I'm very familiar with the Ancients, but I can't remember if they came from planet Earth, originally. I remember an episode about an ancient device that may have been used to create life on Earth when the now human civilization grew and that they are based off of the Ancients. The one Ba'al tried to use to "recreate" the life in the galaxy.
Does that mean that the Ancients didn't come from Earth originally, or am I misreading something somewhere, and they really did come from Earth, traveled to Atlantis, then traveled back to Earth and ascended?
I'm referring to SG1, primarily.