One thing I will be putting into StarCluster 3 is the concept of Homeworld Edges. This would simulate the fact that world conditions should have an impact on the characters as they grow up. A world with dim sunlight might have people with better night vision, or people on a planet with heavy gravity may be stronger. This is not necessarily evolutionary - 500 years is not always long enough to fix these traits well - but may be at least partially a product of genetic engineering.
The key is the World Conditions chosen when the world was created. As part of the world creation process, you choose Conditions to describe that world. Where conditions should give an Edge, a character from that homeworld should have that Edge. I will be limiting such Homeworld Edges to a max of one - if a player creates homeworld Conditions for his character that logically give three Edges, the PC would only be able to choose one of those three for his PC.