In my last post, we looked at the evidence for the theory of design vs. unguided evolution. But one of the main arguments against design according to Dawkins is poor design. His reasoning is that there are aspects of living systems that are cobbled together and contradict what we would expect from an intelligent “Watchmaker”. As with Dawkins’ other refutations of the watchmaker argument, Paley had in fact already addressed them. He said that apparent inferior design did not negate a watchmaker nor did it matter if we could not figure out what each part did. This would be true whether the imperfections were on account of our limited understanding or shortfalls in design (Natural Theology pg 4 &5).
But, are the examples of poor design that Dawkins cites accurate? Again we come back to the example of the eye. The vertebrate eye according to Dawkins and many others in the field of biology is poorly designed. Cephalopod eyes are wired properly, with the photo-receptors pointing outwards, but vertebrate eyes are wired backward with the photo-receptors pointing away from the light source facing the back of the retina. The reasoning goes that this is an accident of evolution and that no engineer in their right mind would design an eye that way. (The Blind Watchmaker pg.132) This idea stuck until the weight of evidence eventually forced all but the most die-hard flawed design proponents to acknowledge that not only is the “backward” wiring not a bad design, it is optimal.
There are actually at least three reasons why this is true. First, there is the choroid layer. This part of the eye is the highly vascularized area immediately adjacent to the presumed backward-facing rods and cone photoreceptors. It provides the photo-receptors with much-needed oxygen and nutrients. This is especially important for the cone cells that we need for color vision as they require more energy than almost any other cells in our bodies. In addition to this, there are many “waste” products associated with vision that need to be recycled and this again requires access that the choroid layer provides. A final reason for the choroid layer being next to the photoreceptors is that the chemical processes involved in sight generate heat and in order for the eyes not to overheat the vascular system is required for cooling.
The second reason for the inverted design (note: I am not using the term "backward”!) is that there are photoreceptors in some of the “wiring” cells that are involved in pupil dilation. The benefit of having these before the rods and cones help determine the amount of light reaching the primary photosensitive cells. Third, the wiring cells are just the right height and width to act as light filters receiving the light that comes into the retina. As a result, they focus the red and green wavelengths of light onto to the cones where color is detected while allowing the blue light to disperse onto the rods thereby vastly improving our color vision. Needless to say, these discoveries were made in spite of the prevailing attitude that the vertebrate eyes were wired backward.
The other example that Dawkins cites of poor design is the DNA itself. He makes reference to this in The Blind Watchmaker but in a more recent book he elaborates:
“It stretches even their [theists] creative ingenuity to make a convincing reason why an intelligent designer should have created a pseudogene — a gene that does absolutely nothing and gives every appearance of being a superannuated version of a gene that used to do something — unless he was deliberately setting out to fool us. Leaving pseudogenes aside, it is a remarkable fact that the greater part (95 percent in the case of humans) of the genome might as well not be there, for all the difference it makes.
But again it was wrong to assume that noncoding DNA was junk. While there is no known function currently for over 90% of the human genome, whole new areas of study are opening up to discover what is going on in this unexplored area of genetics. A massive project undertaken by over 450 scientists called Encode is currently looking to describe noncoding DNA in that same way that the earlier Human Genome Project described our genome. They are finding function in these regions discovering their roles including functioning as switches, enhancers, suppressors, and regulators. But that is only the tip of the iceberg. Other researchers are discovering that the way the DNA is read is impacted by its three-dimensional shape. This fact not only opens new areas of function to the noncoding DNA but also brings into play the potential of a histone code which also appears to be connected to noncoding DNA. If that is not awe-inspiring yet another team of investigators, the aptly named 4D group, is adding time to the mix looking into its effect on the meaning in the 4D structure of DNA!
Granted there is still a debate as to whether or not there is any validity in the term “junk DNA” but for Dawkins part when confronted with the results of ENCODE in a recent debate stated:
I have noticed that there are some creationists who are jumping on [the ENCODE results] because they think that's awkward for Darwinism. Quite the contrary it's exactly what a Darwinist would hope for, to find usefulness in the living world....
My point in sharing this quote is not to make things “awkward” for Richard Dawkins, I am glad that he is willing to embrace new evidence, my concern is how quickly and completely biologists are ready to label something as junk, vestigial, or poorly designed without evidence simply because it fits with their theory that life is the result of an unguided process. Ponder this: the vertebrate eye with its inverted design has been shown to be sensitive enough to detect a single photon of light! If this were an invention of a human being no one would be talking about poor design, it would be hailed as a marvel. And while it will take decades to decipher all that’s going on in our own DNA, (Which if untangled from its 3D shape and laid end to end would reach Pluto!) for the sake of research let’s assume there is a watchmaker whatever our philosophic beliefs. It makes for better science.