation in the DNA bacteriophage phiX174 http://www.ncbi.nlm.nih.gov/pubmed/15911582 http://www.ncbi.nlm.nih.gov/pubmed/15911582)