A "clever designer" should also be capable of avoiding elementary design mistakes. For instance, light receptor cells in the human eye are "back to front", necessitating the "blind spot" as nerves pass through the eye wall to the brain. Similarly, food/drink and air are both introduced to the body through the same orifice, often causing choking. All humans grow a tail during the first four to seven weeks of gestation, which is later absorbed. Hundreds of species of cave fish are blind, yet still possess functionless eyes (a perfect example of evolution in motion, rather than any "intelligent designer"). Thus, the evidence points to either a rather "Stupid Designer", or natural selection via minor mutations over time in a "survival of the fittest" model of evolution as described by Darwin.
(from RationalWiki)