"That's the way it looks."
"Oh, there's no question about it," Levine said. He sighed. "It's so agreeable to be proven right."
On the ground below, Eddie unpacked the circular aluminum cage, the same one they had seen in California. It was six feet tall and four feet in diameter, constructed of one-inch titanium bars. "What do you want me to do with this?" Eddie said.
"Leave it down there," Levine said. "That's where it belongs."
Eddie set the cage upright in the corner of the scaffolding. Levine climbed down.
"And what's that for?" Arby said, looking down. "Catching a dinosaur?"
In point of fact, just the opposite." Levine clipped the cage to the side of the scaffolding. He swung the door open and shut, testing it. There was a lock in the door. He checked the lock, too, leaving the key in place, with its dangling elastic loop. "It's a predator cage, like a shark " Levine said, "If you're down here walking around and anything happens, you can climb in here, and you'll be safe."
"In case what happens?" Arby said, with a worried look.
"Actually, I don't think anything will happen," Levine said. "Because I doubt the animals will pay any attention to us, or to this little house, once the structure's been concealed."
"You mean they won't see it?"
"Oh, they'll see it," Levine said, "but they'll ignore it."
"But if they smell us..."
Levine shook his head. "We sited the hide so the prevailing wind is toward us. And you may have noticed these ferns have a distinct smell." It was a mild, slightly tangy odor, almost like eucalyptus.
Arby fretted. "But suppose they decide to eat the ferns?"
"They won't," Levine said. "These are Dicranopterus cyatheoides. They're mildly toxic and cause a rash in the month. In point of fact, there's a theory that their toxicity first evolved back in the Jurassic, as a defense against dinosaur browsers."
"That's not a theory," Malcolm said. "It's just idle speculation."
"There's some logic behind it," Levine said. "Plant life in the Mesozoic must have been severely challenged by the arrival of very large dinosaurs. Herds of giant herbivores, each animal consuming hundreds of pounds of plant matter each day, would have wiped out any plants that didn't evolve some defense - a bad taste, or nettles, or thorns, or chemical toxicity. So perhaps cyatheoides evolved its toxicity back then. And it's very effective, because contemporary animals don't eat these ferns, anywhere on earth. That's why they're so abundant. You may have noticed."
"Plants have defenses?" Kelly said.
"Of course they do. Plants evolve like every other form of life, and they've come up with their own forms of aggression, defense, and so on. In the nineteenth century, most theories concerned animals - nature red in tooth and claw, all that. But now scientists are thinking about nature green in root and stem. We realize that plants, in their ceaseless struggle to survive, have evolved everything from complex symbiosis with other animals, to signaling mechanisms to warn other plants, to outright chemical warfare."
Kelly frowned. "Signaling? Like what?"
"Oh, there are many examples," Levine said. "In Africa acacia trees evolved very long, sharp thorns - three inches or so - but that only provoked animals like giraffes and antelope to evolve long tongues to get past the thorns. Thorns alone didn't work. So in the evolutionary arms race, the acacia trees next evolved toxicity. They started to produce large quantities of tannin in their leaves, which sets off a lethal metabolic reaction in the animals that eat them. Literally kills them. At the same time, the acacias also evolved a kind of chemical warning system among themselves. If an antelope begins to eat one tree in a grove, that tree releases the chemical ethylene into the air, which causes other trees in the grove to step up the production of leaf tannin. Within five or ten minutes, the other trees are producing more tannin, making themselves poisonous.
"And then what happens to the antelope? It dies?"
"Well, not any more," Levine said, "because the evolutionary arms race continued, Eventually, antelopes learned that they could only browse for a short time. Once the trees started to produce more tannin, they had to stop eating it. And the browsers developed new strategies. For example, when a giraffe eats an acacia tree, it then avoids all the trees downwind. Instead, it moves on to another tree that is some distance away. So the animals have adapted to this defense, too."
"In evolutionary theory, this is called the Red Queen phenomenon," Malcolm said. "Because in Alice in Wonderland the Red Queen tells Alice she has to run as fast as she can just to stay where she is. That's the way evolutionary spirals seem. All the organisms are evolving at a furious pace just to stay in the same balance. To stay where they are."
Arby said, "And this is common? Even with plants?"
"Oh yes," Levine said. "In their own way, plants are extremely active. Oak trees, for example, produce tannin and phenol as a defense when caterpillars attack them. A whole grove of trees is alerted as soon as one tree is infested. It's a way to protect the entire grove - a kind of cooperation among trees, you might say."
Arby nodded, and looked out from the high hide at the apatosaurs, still by the river below. "So," Arby said, "is that why the dinosaurs haven't eaten all the trees off this island? Because those big apatosaurs must eat a lot of plants. They have long necks to eat the high leaves. But the trees hardly look touched."