The Dalriada are a group of homo sapiens native to this region of the Alpha Quadrant.  The Federation does not know how they got here, although biological evidence collected from those who have visited Starbase OMEGA indicates they are indeed homo sapiens, and therefore probably came from Earth at some point in the past.

These humans founded the Star Kingdom of Dalriada and built around the core of its constitutional monarchy and alliance of many systems.

There are many in the pro-Federation faction of the Dalriada that have been trading with the Federation settlers for several decades.  There is even a fairly large amount of Dalriadan merchant traffic in the Terebellum (SB OMEGA) system.  Others, however, see the Federation as a threat to Dalridan dominance in the region.