Population growth: How exactly does it work?

[Parasite]

It is calculated separately for each race on the planet and applied to that race. It is also rounded up. Therefore in a growing population, one popwill take one turn to become two people.

An interesting method is to put 4 different races on one colony ship. The turn they land they reproduce into 8 people. They start getting the 20 person bonus in 5 turns, not 16. It can get even better on a planet with two moons. Keep each moon population at 4 (or one for each race you control). Every few turns move them to the main planet and you get at least 12 people per turn. Even more when the main planet's pop gets high enough to make more than two of each.