The Iahi Daon Colonial Empire became extinct 7,233,000 years before present; the name is a misnomer, because there is no evidence that the generation ships launched by this species ever successfully established any colonies. It is, of course, possible that any colonies that were established have been eradicated by unknown agents, as suggested by the Restorer Hypothesis; but apart from some intriguing remains on Estis III, there is no evidence for such a supposition.
Several Iahi Daon generation ships have been found in a derelict state since the Second Federation era. However the homeworld was not discovered until 9986 AT.
Although gross miscalculation is a possibility, it is probable that the Iahi Daon felt an urgent need to spread their population to other worlds. The reason, however, is unknown, as their homeworld shows no signs of heavy attack; perhaps plague, internal strife or another factor provoked the attempts to colonise. The Iahi Daon abandoned their technological society after approximately three hundred years, and slowly degenerated; their eventual extinction 600,000 years later appears to have been due to a natural environmental process.
Reconstruction of Y300 Iahi Daon Colonial Transport
Iahi Daon Colonial Transports were of the 'Generation Ship' model, massive hulls with with 'perpetual' artificial ecosystems and stable populations. Apparently the Iahi Daon believed that their ships could survive journeys of ten thousand years or more, since their propulsion systems were only capable of a small fraction of light speed. They seem to have had very good Closed Ecological Life Support technology on board their ships, and even after seven million years some of the ships still retain traces of microbial life, enough to give an insight into the original biology of their home world.
Two ships have been found in interstellar space (they are difficult to detect, and difficult to intercept in flight). Four others have been found derelict in planetary systems, two of which have been cleared out by unknown raiders millions of years in the past.
The Iahi Daon homeworld at Alpha Jupkai is currently located in the Carina Rush region, more than six thousand light years from Earth.
Because of the rotation of the galaxy, and the different proper motions of the stars, the Iahi Daon homeworld has migrated into the Terragen Sphere from outside, as have the several generation ships discovered so far. Some, or many, more such ships may be found outside the current Terragen Sphere as exploration continues.
Impact on Earth's evolution: 0 (No evidence that territory extended to Sol System)
All images by Aaron Hamilton except image 1 by Ron Bennett