Back in 2007 (you see I’m late, as ever) Allen MacNeill published a list of 47 sources of variation within living cells. I believe he’s since expanded it to over 50. As you’ll see from the link, his intention was to knock down an ID “straw man” that random point mutation cannot produce nearly enough variation to give natural selection traction. Every evolutionary biologist, he points out, can refute that from the hosts of other mechanisms now known to occur.
His critique of ID is a little unfair, I feel, having seen firsthand how often orthodox Neodarwinists knock down ID on the basis that point mutations are more than sufficient, or even unnecessary, to keep natural selection humming along. Certainly that is the case on BioLogos, where relatively little has been discussed in articles about epigenetics, gene splicing and so on. But he still makes a very cogent point. The year after his blog, MacNeill participated in a long and very fruitful (not to say educational and unusually good natured) discussion on this, and other, matters on Uncommon Descent. As he put it then:
…the engines of variation are more than up to the task of generating anything that could conceivably be of use to a living organism (plus an immensely larger amount of useless variation).