Levine lowered his binoculars and stared. A deep trumpeting sound reverberated through the air, so loud it hurt his ears. The ground began to shake, making the high hide sway back and forth precariously.
My God, he thought. They’re coming right for me. He bent over, and with fumbling fingers, searched his backpack for the radio.
Problems of Evolution
In the trailer, Thorne took the rehydrated meals out of the microwave, and passed the plates around the little table. Everyone unwrapped them, and began to eat. Malcolm poked his fork into the food. “What is this stuff?”
“Herb-baked chicken breast,” Thorne said.
Malcolm took a bite, and shook his head. “Isn’t technology wonderful?” he said. “They manage to make it taste just like cardboard.”
Malcolm looked at the two kids seated opposite him, who were eating energetically. Kelly glanced up at him, and gestured with her fork at the books strapped into a shelf beside the table. “One thing I don’t understand.”
“Only one?” Malcolm said.
“All this business about evolution,” she said. “Darwin wrote his book a long time ago, right?”
“Darwin published The Origin of Species in 1859,” Malcolm said.
“And by now, everybody believes it, isn’t that right?”
“I think it’s fair to say that every scientist in the world agrees that evolution is a feature of life on earth,” Malcolm said. “And that we are descended from animal ancestors. Yes.”
“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 only four hundred million years after the earth began. Life appeared very fast—which is why some scientists have decided life on earth must be of extraterrestrial origin. Although I think that’s just evading the issue.”
“Okay . . .”
“Second, there’s the coordination problem. If you believe the current theory, then all the wonderful complexity of life is nothing but the accumulation of chance events—a bunch of genetic accidents strung together. Yet when we look closely at animals, it appears as if many elements must have evolved simultaneously. Take bats, which have echolocation—they navigate by sound. To do that, many things must evolve. Bats need a specialized apparatus to make sounds, they need specialized ears to hear echoes, they need specialized brains to interpret the sounds, and they need specialized bodies to dive and swoop and catch insects. If all these things don’t evolve simultaneously, there’s no advantage. And to imagine all these things happen purely by chance is like imagining that a tornado can hit a junkyard and assemble the parts into a working 747 airplane. It’s very hard to believe.”
“Okay,” Thorne said. “I agree.”
“Next problem. Evolution doesn’t always act like a blind force should. Certain environmental niches don’t get filled. Certain plants don’t get eaten. And certain animals don’t evolve much. Sharks haven’t changed for a hundred and sixty million years. Opossums haven’t changed since dinosaurs became extinct, sixty-five million years ago. The environments for these animals have changed dramatically, but the animals have remained almost the same. Not exactly the same, but almost. In other words, it appears they haven’t responded to their environment.”
“Maybe they’re still well adapted,” Arby said.
“Maybe. Or maybe there’s something else going on that we don’t understand.”
“Like what?”
“Like other rules that influence the outcome.”
Thorne said, “Are you saying evolution is directed?”
“No,” Malcolm said. “That’s Creationism and it’s wrong. Just plain wrong. But I am saying that natural selection acting on genes is probably not the whole story. It’s too simple. Other forces are also at work. The hemoglobin molecule is a protein that is folded like a sandwich around a central iron atom that binds oxygen. Hemoglobin expands and contracts when it takes on and gives up oxygen—like a tiny molecular lung. Now, we know the sequence of amino acids that make up hemoglobin. But we don’t know how to fold it. Fortunately, we don’t need to know that, because if you make the molecule, it folds all by itself. It organizes itself. And it turns out, again and again, that living things seem to have a self-organizing
quality. Proteins fold. Enzymes interact. Cells arrange themselves to form organs and the organs arrange themselves to form a coherent individual. Individuals organize themselves to make a population. And populations organize themselves to make a coherent biosphere. From complexity theory, we’re starting to have a sense of how this self-organization may happen, and what it means. And it implies a major change in how we view evolution.”
“But,” Arby said, “in the end, evolution still must be the result of the environment acting on genes.”
“I don’t think it’s enough, Arb,” Malcolm said. “I think more is involved—I think there has to be more, even to explain how our own species arose.”
“About three million years ago,” Malcolm said, “some African apes that had been living in trees came down to the ground. There was nothing special about these apes. Their brains were small and they weren’t especially smart. They didn’t have claws or sharp teeth for weapons. They weren’t particularly strong, or fast. They were certainly no match for a leopard. But because they were short, they started standing upright on their hind legs, to see over the tall African grass. That’s how it began. Just some ordinary apes, looking out over the grass.
“As time went on, the apes stood upright more and more of the time. That left their hands free to do things. Like all apes, they were tool-users. Chimps, for example, use twigs to fish for termites. That sort of thing. As time went on, our ape ancestors developed more complex tools. That stimulated their brains to grow in size and complexity. It began a spiral: more complex tools provoked more complex brains which provoked more complex tools. And our brains literally exploded, in evolutionary terms. Our brains more than doubled in size in about a million years. And that caused problems for us.”
“Like what?”