I greeted with enthusiasm Wednesday’s news that a fellow enzyme bioengineer, Cal Tech’s Frances H. Arnold, won part of the 2018 Nobel Prize in Chemistry. She’s a worthy recipient. And the win shines a light on the good work going on in our subdiscipline.
I’ve only one bone of contention—all the breathless talk about “evolution” surrounding this year’s prize.
The official announcement says Arnold and the other two winners “harnessed the power of evolution.” The New York Times runs on in the same vein. At first, “Dr. Arnold attempted ‘rational design,’ employing logic and knowledge of how proteins function to try to build new enzymes.” When she hit a wall, she turned to “directed evolution.”
“I copied nature’s inventions, this wonderful process of evolution, to breed molecules like you breed cats and dogs,” she told the Times.
But this conflates artificial and natural selection. Also, Dr. Arnold never stopped “employing logic and knowledge of how proteins function.”
The term “directed evolution” obscures the reality that the new protein enzymes in her lab were bio-engineered. They were designed.
This year’s winners didn’t harness “the power of evolution.” They demonstrated the power of intelligent design.
Another point of confusion: the term “rational design.” Placing the word “rational” in front of “design” implies that design can be wholly non-rational, wholly separate from the work of creative intelligence, of mind. But that contradicts all generally accepted definitions of design.
Bioengineers start with natural enzymes and uses the tools of genetic engineering to look for ways to modify them for commercial applications. The approach Dr. Arnold came to use involves random and designed aspects. Bioengineers randomly mutate the gene that codes for a given enzyme. Then they search for better functioning mutants among the billions of variants created.
That approach has generated some amazing results. But the technique has its limitations. There has to be a mutational pathway to the new structure. You must be able to create a huge mutant library in order to find the rare positive mutants. You need a rapid screening method to detect the rare positive mutants. And you need an intelligent agent guiding the whole process.
What can nature alone evolve? The Darwinian process can only select for present function, not future function. Each mutational step on the way has to be functional. It can’t look ahead to a distant goal. So how big can a mutational leap be? Chance, after all, can only create so much in a single mutational jump.
In his book “The Edge of Evolution” biochemist Michael Behe drew upon microbial research to find the answer: two to three simultaneous, coordinated mutations. Behe’s conclusion is in harmony with Barry Hall’s results with lactase mutations.
These findings pose a major challenge to modern evolutionary theory. That’s because almost any complex structure you can think of in biology would require nature to make numerous leaps far bigger than this to successfully evolve the new structure from a simpler precursor. And since the calculations are both empirically and mathematically rigorous, they can’t just be wished away.
And here is the really interesting part: Bioengineers, including the 2018 Nobel Laureates in Chemistry, are demonstrating a way to reach beyond this limit — intelligent agency. Their brilliantly designed experiments involve mutation rates artificially engineered to occur at 10,000 to a million times the rate typical in nature. They involve carefully selected reaction conditions. They require the intelligently selected use of genetic engineering tools (tools that are themselves intelligently designed). And they require the mindful selection of variants towards a desired goal.
All of these actions are hallmarks of intelligent design.
Matti Leisola, DSc, is co-author of “Heretic: One Scientist’s Journey from Darwin to Design.” The former dean of Chemistry and Material Sciences at Helsinki University of Technology, Leisola has published 140 peer-reviewed articles and served as biotech research director for Cultor, an international biotech company. He co-founded the International Society of Rare Sugars.