EDIT: Disregard this comment. I found what I was thinking of and it isn't in any way a replicator. It was this: http://www.conwaylife.com/wiki/Gemini
My memory is evidently playing tricks with me. I could have sworn I heard about someone constructing a replicator maybe about a year or 2 ago, and that it was all over the internet. But now when I try to look things up what I find agrees with you that no replicator has yet been constructed. Does anyone know what I might have been thinking of?
(Of course, now we're discussing replicators, whereas the question was about imperfect replicators, but that falls much under the same boat - definitely possible, almost certainly not yet constructed.)
Conway’s Game of Life is Turing-complete. Therefore, it is possible to create an AI in it. If you created a 3^^3 by 3^^3 Life board, setting the initial state at random, presumably somewhere an AI would be created. Would this AI somehow take over the whole game board, if given enough time?
Would this be visible from the top, as it were?
EDIT: I probably meant 3^^^3, sorry. Also, by generating at random, I meant 50% chance on. But any other chance would work too, I suspect.