Commander Sela is a fictional character on Star Trek: The Next Generation, the daughter of an alternate timeline version of Tasha Yar and a Romulan official. She was played by Denise Crosby, who also played Tasha Yar.Sela's mother, Tasha Yar, was born in 2337 on Turkana IV and in the "normal" timeline died in 2364, killed by Armus on Vagra II. But in an alternate timeline, seen in the episode "Yesterday's Enterprise", Yar either survived or avoided the confrontation with Armus and continued to serve on the Enterprise-D until 2366, when the Enterprise-C came through a spacetime anomaly. It was determined that the accidental time travel of the Enterprise-C drastically altered the timeline after its disappearance from the past, and that the original timeline should be restored by sending the ship back.