Because of the pettiness of human concerns, and the deceptive drama of truly insignificant events (wars, assassinations, famines, the failure of colonies and the rest of human jiggling and jumping), it is easy for the author of a history of the Lab to lose sight of a truth, and a question, more important than anything else he has to say. Human explorers came out here in 2253 and found what? Two hundred earth-like planets in fifty adjoining systems. Perfect, beautiful worlds with oxygen atmospheres ready for breathing, soil ready for plants, and no life whatever.
How do you explain a perfect oxygen planet with no life? No plants to generate the oxygen and absorb the CO2, no animals to die and fertilize the soil for future generations of plants? Exactly four of them, in orbits impossibly close to one another, in most of the systems? A general lack (with a few exceptions) of other kinds of planetary objects--gas giants, molten midgets, asteroids, or dead planets like Mars? If it weren't for the variations-- systems with three earth-like worlds or five, a few systems with anomalous extra planets which aren't earth-like--the conviction would be overwhelming that the Lab was artificial. Row upon row of neat planters waiting for seed. The missing worlds and the extra ones were enough to set the scientists off--and they have been at it, inconclusively, five hundred years--looking for explanations of how the Lab happened rather than was made.
There have always been cults--they spring into being and die again like small brushfires in the far corners of a huge field-- which hold that the Lab was created by a god-like alien species, for humanity's benefit or for some other sacred purpose. Who left it as a gift for us. Since I am secular-- I do not believe in gods or gifts-- I prefer to believe the Lab, if made, was made by aliens. By which I mean natural beings governed by regular physical laws, not gods. Who made the Lab to live in themselves, or for some other mysterious purpose of their own. The problem is they left no archaeological trace whatever. There are no fossils of the Lab's creators or of their "clients" or pets. No old space junk which would let us know that anyone else has been this way. Just two hundred pristine, empty planets in fifty systems.
Sometimes I have imagined the creators returning and discovering their "summer" home (which they have not visited since last "season", ten thousand years ago) infested by human mice. Anyone who could make the Lab could clean us out of it in a day. I always end by hoping it doesn't happen in my lifetime. After me, they can do whatever the fuck they want. I don't really mean that; Gabriel may still be here, and Jessica certainly will.
When humans first got here, there were many religious folk who wrote beautiful treatises about the Lab as proof of God's existence. I particularly remember a Catholic tome, an Islamic text and a particularly ornate, Talmudic essay by a rabbi from Brooklyn. They make beautiful reading, not so much for the persuasiveness of the arguments, but the thrilling quality of the language. They were written by men and women who loved what they saw and mistakenly saw their own love as proof of a deity.
What has happened since is the standard human process. Not only is much of the beauty gone, on the larger, more industrial worlds, but over time we have come to take for granted what remains. If you live within a miracle, after a while it is just your home.