Reincarnations

WORLDS ENOUGH, AND TIME

I’ve been interested in ecological invasions and in what people call the Cambrian explosion for a long time. This little piece originally appeared as a "Probability Zero" in Analog. Zero? I don’t know. Have you got a better explanation?

So Many Worlds, So Little Time, said the slightly scorched sticker on the side of the starship

This one had an oxygen atmosphere, but not much else going for it. The oxygen meant there were plants in the seas. The ship’s database said those seas held animals, too: wormy things crawling on the mud, maybe digging into it; blobby things floating in the water. That was about it.

On land? Nothing. Zero. Zip. Zilch. Bare rock. The chewed-up bare rock that’s called dirt. No trees. No flowers. No grass. No ferny things. No mossy things, even. No nothing. Certainly nothing scurrying over the ground or buzzing through the air.

Sometimes planets like this had a stark beauty. The father liked such worlds, which was why they’d stopped at this one. But he’d flitted here, and he’d flitted there, and he had to say he was disappointed.

The mother wasn’t. She hadn’t much wanted to come here in the first place. But they’d been married a long time. If you expected him to give a little, you had to do the same.

They stood side by side, watching the ocean lap against a tropical-but bare, utterly bare-beach. He sighed. "I’ve seen about enough," he said. "It… just isn’t quite what I hoped for."

Told you so. But she didn’t say it. They had been married a long time. All she said was, "I wouldn’t mind seeing something different."

"We’ll do that, then," he said.

He was just turning back toward the ship when the kids swarmed down the ladder and ran toward him. That was a prodigy of sorts. The kids cared more about their games and the aquarium than about seeing what they thought of as a dull old planet. Well, by now he thought of it the same way, which was the problem.

"What’s up?" he asked.

"Aquarium’s in trouble," the girl said.

"Environmental unit crapped out," the boy agreed. He’d head off to the university after they got home. Where did time go?

"Well, plug in the replacement," the father said. They both looked shamefaced. "We forgot to pack one," the girl said.

"Oh, dear," the mother said.

"Without an environmental unit, everything’ll die." By the way the boy looked at the father, it was somehow his fault.

"I like the critters in there. I really like them." The girl sounded heartbroken.

"I don’t know what to tell you." The father knew damn well it wasn’t his fault.

The girl pointed toward the sea that seemed to stretch forever. "Could we… give them a chance, anyway? Not just watch them die?"

"It’s against the rules," the father said doubtfully.

"Please!" the kids chorused.

"I’ll never tell," the mother added. "Who’s to know?" "Well…" He thought a minute, then shrugged. "Okay- go ahead. But keep your mouths shut after we get home, you hear?"

"You’re the greatest, Dad!" the boy said. He and the girl ran back toward the ship.

Jack Conway fired up his Mac and started the Power-Point presentation. A projector put one weird creature after another up on the big screen. "This is a trilobite-an early arthropod. Some of you probably recognize it," Jack told his class. "This is Selkirkia, a priapulid worm. It lived in the mud, as they still do…This is Aysheia, a lobopod. Looks something like a worm and something like a bug, doesn’t it?.. Hallucigenia- great name-is probably another lobopod, with protective spines… Canadia is an annelid, related to earthworms… And this little fishy thing with eyestalks or antennae or whatever they are is Pikaia, an early chordate- -somebody from our own phylum."

He paused. "Nobody quite knows why there was such an explosion of metazoan body plans at the beginning of the Cambrian, 543 million years ago. Some of the more interesting theories include…"