The Lost World - Michael Crichton [90]
“Okay,” Kelly said. “So, what’s the big deal now?”
Malcolm smiled. “The big deal,” he said, “is that everybody agrees evolution occurs, but nobody understands how it works. There are big problems with the theory. And more and more scientists are admitting it.”
Malcolm pushed his plate away. “You have to track the theory,” he said, “over a couple of hundred years. Start with Baron Georges Cuvier: the most famous anatomist in the world in his day, living in the intellectual center of the world, Paris. Around 1800, people began digging up old bones, and Cuvier realized that they belonged to animals no longer found on earth. That was a problem, because back in 1800, everybody believed that all the animal species ever created were still alive. The idea seemed reasonable because the earth was thought to be only a few thousand years old. And because God, who had created all the animals, would never let any of his creations become extinct. So extinction was agreed to be impossible. Cuvier agonized over these dug-up bones, but he finally concluded that God or no God, many animals had become extinct—as a result, he thought, of worldwide catastrophes, like Noah’s flood.”
“Okay . . .”
“So Cuvier reluctantly came to believe in extinction,” Malcolm said, “but he never accepted evolution. In Cuvier’s mind, evolution didn’t occur. Some animals died and some survived, but none evolved. In his view, animals didn’t change. Then along came Darwin, who said that animals did evolve, and that the dug-up bones were actually the extinct predecessors of living animals. The implications of Darwin’s idea upset lots of people. They didn’t like to think of God’s creations changing, and they didn’t like to think of monkeys in their family trees. It was embarrassing and offensive. The debate was fierce. But Darwin amassed a tremendous amount of factual data—he had made an overwhelming case. So gradually his idea of evolution was accepted by scientists, and by the world at large. But the question remained: how does evolution happen? For that, Darwin didn’t have a good answer.”
“Natural selection,” Arby said.
“Yes, that was Darwin’s explanation. The environment exerts pressure which favors certain animals, and they breed more often in subsequent generations, and that’s how evolution occurs. But as many people realized, natural selection isn’t really an explanation. It’s just a definition: if an animal succeeds, it must have been selected for. But what in the animal is favored? And how does natural selection actually operate? Darwin had no idea. And neither did anybody else for another fifty years.”
“But it’s genes,” Kelly said.
“Okay,” Malcolm said. “Fine. We come to the twentieth century. Mendel’s work with plants is rediscovered. Fischer and Wright do population studies. Pretty soon we know genes control heredity—whatever genes are. Remember, through the first half of the century, all during World War I and World War II, nobody had any idea what a gene was. After Watson and Crick in 1953, we knew that genes were nucleotides arranged in a double helix. Great. And we knew about mutation. So by the late twentieth century, we have a theory of natural selection which says that mutations arise spontaneously in genes, that the environment favors the mutations that are beneficial, and out of this selection process evolution occurs. It’s simple and straightforward. God is not at work. No higher organizing principle involved. In the end, evolution is just the result of a bunch of mutations that either survive or die. Right?”
“Right,” Arby said.
“But there are problems with that idea,” Malcolm said. “First of all, there’s a time problem. A single bacterium—the earliest form of life—has two thousand enzymes. Scientists have estimated how long it would take to randomly assemble those enzymes from a primordial soup. Estimates run from forty billion years to one hundred billion years. But the earth is only four billion years old. So, chance alone seems too slow. Particularly since we know bacteria actually appeared