I really can’t understand the minds of creationists when they say things like “mutations only remove information” when it is clear they have no idea what mutations really are. There are several basic types of mutation, only one of which could really be said to 'remove' information (deletions), but even then, if the deletion causes a frame-shift then it has the potential to make a completely different protein (generally harmful, but a small chance for a beneficial mutation). The other mutation types either add, rearrange or replace DNA.
Not only does their claim parade their ignorance of how mutations actually manifest, they seem to ignore or overlook the fact that beneficial mutations, that allow organisms to perform functions that they previously could not do have been observed. Every time a bacteria develops a resistance to a particular drug, it is because its DNA mutated. It was not resistant to this drug before. This is something new. It is a new function, or an extension of a function the organism already possessed. Either way you look at it, it is an increase in functionality and 'information'.
Not only have we observed bacteria becoming resistant to antibiotics, we have observed other beneficial mutations in bacteria, such as in Richard Lenski's long-term evolution experiment, and in the case of Nylonase (an example of a beneficial frame-shift mutation). In both of these cases, the bacteria developed the ability to digest a new substance and use it for fuel that it previously was unable to digest. This is not a loss of information, it is an increase.
Not only do they deny this solid evidence, they have to invent bullshit about there being limits to the variation that can arise from mutation. There is no biochemical mechanism preventing an organism from accumulating mutations to the point that would be considered another species. In fact we have even observed speciation. The only thing we haven’t observed is a change from a major group of animals to another, and we can demonstrate quite clearly that this happened in the past. Through genetic analysis of similar species (and even distantly related species) we can determine approximately how long ago the common ancestor was between them, through the amount of genetic material they have in common.