Preemption of the Galaxy by the first advanced civilization.

The progress of intelligent life in the Galaxy is discussed in terms of life's propensity to inhabit every suitable niche, and consideration is given to the human role. It is shown that an advanced civilization could communicate either by radio, interstellar probe, or by other means than have yet to be identified. However, contact has not been observed, except for human efforts. Furthermore, terrestrial history demonstrates that the advent of one tool-capable and traveling population results in that species' expansion to all viable territories. The spread of the population occurs in much shorter time than does the evolution of the species, indicating that, perhaps, humans are the first intelligent species in the Galaxy, and may be the future population of the Galaxy.