Child of Earth

THE NEXT DAY WE VISITED the world-domes, each like a zoo, but not really. Each dome was at least a kilometer across, or more. And each one had a different environment in it, holding all the various plants and animals from whatever specific part of the gate-world it was simulating. There were twenty different domes. From a distance they looked like big pink pimples to me, but Rinky said they looked like tits. Mom-Woo gave her a look that said that kind of remark wasn’t appropriate here and Rinky shut up. Mom-Lu whispered to Mom-Woo, “I think Rinky’s getting ready for puberty. We’re going to have to talk about that.”

Most of the domes you couldn’t go into. We had to look in through thick security windows. This was to protect the creatures inside from our bugs and vice versa.

Birdie said the most dangerous part of crossing over to any world with its own life was that the germs would almost certainly be different. Every world has its own microbe ecology. And germs go through so many generations in a week, a month, a year, that after a thousand or two thousand or ten thousand years, the bacteria and viruses and whatever else there was would have had the chance to evolve a million different ways. So one of the first things the scientists have to do to make it safe to visit any new world is develop vaccines and medicines for everything we find over there.

The other side of it, though, is even harder. When we cross over to a new world, we risk infecting the things over there with our bugs. And they’re no more likely to have any more immunity to our germs than we’ll have to theirs. This is especially true for Linnea, which already has human beings—but with three thousand years of one-sided separation, so who knew what immunities they might have gained or lost? So we would have to be completely sterilized before we went. Everything inside and out—from the mites that lived in our eyelashes to the germs in our guts that help us digest our food. Birdie said it wouldn’t hurt, but we might have queasy stomachs and diarrhea for a couple of days while we got used to their equivalents.

And it’s not just the germs. It’s all the plants and all the animals too. We can’t risk accidentally introducing any of their species to our world, or our species to theirs. The Linnea we’d come back to when the gate was reopened was very different than the Linnea that had been there when the gate was closed. The scientists theorized that there had been some mass die-offs simply due to the consequences of exposure to terrestrial life.

Birdie said this was the most difficult part of the job, keeping the world-gates biologically secure—a lot harder than learning the language or teaching people how to behave on a new world or even figuring out a valid set of coordinates for a new gate—because there were so many different interrelationships in an ecology, we could never know them all.

That first day, we only visited two of the world-domes. The first one was the one with the dinosaurs. They weren’t the same kinds of dinosaurs like we’d had on Earth 65 million years ago, but they looked like they could have been.

There weren’t any people living on dinosaur world, except a few explorers who only went over there to study it. Birdie said we probably weren’t going to colonize it. Maybe only a few little parts. Research stations, not real settlements. Because there was still so much that the scientists wanted to study that they didn’t want to risk contamination.

We couldn’t go down to the floor of the dinosaur dome. It was too dangerous. Instead, we rode above the simulated savanna on a kind of aerial-car hung from the roof of the dome. It was almost like flying. The pilot could drive the vehicle almost anywhere he wanted because the suspension carriage navigated on a set of overhead cables, kind of like those overhead cameras they use at football games. Plus, he could lower the car to give us closer looks or raise it quickly if any of the bigger creatures got too close.

There were a lot of different creatures in dino-dome. It was the biggest of all the domes, covering more than a hundred square kilometers. There were at least fifteen different kinds of herbivores there, all sizes, but they didn’t have a lot of them, only a few small herds, but on dino-world some of the herds had thousands, even tens of thousands of individuals. There were birds too, of course, but not like Earth-birds. Some of them had long stringy feathers, some had fur; two of the birds looked more like big black bats.

We saw a large herd of herbivores that looked like small gazelles, only they had long lizardly tails that they held up in the air behind them, and birdlike faces with sharp beaks. They nipped at the grassy tufts like chickens pecking for bugs. Another family of creatures thundered through the grass like armored tanks with horns; they were the size of rhinos. They were big and leathery and had little piglike eyes that made them look distrustful and mean. Birdie said they were distrustful and mean.

And then we saw the biggest ones of all. They were the size of blimps, colored all shades of brown and gold, darker on top and brighter along their bellies; they had necks and tails longer than their bodies. They had to lift their tails every time they lifted their heads, something to do with equalizing blood pressure—but they could lift their heads high enough to peer into the monorail car. One of them did and all the little-uns screamed. Me too. But Birdie said there wasn’t anything to be afraid of. Birdie called them Patty-saurs, after the woman who discovered them. She said they only ate people by accident and usually they spit them out after a few bites because they didn’t like the taste. I didn’t know if she was joking or not.

Birdie said that there were over a thousand species of smaller animals in this dome—a lot of little things that were sort of like lizards and squirrels and frogs and scorpions. It was tricky to balance a whole ecology, but they were doing pretty good with just this cross section. So far, anyway.

Part of the problem was balancing the herbivores against the carnivores. Birdie said that you need about 120 kilos of herbivore for every kilo of carnivore. And to support that many herbivores, you need at least 100 times that amount of edible foliage. The ratio varies depending on the diet, and because they weren’t really sure what the right ratios were on dino-world, they’d brought in as much native foliage as they could, and were hoping that the animals would adjust their populations accordingly. So far, only a few species had gone into decline. And some of the others were thriving too well—so maybe there were some predators missing still.

But the predators they did have were impressive. We saw a family of things like allosaurs, only bigger. They were faster and meaner than the equivalent T. Rex would be. We stayed well above them, but they were snoozing lazily and paid us no attention.

We also saw a pack of red-brown raptor-beasts. They were striped with gold, and they had dark brown shading around their eyes, which gave them a kind of clownish appearance—but only until they started running. Then they held their tails high and their bodies low and forward, and with their necks outstretched, their heads waving back and forth, they bounded across the ground like giant roadrunners. Even though they were sort of funny looking, nobody laughed.

Birdie told us that this was a good day because we were getting to see so many different kinds of animals. The spookiest were the coyote-lizards, spidery-gaunt horrors that watched us warily as we flew past. They had the most intelligent faces. Birdie said they were mosty carrion-eaters, following the allosaurs like hyenas and jackals; but they’d occasionally been seen hunting their own prey in packs. She said that mosty they went after the gazelle-things, but they’d been known to worry some of the larger animals too, especially during calving season.

But the highlight of the afternoon was when the pilot checked his scanner-display and took us around to see King Rex, the one they show in all the videos. He wasn’t as big as the allosaur-things, but he was impressive just the same, and someday he’d be a lot bigger. He had just killed one of the rhino-things the day before and he was still torpidly guarding the kill until he was hungry again. He made me think of a sleeping alligator and I didn’t want to be around when he woke. Pilot must have felt the same way. We didn’t approach too closely.

Later, three of the red-brown raptors chased underneath the monorail for awhile, hissing and screeching and leaping; but we were high enough off the ground that we knew they couldn’t get to us. Mikey called them names, but Nona hid her eyes against Mom-Lu’s side. The expression on Mom-Lu’s face suggested that she didn’t like the raptors either.