That's a good question. At one time, "Answers in Genesis" denied that this could happen. Later, when directly observed speciations were documented, there was a problem for them. The solution?
They decided that speciation was true, but that it wasn't really evolution after all:
"Speciation, the formation of new species, is not evolution in action."
Speciation
Problem solved. ;D
Here's a quote from the AIG article you provided a link for. BTW, thanks for the link.
"Created kinds are organisms representing or descended from those originally created by God about 6,000 years ago. Organisms within a created kind generally interbreed and produce only more organisms of their own kind 'within the limits of preprogrammed information, but with great variation.'
5Organisms that can interbreed are of the same created kind, since God designed organisms to reproduce “after their kind.' Due to loss of information and other factors, however, some organisms lose the ability to interbreed. Created kinds correspond roughly to the family level of the current classification taxons but may vary from order to genus level.
"Although evolutionists imbue taxonomic classification with evolutionary implications—believing that the taxonomic groupings roughly depict common ancestry— taxonomy is really nothing more than a useful bookkeeping system to sort and group organisms according to their shared characteristics.
"As creationists, we must frequently remind detractors that we do not deny that species vary, change, and even appear over time. The biodiversity represented in the 8.7 million or so species in the world is a testament, not to random chance processes,
but to the genetic variability and potential for diversification within the created kinds that God built into the genomes of the originals 6,000 years ago." (Emphasis was added.)
Obviously, this is an issue of semantics. I see this a lot in discussions concerning evolution. The fact is that AIG has always maintained that
kinds of creatures don't naturally evolve into other
kinds of creatures. For instance, there can be variations within a certain kind of animal--say dogs--but the end result after any changes is still a dog.