Tell that to the genius Richard Dawkins, he is the one that felt the need to invoke Aliens in the face of irreducible complexity.
While it may be true that step by step the extremely complex DNA molecule could have been formed purely by chance, the chance of that occurring is so ridiculously low it borders on the impossible, as Dawkins was apparently aware and under such pressure made a fool out himself.
First, no one, not one single person, certainly no scientist working on origin of life issues, thinks DNA "formed purely by chance".
Secondly, the DNA molecule is not "irreducibly complex," nor have IDers ever argued that it is IC. They use entirely different arguments (e.g. "specified complexity") with regard to DNA, and these with regard to the information component, not the molecule as such. (Nor by the way is the informational DNA code IC. Even a high school freshman learns that it is redundant.)
Sorry to be blunt, but you don't seem to know what you're arguing for any better than you know what you're arguing against.