[quote=marcopolonian]I see. How often should castaways be created? Only when the entity desires it? Or accidentally and every so often? (or somewhere in between the two?)An unrelated question: has an ozone layer already formed on this planet? How safe is the surface?[/quote]

Castaway species will split off naturally, but because we're still starting out here, we haven't had a chance to create very many. You can also create them yourself with any major split in your group.

[quote=Kyelin]I'm thinking that, as the entities progress, they abandon their older creations for more recent ones. And so, the older taxons become free game, for those who don't want to start from scratch and experiment a little. We only have so much Sphere Space, after all.[/quote]

This too.

As for ozone... As usual, we're assuming that cyanobacteria and stuff has been present and pumping out oxygen for a considerable amount of time now (lack of oxygen certainly hasn't bothered our amoebas yet, although that's underwater). I'd guess that the surface is habitable for appropriately protected species, and will only become more so the more photosynthesis we get running up there.