Dominancy

Not to be confused with Ownership in the case of a sole being owning an object like a planet

A dominant specie is one which has control over it's home planet although, on a grander scale, it can also refer to the IG who run the intergalactic space along with it's associated galaxies.

Among the galaxies, there have been numerous situations of species who couldn't gain full control over their planet due to extraterrestrial interference or due to them being overpowered by other species that evolved on that planet alongside them and so, they are unable to gain the dominant status which they desire.