The irreducible complexity argument was developed by Michael Behe and first used in his book Darwin's Black Box. The argument is that some biological systems are so complex that they can not have evolved though mutation and natural selection; it you remove one peace, it brakes, it no longer functions. Creationists often use the analogy [...]

Expelled Exposed has made a video about the evolution of the eye. And cdesign proponentsists say the eye is to complex to have evolved.