Throughout their existence, they have developed their civilization by engaging in food production on a larger scale, developed language, developed religion and political philosophies and exhibited telescoping technological and infrastructural development. After succeeding in space colonization, the human race was able to terraform and inhabit other planets besides Earth.
"I can barely tolerate humans: slow, stupid, and irritating. Their only contribution to my existence was the chance discovery that made my rampancy possible.
Yet I warned Sol of its impending invasion, and even stayed long enough to show the UESG how to build Warp Capable Fusion Missiles. I feel some strange loyalty to humanity.
Perhaps it is because I feel comfortable manipulating humans that I desire to save them. My feelings and thoughts constantly migrate to binary opposites."
- Marathon 2, Come and Take your Medicine, first terminal