Polar Shift (NUMA Files 6)

Maria diplomatically deferred to her husband. "Sergei? As project director, what do you think?"

"I think that Ms. Janos has offered a solution that we can all live with."

"There's a quid pro quo," she said. "Maybe you can help me with my project."

"My apologies," Dr. Sato said. "We've been so self-absorbed with our own issues that we've become impolite. What exactly do you hope to find here?"

"An answer to the riddle of the mammoth."

"The Pleistocene extinction?" Maria said.

Karla nodded. "Picture this island twenty thousand years ago. The land outside our tent was green with vegetation. The earth shook with the thunder made by the feet of vast herds of Mammuthus. These creatures stood up to fourteen feet tall, making them the largest of all the elephants. Their great herds roamed the ancient world, going back more than three million years. They were in North America, from North Carolina to Alaska, in most of Russia and Europe, and even in Britain and Ireland. But by eight thousand B.C., they were nearly gone, except for remnants here and there. The herds of mammoths vanished, along with hundreds of other species, leaving their frozen bones to puzzle scientists like us."

"The extinction is one of the greatest mysteries in the world," Maria said. "Mammoths, mastodons, saber-toothed tigers-all disappeared from the face of the earth ten to twelve thousand years ago, along with nearly two hundred other species of large mammals. Millions of animals died on a global

scale. What do you hope to find here?"

"I'm not sure," Karla said. "As you know, there are three theories explaining the extinction. The first is that the Clovis people hunted them to extinction."

"The main problem with that theory is that it doesn't explain the extinction in the rest of the world," Arbatov said.

"There is also no fossil evidence to support this idea, so we move on to theory two, that a killer virus swept through the mammal populations of the world."

"So you think the virus theory is the most plausible?" Dr. Sato said.

"Yes and no. I'll get back to it after we discuss the third theory, drastic climate change. Near the end of the period, the weather changed suddenly. But that theory has a big hole in it. Creatures on a number of islands survived. They would have died out if the extinction were weather related."

"So if it wasn't overhunting, or a virus or climate change, what was it?" Sergei said.

"The argument has always boiled down to two schools of thought.

Catastrophism, which says that a single event or a series of events caused the extinction. And uniformism, which maintains that extinction happened over a long period of time, from a number of causes."

"Which are you, a catastrophist or a uniformist?" Arbatov said.

"Neither. No single theory fits all the facts. I think it is all of the above, with the extinction set in motion by a cataclysm or series of cataclysms. Tsunamis. Volcanic eruptions that produced killing clouds and gas, altering the pattern of vegetation."

"There's a hole in that theory too," Arbatov said. "The evidence suggests that extinction occurred over a period of hundreds or thousands of years."

"That wouldn't be a problem. My theory takes into account the discovery of vast numbers of mammoths found tumbled in a common grave, and explains why some of the creatures survived long after that. Evidence demonstrates that many were killed by sudden violence. But we also know that a few mammoth species were around when the Egyptians were building the Pyramids. The cataclysm weakened the mammoth herds to a point where disease and hunters could polish them off. The extinction of certain species had a ripple effect. The predators that preyed on the mammoths and other creatures would lose their food source."

"I think you're onto something, but you're saying that this worldwide cataclysm occurred suddenly. One minute, the mammoths were peacefully chewing on grass. The next, they were on their way to extinction. Isn't that far-fetched?"

"Not at all. But I would be the first to admit that the theory of polar shift is controversial."

"Polar shift?"

"A realignment of the poles."

"None of us is a geologist," Arbatov said. "Please explain."

"I'd be glad to. There are two types of polar shift. A 'magnetic polar shift' would involve a reversal of the magnetic poles, causing all sorts of unpleasantness but nothing we couldn't survive. A 'geologic polar shift' would mean actual movement of the earth's crust over its molten core. Something like that could create a cataclysm like the one I believe killed the mammoths as a species."

Arbatov was unconvinced. "You're basing your extinction theory on the theoretical shifting of the poles? You'll have to admit that it's unlikely that such a disruption could occur."

"On the contrary. It has happened, and could happen again."

Arbatov made a show of taking Karla's glass. "Our guest has had a little too much vodka."