After the terrashaping and terraforming of Gaia in 10165 CE, other colonists hoped to terrashape other Earth sized worlds in order to create copies of Earth. With that, worlds nearby Earth were scouted as potential candidates for terrashaping. One of the most promising stars was HIP 88194, however none of the moons of its only parent planet were suitable for the then current abilities of the new terrashaping technology. However, in the year 10235 CE advancements in the technology allowed for the construction of an entirely brand new world. With this, the star was revisited and construction of a new world began in 10240 CE.
In essence, a large amount of HIP 88194's Kuiper Belt objects were removed and placed in a terrestrial orbit of HIP 88194. Utilizing powerful tractor beams and force field generation, the objects were squeezed around the largest iron object in the star system until a core was created.
With that, more objects, some of ice and others of rock and iron were thrown into orbit of the new core. For the next hundred years the inner and outer crust was formed, then the lithosphere. When the planet had reached Earth's own gravity and mass, the orbital carving lasers got to work carving every minute detail into the planet's surface, including tectonic plates. Construction of a Moon counterpart began at the same time.
When the minute details were completed (minus a few 'improvements' such as the recreation of Mt. Mazama and pre-eruption Mt. St. Helens) the terraforming process began with the importing of nitrogen and oxygen from one of HIP 88194b's nitrogen rich moons as well as the electrolysis of water from the excess ice comets. With the formation of the new atmosphere plant life was quickly introduced to the planet along with local animal life. By the year 10432 terraforming of the planet was complete. Humans established their first colony in the year 10450 in the African footprint.
The life forms on Tiamat are identical to those on Earth. Many different extinct species were also brought back, including many Ice Age life such as the Woolly Mammoth and Sabertooth tiger.
One life form that wasn't imported was the mosquito, which by this time had been all but made extinct.