In his examination, Ruse shows that there is no evidence for a designer, nor a need for a designer. He cites the vertebrate eye, for example, which intelligent design advocates say is too complex to have arisen through natural selection. On the contrary, Ruse reports. Geneticist R.J. Berry, he writes, showed at a conference last summer that the vertebrate eye could have evolved from a simple light-sensitive spot in far less time then was actually available -- 364,000 generations, about 15 times less than there actually were, according to a review of Ruse's book by Alan Batten.
Dawkins has also noted that the eye has evolved at least 40 times independently since life began on Earth, greatly diminishing the claim that it is impossible for the eye to develop through Darwinian processes.
And imperfections in organs such as the eye also weaken the design argument. I recently had an eye doctor assess me, for example, and learned that my previously 20/20 vision had deteriorated. And I'm not alone. Look around you and spot the spectacles.
Rather than designed, we and other organisms appear to have been shaped by our environments, retrofitted as best as possible under the circumstances. In his review for The Globe and Mail, for example, Batten reports an excellent example: The sinus is u-shaped but isn't drained from the bottom of the u. No engineer would make such a mistake, Batten notes. But it would be expected if the sinus arose through natural selection, as previous structures would be adapted.