Precisely how, pray tell?
And science by the definition given to us by the dictionary includes much more than naturalism.
Perhaps it's more accurate to say that science assumes regularity; i.e. the assumtion that powerful invisible beings aren't engaged in a vast conspiracy to put their thumbs on the scales to throw off our observations about the world.
IOW: Science does not assume naturalism, per se. Science only assumes that the universe as we can detect it isn't lying to us.
Which, according to James Randi, is one reasons that so many scientists have been hoodwinked by the likes of Uri Geller. Or Piltdown Man or socialism, for that matter. Natural phenomena don't lie, their colleagues almost never do, and so a disproportionate number of scientists seem to be a bit naive about dishonesty and fraud. I think this accounts for some of the outrage that the scientifically-minded express on the crevo threads; they are not used to being blatantly lied to, over and over again.
I find one of the most convincing arguments a creationist can make is that humans are the only animals that are not naked...