Your analogy is highly flawed. A)There's only one way the watch can fit together properly. There are hundreds of thousands of trillions of ways to make a functioning organism. B) Evolution is gradual. The functional organism, or the working watch, doesn't just happen. It takes several steps, several iterations. C) Evolution isn't just shaking random pieces and hoping for the best. Evolution is a process of populations changing based on new environmental factors or mutations that benefit existing conditions. It's far from random. Nice try.