"Yes. At least, that's what scientists like Sarah Harding call it."
Thorne climbed up to join them. The little shelter was now quite crowded, but Levine didn't seem to notice. He was entirely focused on the dinosaurs; he turned a pair of binoculars on the animals spread across the plain. "Just as we thought," he said to Malcolm. "Spatial oranization. Infants and juveniles in the center of the herd, protective adults on the periphery. The apatosaurs use their tails as defense,"
"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?"