Evolutionary Biologists Score One for Darwin
Byline: Greg Bolt The Register-Guard
By resurrecting a protein that disappeared 450 million years ago, a trio of University of Oregon researchers have shown how evolution could have produced the amazingly complex biological systems that some have claimed are evidence of "intelligent design."
The research, published today in Science magazine, provides an evolutionary path for the intricate "lock-and-key" relationship between a hormone and its biological receptor. Proponents of intelligent design contend that such relationships are evidence of "irreducible complexity," meaning they couldn't have evolved from the random changes that fuel natural selection and therefore must have been designed, whether by God or some other higher power.
UO molecular biologist Joseph Thornton said refuting intelligent design wasn't the goal of the research, but he's pleased that it adds to the already robust arguments supporting evolution.
"We do this work because the evolutionary questions, the scientific questions, are extremely interesting," he said. "It turns out they also reveal a major flaw in the arguments of the intelligent design cam- paign."
Intelligent design supporters have challenged the value of the research. The Seattle-based Discovery Institute (www. discovery.org) plans to post a response to the work today, and a leading intelligent design advocate posted comments Thursday saying the research fails to refute the concept of irreducible complexity.
Thornton, a member of the UO's Center for Ecology and Evolutionary Biology, used newly developed genetic techniques to literally re-create the ancestor of the receptor protein for the hormone aldosterone, which regulates the body's salt balance. Scientists previously used mathematical models to re-create virtual ancestor genes, but the new techniques allowed Thornton to re-create the genetic material itself.
"We actually re-create a gene that hasn't existed for 450 million years," Thornton said. "It's amazing, but it opens up all sorts of scientific opportunities for us."
Hormones regulate many biological functions by activating certain genes that direct the body's cells to perform a specific task. But that genetic signal is only triggered when a hormone binds to a receptor protein.
Both hormones and receptors have hugely complex molecular shapes and to function must fit together like an intricate key in an equally intricate lock. But individually, the molecules have no biological or evolutionary purpose, so scientists have puzzled over how they evolved, especially considering that one sometimes appears millions of years before the other.
That's what gave rise to the intelligent design notion of irreducible complexity. …