Timeline

Ancient Era

 * 300,000-400,000 BCE: Wyrdos modify/terraform Mars and bring over flora and fauna from Earth. After establishing a stable Earth-like ecosystem, they bring over founder populations of proto-humans (Tharsians, Troglodytes, etc.). Following this, they erect the Pylons and unleash their Zombie virus to aid the experimental proto-human societies.
 * 200,000 BCE: By this time, life on Mars is practically extinct. There are no more proto-human societies, and the atmosphere is almost completely gone. It is unclear whether this was the result of planned Wyrdo action, a cataclysmic event, or a slow-acting natural progression. It is also unclear whether all the species brought over by the Wyrdos simply died out or whether they were taken elsewhere.

Modern Era

 * 2011 CE: Exploration of a desolate Mars begins with unmanned rovers. Rovers are government-funded.
 * 2023 CE: The first experimental human base on Mars is constructed thanks to the information gathered by rovers. Transportable modules are shipped to Mars with equipment to make use of available resources and to establish a permanent station. This is done as a collaborative effort between a few Earth governments and funding from private global corporations. First attempts at terraformation begin.
 * 2050 CE: Construction of the first Dome begins, with the aid of robots and a skeleton crew of people. The Dome is meant to be a permanent base of operations and research as terraformation continues.
 * 2050-2080 CE: Construction of the second and third Dome begins. These Domes are completely funded and run by corporations. Somewhere during this span, the robots begin to exhibit erratic behavior.
 * 2081 CE: First Dome is completely finished and is now 70% populated. People begin to move to Mars more steadily.
 * 2110 CE: Communication with Earth is lost for unknown reasons.