Pop Goes the Theory

Scientists thought they had life all figured out. The origin of life, that is. The idea that life evolved from a primordial soup has been elaborated into a network of complex theories. But at a recent conference, the practicing chemists turned thumbs down on all the lovely theories. The occasion was the International Conference on the Origin of Life held a few weeks ago in Barcelona. Charles Thaxton, a biochemist who gave a paper at the conference, tells what happened. The theoretical biologists would stand up and paint a complex picture of chemicals dancing in a primordial ocean, linking up in clever ways to form the long chain molecules crucial to life, like DNA, the molecule of heredity. Then the practicing chemists would stand up, smile apologetically, and say, "The theory sounds good . . . but we just can't get real chemicals to react that way in the laboratory." What has chemists stymied is how to concentrate all the right ingredients in one place. You see, to make chemicals link up, you have to apply energy-heat or electricity. Most origin-of-life theories start with a chemical soup heated by volcanoes or zapped by lightning. But there's a fly in this chemical soup. The chemical reactions that form DNA are reversible: The molecules that come together can separate again. In fact, as every chemist knows, it's actually harder to link molecules together and easier to break them apart. What does that mean for origin-of-life theories? If you simulate the origin of life in a test tube, any organic compounds that form will quickly break up again. You never get enough of them concentrated in one place to form DNA. This one fact makes it impossible for life to have evolved on the early Earth. As Charles Thaxton says in his book The Mystery of Life's Origin, the primordial soup would always be thin and diluted-just as thin as the Atlantic Ocean is today. We've all heard it said that evolution is like millions of monkeys pounding randomly at typewriters for millions of years. One monkey, so the argument goes, would eventually type out a Shakespearean play. But since chemical processes are reversible, the analogy doesn't hold. A better analogy would be that each monkey has a partner nearby, and every time he bangs out a few letters, the second monkey grabs the paper and tears it up. The first monkey bangs out a few more letters; the second monkey tears it up; over and over again. Obviously, these monkeys are never going to produce a Shakespearean play. And by the same token, a chemical soup will never form DNA. For life to emerge, the right organic compounds need to be sorted out and protected so they don't break up. But nature doesn't come equipped with any sorting mechanisms. There's only one thing that can select and sort: an intelligent agent. And when we're talking about the prehistoric world, that means a Creator. So the next time you hear the analogy of the monkeys at the typewriters, be ready to explain what's wrong with it. In our science textbooks the evolution of life from a soup of chemicals may be spun out into elaborate theories. But in the real world, chemicals just don't work that way.

11/3/93