Ancestral memory, also known as race memory, was a memory of racial history present at birth in an individual. This resulted from an event repeated enough times that it was incorporated into a species' genome. The Tractators once invaded Trion, causing future Trions to be terrified of them. Turlough went into shock after seeing Tractators as they awakened the ancestral memory within him. This allowed him to remember how the Trions had previously defeated the Tractators by separating them from the Gravis. (TV: Frontios)