Biomes are environments within the game which decide how evolution and population works in a set area. Each biome is geographically, climatically, and otherwise conditionally different in some way from all other biomes . Biomes contain a set amount of slots for organisms , and these slots each have conditions that must be filled. Organism slots in biomes do not have to all be filled for the biome to work. However, each one of these slots, or "niches" can be competed over. Evolving organisms depend on competing for slots.