When Daniel MacLeod was small, his birthparents were smugglers. Not the kind of smugglers who make money with illicit drugs or weapons, however. They brought food and medical supplies to the Bajoran resistance. At least, that was the story that Gose Kannurn, his mentor and adopted father, taught him. Kannurn was a doctor in the resistance, and took Daniel in after his parents were killed.
Daniel grew up a Bajoran in every way but biology, fighting in the resistance and learning medicine from his new father, but also learning about the Prophets, becoming a believer. Of course, his human origins added confusion growing up, a confusion he still deals with. As much as he considers himself a Bajoran, he worries that the Prophets won't see him that way. More, he wants to know more about his human origins.
It was only after the occupation ended and he was able to leave that he began to investigate his origins. This led to him, not long after, joining Starfleet Academy. By the time he graduated, the war was underway and he was once again fighting Cardassians. His first assignment, the USS Ingenuity, was destroyed at the second Battle of Chin'toka, and he was one of the survivors that the USS Bastion ferried to Hephaestus station right before the discovery of the Zachra and the chaos surrounding that.
After everything was settled, he was reassigned to be their new chief medical officer.
