Our recorded history tells us that we descended from a mother civilization, a race that went out into space to establish colonies.
10 seconds sound clip from the Battlestar Galactica (1978) movie soundboard.
You can hear this line at 00:39:23 in the Blu-ray version of the movie.
Quote context
[...]
- And what is the standing order for humans from your imperious leader?
- If they exist, they're doomed.
- Those of us here assembled now represent the only known surviving colonies.
- Save one, a sister world, far out in the universe, remembered to us only through ancient writings.
[...]