The business name is simply that, a name, a way to identify a business, entity, or individual. Due to the potential value of a trademark and the inherent property rights entailed within a trademark, the application for a trademark is much more complicated.
These are two separate questions. Organisms do not serve evolutionary purposes. Traits within organisms affect their survival, which might be thought of as evolutionary purpose. Even that is still not quite right. This question might better ask for ecological purpose. Ants have many such purposes. They clean up dead organisms as scavengers.
Nitrogen Fixation. Like any other garden, the ant's fungus garden needs nitrogen in an available form fit to be used by the microorganisms. Research has showed that the fungus garden in the ants' nest fixes nitrogen. This means that the fungus is taking atmospheric nitrogen and reducing the nitrogen to produce ammonium.