From The Stargate Omnipedia

An Athosian man, father to Teyla Emmagan. Tagan was taken by the Wraith, and is almost certainly dead.

Tagan also had the name "Torren," perhaps as a middle name. Teyla honored her father (and her friend John Sheppard when she named her child "Torren John Emmagan."


Rising, Part 1 - Greeting the humans of Earth for the first time, Teyla introduces herself as a daughter of Tagan.
The Gift - Teyla learns the secret of her genetic inheritance, which her father wished her never to know -- that he passed on Wraith DNA to her.
Search and Rescue - Teyla announces that she is naming her child "Torren John," after her father and Colonel Sheppard.