The Preservers were a super-race that operated in the Alpha Quadrant prior to rise of the current interstellar governments that occupy the region. Commander Spock of the Constitution-class USS Enterprise (NCC-1701) stated that "They passed through the galaxy rescuing primitive cultures which were in danger of extinction and seeding them, so to speak, where they could live and grow."
Among the cultures they transplanted were several of the more advanced and peaceful tribes of Native American tribes from Earth, who were transplanted to Amerind, a planet nearly half-a-galaxy away. Navajo, Mohican, and Delaware were represented. To these Humans, primitive compared to the Federation, the Preservers were known as ""the Wise Ones". The planet also contained plant species identical to those of Earth, which were extremely unlikely to have evolved there. They also provided this planet with a powerful obelisk-like asteroid deflector, and instructed the appointed medicine chief in its operation, to be transmitted from father to son.
Based on the complexity of the obelisk they appeared to have possessed extremely sophisticated building apparatus, consistent with a culture equal or surpassing that of the Federation during the 23rd century. They also possessed a highly advanced form of cipher writing, apparently based on musical scales.
Starfleet first became aware of the Preservers in 2268, when the USS Enterprise visited Amerind, and discovered the transplanted Native Americans as well as the obelisk. While the structure initially defied analysis, Commander Spock eventually deciphered the writing, from which he learned about the preservers. A Preserver obelisk was also present on one of the moons of Andoria.
The Preservers were thought to be active between 38,000 BCE to 18,000 BCE. The period was known as the Preserver Era, and was a relatively quiet period of galactic history, with only a handful of technologically advanced civilizations around, most planet-bound. If the Preservers had a significant empire, then it met with no opposition.
It was also theorized that the Preservers also seeded 892-IV, or Magna Roma, with Earth Romans, who established a parallel Roman Empire which lasted at least 20 centuries. Despite these suspected involvements with the Preservers, there was very little evidence of their true identities although a Preserver space buoy was analyzed at Starbase 25 in the 23rd century.
There was much controversy over the existence and actions of the Preservers. Critics of the theory argued that the preservation efforts that were documented were similar to the colonization as well as the spread of many space-going civilizations. They believed that the myth of the Preservers were actually the efforts and accomplishments of dozens of unrelated extinct cultures. These critics thus did not believe that all their actions were attributable to a single all-encompassing civilization.
Proponents, however, pointed out the existence of the Preserver obelisks as proof that a single culture was responsible for the seedings of various planets in the galaxy. But critics were quick to point out that other races may have duplicated the construction of the obelisk and that they served as a universal cultural talisman for the efforts made in preservation.
The Preserver hoax was a scandalous incident in the 23rd century in which three non-related but friendly Orion families sold counterfeit Preserver artifacts and documents to gullible Federation historians. They made a small fortune, while several reputations were shattered. The fallout from the scandal continues to color xenoarchaeological studies of the Preservers into the late 24th century.
After the discovery of the Progenitors some theorized that they and the Preservers were the same entities, however this theory is generally dismissed as the Progenitor society flourished 4.5 billion years ago, orders of magnitude farther back in time than the time of the Preservers, mere tens of thousands of years ago.