It can be reasonably asserted that it was a relative certainty from the start of the universe that there would be organisms with eyes at some future point. For other things, perhaps things like the human brain, this wasn't a certainty at the start of the universe. The first states that organisms with eyes were designed into the universe, the second states that the human brain was designed after that. So now to find the events which influenced the probability of a human brain coming to be. Those are the creation events, from which the human brain originates. You can call them different names then creation or design, but you wouldn't deny that it's interesting to know those events which influenced those probalities greatly.
If you would find a dna-kit lying around among the fossils then that would certainly also constitute circumstantial evidence of design.
regards,
Mohammad Nor Syamsu