Luke's genealogy of Jesus traces his line all the way back to whom?

Answer: Adam

Luke's genealogy runs backward from Jesus and ends with "the son of Adam, the son of God."

“Jesus Himself was about thirty years old when He began His ministry. He was regarded as the son of Joseph, the son of Heli, the son of Enosh, the son of Seth, the son of Adam, the son of God.”— Luke 3:23, 3:38 (BSB)