It was uncovered in Canadian forest. Well it used to be a forest until the new owner decided that farmland was more valuable and raising temperatures made this possible. When an earth mover rolled over an innocuous rock and it broke open setting the little germ free.
At one time this colony had spread over the entire Earth. She was hot and young back them. Molten seas weren’t unusual and the radioactivity that would drive her core for billions of years was near the surface. Earth was a very lethal place back then to any life forms that walked on her today.
It was in this environment that a small bacteria would crash land. Castoff from a rocky collision in space. Life born during the birth of another solar system far away. The bacteria had traveled millennia between stars in cold hard vacuum. And then flaming entry into the thin poisonous atmosphere.
This bacteria was unlike anything alive today. Hardy to an extreme, a lifespan longer than most human civilizations, and an affinity for an energy source not commonly available in Earth’s mature verdant state when the rock was crushed by the earth moving machine.
For this bacteria liked radiation. Loved it really. Though it could subsist on the metallic results of radioactivity’s ladder towards entropy, it thrived on the hot, fast particles spun off from unstable atoms like a plant in direct sunlight.
Within centuries of it’s arrival on Earth it was the dominant life form. Stretching across the whole surface of the globe. One big colony of one bacteria. It was in the rocks, the air, and around the lava pools.
This lasted for some time until Earth was a bit less young and significantly cooler. The radiation dissipated leaving the results. Transmutation had turned light elements heavier. The bacteria was reduced to extracting energy from these rocks. Some colonies migrated with the cooling rock to remain next to the heat far down where rock becomes liquid.
On the surface the colony was no longer thriving. It was surviving.
One day a new trick was learned. That of taking energy from the very plentiful, but very unenergetic light particles coming from the green sun around which the Earth moves. This new trick differentiated the two bacteria. One event in a long line leading to a broken rock and an earth moving machine. Where one line was surviving, the new line thrived.
Thus, the dominant form of life was relegated to odd corners of the planet. Places where it could obtain the heat and radiation it was best suited for. Even in those corners it would learn new tricks that better suited it to that corner. It would slowly forget how to take energy from decaying of atoms and become better at manipulating the chemical properties of elements to pick up an electron or two.
The rock that broke open was unique. It contained the last colony of the original space-faring variety.
Normally, this event, the breaking open of a rock, would have gone unnoticed. Competition would have limited and likely killed the last specimen. An untold number of microorganisms are born and die every day unnoticed by those capable of reading this story. And on many other planets in many other solar systems that this bacteria seeded that is exactly what did happen.
However, Earth was different from those worlds. And that is the story.