DNA Analysis Reveals "Positive" Selection

Recent genetic research has found evidence of "positive" evolutionary selection in 544 genes.

Discussions of evidence for evolution being disclosed by DNA analysis is either shallow or absent from the writings of the proponents of creation science and intelligent design. For those of us who believe that God guided the processes of evolution to accomplish his creative purposes, the current research provides much food for thought.

Here's a quote:

The largest group of positively selected genes in primates involved sensory inputs -- including perceptions of taste, color and pain. "The conventional wisdom is that we should see major changes in the brain-related genes," Siepel noted. "We didn't find a signal for that, but did find inputs to the central nervous system." Perhaps, the researchers speculated, changes in sensory input drove changes in the brain.

The study supports the idea that positive selection is important in evolution, Siepel said. Theorists have argued over the relative importance of positive selection versus "neutral drift," where random changes simply happen with no positive or negative result. He noted that positive selection was found mainly in genes that are not expressed in as many tissues as others. "Genes with more specialized purposes may have more freedom for adaptation," he explained.

The researchers also found evidence that many changes seem to have occurred in spurts over short periods of time. For example, they found genes that were not under selection in lower mammals, then came under selection in primates, then were lost in humans. Whether evolution has been continuous or episodic has also been a subject of much debate among biologists.

Blind Salamanders and Unintelligent Design

Christopher Hitchens has posted a thought-provoking essay on Slate about "Losing Sight of Progress." He discusses how salamanders living in subterranean caverns are born with eyes that cannot see. Then he uses this fact to deconstruct faith in "creation science" and "intelligent design." Hitchens shared this insight with Richard Dawkins and received this response:

Vestigial eyes, for example, are clear evidence that these cave salamanders must have had ancestors who were different from them—had eyes, in this case. That is evolution. Why on earth would God create a salamander with vestiges of eyes? If he wanted to create blind salamanders, why not just create blind salamanders? Why give them dummy eyes that don't work and that look as though they were inherited from sighted ancestors?

Hitchens and Dawkins have got a point. I doubt that either creation scientists or intelligent designers can make a satisfactory response to this.

I believe in a creator, but find abhorrent theories like "creation science" and "intelligent design" which prescribe that creation necessarily requires supernatural interventions. All such prescriptions conceal attempts to make both science and God conform to the theorists conception of scriptural hermeneutics.

The Infinite is free to create all the processes of the finite order to accomplish the purposes of Eternity. There's little need for a conflict of interpretations between faith and science. There is much need for a faith that knows how to appropriate the truth that science discovers.

It seems to me that blind salamanders are a good illustration of the folly of prefering darkness to light (John 3:19). These salamanders turned from the light and bred in darkness until they became blind. They thereby condemned their children to live in a very small, dark and confined world -- more like a prison than like the free ranging, wide open spaces of the world above ground.

I suspect that safety and homeland security were on the minds of those first salamanders that fell into their cave. They must have been frightened into that cave by some threat that towered over them. Who can blame them if they found it too traumatizing to climb back to daylight and face the world with their eyes wide open?

If they stayed in the cave until they grew accustomed to their cramped quarters and then went blind, at least they never had to face the terrors they met in the daylight.

And those vestigal blind eyes do have a purpose. They serve as a constant reminder that their progeny will never know what it was like to live in the light.