Why HIV is so successful

In people with untreated HIV infection, every possible point mutation in the entire genome arises daily

which the authors of this commentary in Nature Immunology note, gives the immune system a very difficult job. Of course, the ability of HIV to increase fitness from random mutation demonstrates that natural selection and evolution do occur. My sense is that most thoughtful creationists (and no, I don't think that is necessaryily an oxymoron) accept this sort of small scale evolution but deny that evolution could explain the emergence of new species.