"the Big Bang Theory" Pilot(2007) Access

: The original female lead was Katie (Amanda Walsh), a cynical, "street-hardened" character who was often mean to Leonard and Sheldon. Audience feedback led to her being replaced by Penny (Kaley Cuoco), who was written to be more endearing.

The series originally shot a pilot in 2006 that was significantly different from the version that premiered on September 24, 2007. "The Big Bang Theory" Pilot(2007)

: The unaired pilot featured a female scientist named Gilda (Iris Bahr) instead of Howard and Raj. Creators Chuck Lorre and Bill Prady added Howard Wolowitz and Raj Koothrappali for the aired version to balance the group dynamic. : The original female lead was Katie (Amanda