Hee hee hee!
IMO, which is equally valid here, science operates according to a set of axioms, such as:
-Our perceptions are of an objective, physical universe: it is not the case, as some Buddhists claim, that the physical world is illusory.
-Relevantly similar causes under relevantly similar conditions beget relevantly similar effects, and will continue to do so.
-The basic principles of formal logic apply to our universe: if P is true, then ~P is false.
There may be others.
A creationist may choose to reject these, in favor of another axiom, such as:
-Everything in the King James Bible is literally true.
If you argue against it using scientific axioms (The Bible states both P and ~P, and both of these cannot both be true), you will fail, unless the person you’re arguing with accepts the axiom that the principles of formal logic apply to our universe. More often than you might think, YECs don’t accept the principles of formal logic as a valid tool by which the Bible may be critiqued.
My suggestion, then, is to find out what axioms y’all can agree on. If you can’t agree to accept the principles of formal logic and reason, then your starting points are too far removed from one another to engage in a fruitful discussion.
If you can get your co-worker to accept the three axioms I listed above, however, and if you want to argue, then my suggestion would be to set some ground rules. Ask the co-worker to present a single argument that he considers to be a strong argument against the theory of evolution by natural selection. Get him to agree to discuss only that argument for the time being. Then refuse to engage in any side arguments, relentlessly, boringly, returning to his one argument until either he concedes its fallaciousness, you concede its accuracy, or the two of you agree there’s no progress to be made.
Don’t let him move to another area!
Daniel