Evolution

As the world had emptied and been eroded flat, the lack of cover was the killer. In a landscape like a pool table, you just couldn’t hide a one-ton salamander, even if it was painted as red as the rocks. That was why most of the big animals had quickly disappeared, outcompeted by their smaller cousins.

But these creatures had adopted a novel strategy: the ultimate camouflage. The great redesign had taken many tens of millions of years.

Invisibility — or at least transparency — had been a strategy adopted by some fish in earlier times. There were transparent substitutes for most of the body’s biochemicals. A substitute had to be found for hemoglobin, for example, the bright red protein in blood cells that combined with oxygen to transport that vital substance through the body.

Of course no land-going creature could ever be truly invisible. Even in these arid times all animals were essentially bags of water. If you were actually immersed in water — where those long-extinct fish had once swum — something approaching true invisibility could be achieved. But light moved differently through air and water; in the air the final land-going "invisible" actually looked like a big bag of water sitting in the dirt.

Still, it worked pretty well. As long as you kept still you were hard to see — just a mistiness, a slight distortion here and there that might easily be mistaken for a bit of heat shimmer. You could huddle against a rocky outcrop, ensuring that you presented only your least visible angles to any prey. You even had fur, transparent-like fiber-optic cable, which transmitted bits of background color to baffle your prey further.

But even so, few species had adopted the stratagem, for invisibility was a blight.

Every invisible was blind, of course. No transparent retina could trap light. On top of that the creature’s biochemistry, limited by the use of transparent substances, was a lot less efficient. And there was no shielding, even for its innermost parts, from the ferocious light, heat, and ultraviolet radiation from the sun, or from the cosmic radiation that had always battered the planet despite its great shield of magnetism. Its organs were transparent, but not transparent enough to let through all the damaging radiation.

Already Cactus’s killer was in agony, and soon the cancers developing in its transparent gut would kill it. And it was neotenous. It would die without reaching puberty. None of the invisible kind had ever lived long enough to breed true, nor would their genetic material, damaged by radiation, ever have been able to produce a viable offspring.

Sickly, helpless from birth, these wretched creatures began dying before they emerged from their eggs.

But that didn’t matter, not from the point of view of the genes, for the family benefited.

This amphibian species had reached a compromise. Most of its young were born as they always had been. But perhaps one in ten was born invisible. Like the sterile workers in a hive, the invisible lived through its brief, painful life and died young, all for a single purpose: to retrieve food for its siblings. Through them — through their offspring, not its own — the invisible’s genetic legacy would live on.

It was an expensive strategy. But it was better to sacrifice one in ten of each generation to a brief life of agony than to succumb to extinction.

The presence of food in its stomach and waste in its lower gut made the invisible easy to spot, of course. So when they were hungry again its siblings would starve it, waiting for all the waste to pass out of its system, rendering it as transparent as possible. And then they would set it to work once more, under the lethal sun, hoping to have it snatch one more meal for them before it died.

The sphere had made its own observations of these events.

The sphere was a living thing, and yet it was not. It was an artifact — and yet it was not that either. The sphere had no name for itself, or for its kind. Yet it was conscious.

It was one of a great horde that now spanned the stars, in a great belt of colonization that swept around the Galaxy’s limb. And yet the sphere had come here, to this ruined world, seeking answers.

Memories stretched deep. Among the sphere’s kind, identity was a fluid thing, to be split and shared and passed on through components and blueprints. The sphere could think back, deep through thousands of generations, but it was a memory trail that ended in mist. The replicating hordes had forgotten where they came from.

In its way, the sphere longed to know. How had this great star-spanning swarm of robots first originated? Had there been some form of spontaneous mechanical emergence, cogs and circuits coming together on some metallic asteroid? Or had there been a Designer, some other, who had brought the progenitors of these swarming masses into being?