Darwin’s Black Box
Darwin's Black Box: The Biochemical Challenge to Evolution is a 1996 book written by scientist Michael Behe in which he argues that many biochemical systems are irreducibly complex. This means in order to function in their current form, they could not have had precursors in their development. No series of intermediary steps could have achieved a working result. Therefore, by logical process of elimination, they must be the result of intelligent design rather than having occurred through a natural evolutionary processes.
Several examples are cited. The modern movement for intelligent design was given a strong boost from Behe's book.