Here goes: Creationists believe that absolutely everything was created in just six days. Variation and micro-evolution could occur, but no macro-evolution and no "increases in information" would happen. They also believe that everything was created perfect, no thorns, thistles, and so on. So how did those things come about? Evolution is the only answer. God couldn't have created them, the bible says nothing of neither God nor Satan creating these things. It must have evolved and the only way to do that is through an increase in information.
Let's take an even greater case into mind: How did snake venom come about? Would it have possibly had a pre-Fall use? Let's look at their words about this problem:
The idea that the snake’s fangs may have been used to inject a fruit-softening substance pre-Fall has the same problem. That is, why, how, and when (if not by direct creation) did snakes change not only their diet but their behavior, which appears to be programmed in their genetic code and not a matter of conscious choice?7
In any case, snake venom contains complex chemicals that appear to be designed for purposes far removed from fruit-eating. One of these chemicals is highly specific in its attack on the central nervous system to arrest breathing; another specifically blocks the clotting mechanism so that the prey bleeds to death internally.They took the words right out of my mouth.