DNA is DNA. Why would it even need to exist, or even evolve to exist if the organisms beforehand were already in a state of environmental equilibrium? Remember the insect scenario in the OP? Those environmental hazards had to have always been present and have to be today in order to discourage this evolutionary process from reversing. We teach our students with what is called an education, and as humans, we pride ourselves on the ability to retain knowledge (Genesis 1:27). Hypothetically, if you were to keep a child ignorant to the world, even until he became an old and infirm individual, how smart would he be? Would he not retain that knowledge after thousands of years of possessing a barrage of ancestors with an astute knowledge of academic wisdom? No. "The primary flaw in the story of macro-evolution is that all plants and animals are packed with information—the complicated instructions that coordinate the many processes enabling the body and brain to function. The greatest weakness of the theory of evolution is that science has not discovered a process that can create all the necessary information, which can be likened to the software that directs a computer" (Philip E. Johnson, Christian Apologist).