Non Coding DNA and its effect on evolution
Richard Dawkins discusses this in his book The Greatest Show on Earth: The Evidence for Evolution

Bacteria and other microorganisms, specifically Archaea, are able to exchange in a sort of 'copy and paste' genetic exchange that differs wildly from sexual reproduction.  They can even exchange genes with other distantly related species.  This, coupled with their short (compared to Humans) lifecycle, accounts for much of the difference in evolutionary rates.  Often, it makes sense to speak in terms of evolution in terms of specific genes themselves (in the case of bacteria), as opposed to evolution of the species as a whole, due to the 'copy and paste' exchange that can take place.  For Bacteria, there is something to be said for compiling a 'true' family tree for each gene separately, regardless of which kind of bacteria in which it resides.

Dawkins remarks, "The philosopher Dan Dennett has put it, 'Where the tree of life for animals is a majestically spreading oak, that for bacteria is more like a banyan.'"

Also, evolution by Natural Selection and random mutation does act on 'non-coding' DNA, just to be clear.