Most creationists will use evolution / natural selection to attempt to reconcile the fantasy bible-stories with facts.
The best example is the number of animals in the ark. When the bible was written it gave the dimensions (well, in vague units but 'good enough') but of course they had no idea of the sheer quantity of animal life on the planet outside of their small area of experience. So we have two facts that are completely at odds - the size of the ark to fit all the animals in and a massive number of animals that could never have fit into such a space even if they were liquidized and poured in from the top, never mind survived for weeks on end.
So creationists will claim evolution created the diversity after the flood but in a much shorter time than evolutionists even believe it all happend!
But then they will deny the possibility that the same processes could possibly have led to the emergence of differenct species over vastly longer time periods.
What many fail to comprehend is that creationists (and the religious in general) are often not looking for a comprehensive explanation to life, the universe and everything where each fact has to fit in with what is already known and what has been proven.
They are happy to leap between ideas and as long as they have something to argue the immediate point against them they they will take it, regardless of whether it totally contradicts some other 'belief' that they have.