Human

Humans are a species of intelligent life that originated on Earth. There are currently around 1 trillion humans living on Tetro, approximately half of which reside in the Lost Colony.

Physical Characteristics
Humans have a central torso, which contains the major organs. A head containing the brain and sensory organs protrudes from the top of the torso, connected by a short neck. The torso is supported from beneath by two single-jointed legs ending in feet. Two single-jointed arms (primary manipulative appendages) are connected to the top of the torso, one on either side.

History of Humans on Tetro
After the Discovery of Earth by a Tetrian space expedition in the year 1432, various Tetrian organizations considered the possibility of transporting humans and other species from Earth to Tetro for scientific research. The Dramilian Federation's leaders realized that an influx of new species to Tetro could potentially destabilize the planet's ecosystems, or worse, lead to a change in the balance of power between the Dramilian Federation and its economic rivals. As a result, the Federation published a document which detailed potential risks of introducing Earth species to Tetro. Among a long list of highly exaggerated dangers was the claim that based on analysis of data collected from Earth thus far, it was possible that diseases from Earth could wipe out all life on Tetro. It wasn't long before all research missions to Earth ceased. Having successfully eliminated any potential competition, the Dramilian Federation secretly began to conduct feasibility studies into relocating Humans to Tetro. By 1446, the Federation had established the following guidelines for future contact with Earth:
 * Any object or person which has entered Earth's atmosphere must be sterilized by heat, cold, vacuum, and radiation before it can enter Tetro's atmosphere.
 * It is forbidden to interfere with Human affairs. Tetrians visiting Earth may not communicate with Humans or allow any evidence of their existence to be detected by Humans.
 * All Federation missions to Earth must be covert. Any person involved in such a mission must not allow any evidence of the mission to be detected by any person not involved in the mission.
 * Any life form transported to Tetro from Earth must be unable to reproduce.
 * Any life form transported to Tetro from Earth must be contained in a secure research facility within Dramilia Central.
 * Only one species at a time may be transported to Tetro from Earth for research. Each species must be subjected to an array of tests to determine the risks it poses to Tetro. After a species has passed all such tests without a single risk identified, another species may be selected for research and transported to Tetro. If a risk is identified in any such test, all individuals of that species present on Tetro must be returned to Earth immediately and no individuals of that species may ever be transported to Tetro again.

For the next hundred Earth-years, the Dramilian Federation conducted thousands of research missions to Earth while adhering strictly to these guidelines. Initially these missions were focused on installing surveillance outposts all across the planet to collect data on geology, weather, and the language and behavior of Earth's species.

Humans were selected as the first species to be transported to Tetro. However, there were two problems which needed to be addressed before a single Human could set foot on Tetro: first, a Human could not survive the sterilization process required by the guidelines, and second, it was not yet known how to prevent a Human from reproducing. To solve these problems, the Human genome needed to be mapped. This could only be accomplished by setting up a genetics laboratory on Earth since DNA samples could not survive sterilization. A remote location was needed for the lab to eliminate the possibility of humans stumbling across it, so an ice-plain near the North Pole was selected for this purpose. Once the genome was sequenced and transmitted back to Tetro, Federation scientists created an Earth-life development simulation that could determine an organism's phenotype based on any given DNA sequence. This allowed them to engineer new genes in order to solve the problems preventing Humans from being researched on Tetro. The first modified DNA that was engineered by Federation scientists added several features to the Human phenotype:
 * The ability to enter a dormant state upon being subjected to extreme temperatures, or when deprived of food, water, or oxygen
 * Skin which reflects and diffuses heat, and which is infused with a fine carbon mesh that resists punctures and cuts
 * Faster and more accurate repair of damaged DNA
 * The ability to regenerate damaged or missing tissue of any type
 * The inability to produce gametes

In order to insert the new genes into the DNA of living Humans, a virus was created which could infect all cells of a target Human and swap out specific genes with engineered replacements. By 1534, the Dramilian Federation was confident that its DNA-replacement process would allow any Human to be safely transported to Tetro. The Earth-contact safety guidelines were revised, allowing interference in Human affairs as long as no more that 2,187 Humans living on Earth had knowledge of such interference, and the natural course of Human history was not altered. Now it was just a matter of selecting which Humans would be transported. The Dramilian Federation spent years waiting for the right opportunity to present itself, as the guidelines severely limited the circumstances under which the relocation could occur. Any Humans taken had to be part of a small, isolated group, so that if anything went wrong, the news of Tetrian contact could not spread.

On Earth in the year 1587, a group of 115 Humans traveled from England to Roanoke Island near the East coast of North America, with the intention of establishing a permanent English colony at the site. Towards the end of the year, the colony's governor, John White, sailed to England for more supplies. He expected to return within a few months, but upon arrival in England he found that a war had begun with Spain and all ships were forced into naval service. This prevented his return to the colony for the next three years. Meanwhile, on Roanoke Island, a severe drought in the spring and summer of 1588 reduced crop yields to below what was needed to sustain the colony. At last, this was the opportunity that the Federation had been waiting for. The colonists had no contact with other Humans and it was probable that they would die unless rescued, so removing them from their home planet would be unlikely to alter Human history.

In August of 1588, all 116 Human colonists were transported from Earth to Tetro by a delegation from the Dramilian Federation's Expansionism Sector in what became known as the Roanoke Resettlement. It is unclear whether these humans left their homes willingly, since the details of the operation have been withheld by the Dramilian Federation. Prevailing theories suggest that the humans were likely interrogated and subjected to medical experiments until their death by natural or unnatural causes.