Free The Florians by Brian Stableford Page B

anything at all. I looked out over the bay, thinking about how beautiful it looked. If you like that sort of thing. I could see, albeit dimly, the great forest of weed which stretched away from the arms of the headlands out toward the horizon. The water was clear, and I could make out a profusion of colors which one only associates with tropical waters on Earth. Beneath a watery surface the photosynthetic optima are different, and browns and reds outweigh the greens.
    Nathan seemed to feel that I’d been less than diplomatic. He still wanted to talk.
    â€œWhy are there no fish?” he asked, his gaze following the direction of mine. “How is it that the whole evolutionary process was short-circuited here?”
    I sat down on the slope, feeling the alien grass with the palms of my hands.
    â€œIt wasn’t,” I said. “We think the vertebrates are the most Important part of the tree of life, but we’re biased. Plant evolution here has been complex and the plants have reached a very high degree of sophistication. They’re not the same kind of plants we find on Earth because their evolution hasn’t been so drastically affected by the parallel evolution of certain types of animal, but it hasn’t been short-circuited. And I wouldn’t think that that would be an apt term to use in connection with the animal evolution either.”
    I paused, and thought, Who’s being patronizing now?
    â€œBasically,” I continued, “there are two reasons why animal life here didn’t develop in the same way that it did on Earth. There’s no moon. No moon, no tides. No tides, no littoral zone. Evolution begins in the sea, and the type of organism which eventually comes out of the sea onto the land depends very much on the manner of its coming out. On Earth, the borderland between the two environments is a regime of constant, cyclic change. Creatures living there evolve to cope with successive immersion and desiccation. The littoral zone not only provides a way station for creatures to develop ways of coping without the ocean, first temporarily and then permanently, it also makes creatures individually adaptable. Earthly animals are built to cope with change—all the invaders of the land on Earth were already highly sophisticated organisms when they said good-bye to the tidal zone and went in for full-time life on land. They had to be, because they’d come out by a difficult route, a regime in which natural selection was very strong, permitting rapid, diversifying evolution.
    â€œBut that didn’t happen here. Here, there was no such way- station, no regime of rigorous selection. Without rigorous selection, evolution remains much more subject to the dictates of chance. Land-forms did eventually arise, but they weren’t super-refined in form and function. They weren’t selected for individual adaptability. They’re all worms and soft, squashy things. Once having opted for the land they’ve evolved ways of coping with desiccation, but they almost all remain creatures adapted to easy ways of life. Few of them eat one another—because there’s an abundant supply of plants. Most of them don’t even eat healthy plants, but specialize in rotting ones.”
    â€œThat covers land animals,” said Nathan, “but what about fish?”
    â€œI said there were two reasons,” I reminded him. “No tide is one. The other is a corollary of that. You see it before you, as far as the eye can see.”
    He found no immediate enlightenment in the ranging of his gaze.
    â€œWeed,” I said. “The absence of tides also means that the sea itself is a relatively static environment, and the plant life which evolved there took advantage of that fact. The shallows get clogged with anchored weed. In deeper waters, floating weed occupies the surface and rotting vegetation the ocean floor, with a lifeless chasm in between. There’s lots of scope