Precursors

The significant number of terrestrial worlds with free oxygen atmospheres populating the galaxy had been well-established by the time the first ships made their way out of the solar system. Many theories had been written to explain the unexpected bounty of potentially life-bearing planets in the galaxy, but it was not until the first extrasolar missions in the latter half of the 21st century that the true explanation became clear.

The discovery of a number of artifacts and structures of great age and nonhuman manufacture was clear proof that humanity was not – or at least had not – been the only intelligent race to spread across the stars. Additionally, examination of the geology and fossil records of local worlds soon showed that the majority had actually been ‘seeded’ in the distant past, with complex ecosystems and often entire biospheres appearing practically overnight. It was not a leap to correlate the two.

Now, more than a century later, Precursor worlds have been found as far as robotic probes have ventured. Combined with the age of the bioforming which ranges from 100 to 120 million years before present and the resulting stellar drift over such a vast span of time, it is clear that Precursor influence was on the galactic scale.

Unfortunately, despite the number of worlds found and the archeology done over the past century, there is still little known about the Precursors themselves. Few clues remain about their biology beyond the fact that they were oxygen-breathers and essentially nothing is known regarding intangibles such philosophy, politics and religion. It is unknown to what extent the Precursors inhabited the worlds they bioformed; Precursor artifacts in the form of relic Delta Dust point to significant works on these worlds, but a hundred million years is a great deal of time to eliminate the traces left by a planetary civilization, no matter how advanced.

It is believed that the Precursors were deliberately spreading biodiversity throughout the galaxy, as many of the transplanted biospheres have distinctly different biochemical lineages. This theory became particularly accepted after the discovery of Zoo, a world derived from middle-Cretaceous flora and fauna. Since then, several more worlds with life of Earth origin have been found, though none are nearly as spectacular as Zoo. The Precursors appeared to have avoided long-term contact worlds with naturally evolved life; the Solar System of course has no Precursor relics or hints of visitation, but worlds such as Asakura and Van Lang which have rich, natural biospheres share the same pattern.

Not all Precursor worlds retain fully viable biospheres; it is estimated that half of those known to have been bioformed suffered partial or total biosphere collapse following the eventual disappearance of the Precursors. Erebus is a good example, as it appears to have been formed with a marginal biosphere to begin with and slid into a ‘snowball world’ environment approximately 70 million years ago. Likewise, continental drift put sufficient pressure on Otome’s biosphere to cause it to effectively collapse.