|Out of universe information|
Marine is a Marine who appeared in Duet.
Ronon Dex spars with several Marines in the gym, including this man. Ronon easily beats all of them and this Marine complains about the idea of continuing. Ronon later demonstrates Wraith fighting techniques with the Marine as an example and he practices with his fellow Marines as Ronon talks to Dr. Elizabeth Weir. After finishing the conversation, Ronon returns to training the Marines. (SGA: "Duet")