Turn on completed and turn off researchable and unresearchable.
Ah, thank you pd. I think i get it now.
At first i thought there was too much redundant information unnecessarily complicating things. Why not have two options "completed" and "uncompleted" and be done with. As i see now "researchable" and "unresearchable" fall under "uncompleted".
Some more observations i made:
1. Swamps and tundras colonized after "Habitation Domes" constantly lose population.
2. One small tundra was lost due to famine while others seem to keep a minimum population.
I've seen it in other games: why not a delete option under the "save game" menu. Or a "save/delete game" option.
On 1&2 caused by low health.