SCIENCE FOCUS

Andrew Parker: Evolution, the light-switch theory and the scriptures

Zoologist Andrew Parker puts a strange twist on Genesis and its description of the early earth

PUBLISHED : Sunday, 19 April, 2015, 7:14am
UPDATED : Monday, 20 April, 2015, 12:16pm

Some evolutionary biologists are atheists, others are not. The most (in)famous - even militant - atheist biologist today is no doubt Richard Dawkins, author of the highly influential bestseller The Selfish Gene. In the opposing camp, Francis Collins is a well-known Christian with impeccable scientific credentials. Collins, who was director of the Human Genome Project, calls DNA "the language of God".

Let me now introduce another biologist, Andrew Parker. The University of Oxford zoologist is not as famous as those two, but I find him more intriguing both for his highly original theory and the religious meaning he draws from it. You might have read about how Zen Buddhism and the Tao Te Ching, the ancient Chinese religious text, supposedly anticipated key insights from modern quantum mechanics. Parker makes a similar comparison between the scriptures and evolutionary biology.

After developing the so-called light-switch theory of the Cambrian era in the early 2000s, Parker comes to believe that Genesis is a pretty accurate account of the early formation of the earth and the evolution of life. Remember the six days of creation - how from the void came light, and waters divided the land and the sky (heaven), and how plants and beasts emerged, all at God's command.

The key here is light. For Parker, it made light-sensitive organs possible, from which the eye would eventually emerge. And biological vision, which happened around 543 million years ago, triggered the Cambrian explosion - evolution's Big Bang - from which new species, body shapes, organs, predation and defences emerged. Collins himself reacted to Parker's book, In the Blink of An Eye, in the following way:

"As I see it, a predator evolved for the first time a working visual system, and was so successful that the other organisms had to evolve hard parts to survive, which produced the so-called Cambrian explosion. [Parker's] arguments seem very plausible to me." How ironic! Christians who reject evolutionary theory, especially those of the "intelligent design" school, usually cite the eye as being too complex to have ever been the result of evolution. Boy, if only they had read Parker.

On his light-switch theory, the history of life on earth is divided into two parts: pre-vision and vision. "The rules of life were very different in each, hence there would have been behavioural and evolutionary chaos associated with the transition," Parker wrote.At the start of the Cambrian period, the chemistry of the oceans and the earth's atmosphere changed rapidly to allow much more sunlight in than before. Until then, all animal life had been confined to the seas. Animals with light-sensitive organs gained advantage over those without. As primitive eyes evolved, animals no longer had to rely on proximate senses like touch and smell, but distant vision. An arms race was set off between predators and prey, each side evolving ever more complex body parts and behaviour for defence and attack, with ever sharpening perception and agility.

Under the remorseless selection pressures of the Cambrian explosion, camera-style retinas triggered, directly and indirectly, the rapid evolution of claws, jaws, shells and other defensive body parts. Nervous systems developed as part of the evolution of the eye and the brain. New predatory behaviour and counter-measures evolved. With vision for predators, for example, prey developed camouflage. Those that didn't adapt died out.

The light-switch theory is highly controversial among biologists, but it was cited with approval by Daniel Dennett, the influential US philosopher, in the March issue of Scientific American. You can see why Genesis could have such a powerful hold on Parker's imagination: "Now the earth was formless and empty, darkness was over the surface of the deep, and the Spirit of God was hovering over the waters.

"And God said, 'Let there be light', and there was light."

Parker wrote in The Genesis Enigma: Why the Bible is Scientifically Accurate: "When the biblical text is taken literally, it is left in the wake of advancing science. But when it is read figuratively, it not only keeps pace with the hottest science, it precedes or heralds it."

That's something we may well doubt.