The Light of Greenbelt's Star

Greenbelt is a planet in the Borderspace region that has interchangeably been called Xenobiologist Paradise and Xenobiologist Hell. The planet is tidally locked to its star, but is large enough to maintain an atmosphere and orbits at a distance that allows liquid water to persist in many places on its surface. Its name comes from a broad band of planet that extends 300 or so kilometers on either side of the day-night terminator which supports a rich variety of green plant life. Analogues of grasses, trees, and shrubs exist, with the grasslike plants predominating on the day side and trees on the night side. Numerous animal life forms also thrive in this area. More exotic forms of both flora and fauna exist further away from the terminator on both day and night sides, but life density falls off rapidly with distance from the terminator.

Transformative Creatures

Several Greenbelt species, including representatives of both plant and animal, exhibit lifecycles that potentially include a significant metamorphosis of some form. Most notable of these are the Nibbler/Shredder, and the plant known as Greenbelt Grass. This plant appears as a short, fine-leaved grass on the day side, but grows into a taller, stalk-like form resembling Terran maize plants if the seed germinate on the night side of the terminator. In this form, these plants have even been known to demonstrate the ability to ambulate, pulling their root structures up to the surface and undulating them in a manner reminiscent of a Terran octopus traveling along a reef, then "digging in" at some new location. DNA analysis confirms that both plants are indeed the same species.

The Metamorphosis Trigger

The trigger behind these two notable transformations, and indeed behind every metamorphosis or dual developmental manifestation on Greenbelt has been traced to a single trigger: the presence or absence of the light of the planet's sun. This star is an unremarkable G-type yellow main sequence star quite similar to Terra's Sol - a fact that makes Greenbelt even more appealing as a potentially human-habitable world.

Apparently, though, at some point far in the past of the planet's evolutionary history, a photosensitive gene developed that reacts to the presence or absense of a particular narrow band of near-ultraviolet radiation. Specifically, this gene, which is normally "switched on" all the time, "switches off" in the presence of light radiation of 275-300 nanometers wavelength, and once switched off, will never switch back on.

This gene has been found to be present in every species of Greenbelt plant or animal examined thus far. Many species seem to have evolved to ignore the effects of this gene, but as mentioned, other species have life-cycles that are significantly affected by its initial state and whether or not it changes state during their lifetimes.

In the case of Greenbelt Grass, every germinating seed begins in the same manner, but as soon as the young plant breaks the soil surface, its metabolism - and future development lock into one plant form or the other depending on whether daylight reaches the plant.

In the aforementioned animal case, all of the creatures are born as Nibblers. Those that never travel across the terminator, or avoid rolling or falling into a dark hole or cavern, remain so all their lives. Within an hour of being deprived of sunlight, however, they transform into their Shredder form and remain in this form for the duration of their lives.