Dr. Kari Tolppanen argues that the author of the Gospel of Luke did not derive his common material with the Gospel of Mark from canonical Mark. He bases his thesis on three major observations: First, Luke clearly emphasizes certain theological themes in Luke-Acts, but interestingly, these themes are sometimes missing in Luke's passages while present in Mark's parallel passages. Second, there are significant differences at both macro and micro levels between the Lukan and Markan Passion-Resurrection sections and their non-Passion-Resurrection sections, suggesting that Luke did not derive these two blocks of text from the same source. Third, great variation in verbatim agreement levels between Luke and Mark's parallel passages runs against known ancient editorial practices and the human tendency towards consistency in editing. In his conclusion, the author suggests that Luke did not derive his common material with Mark from canonical Mark but from a parallel source. This parallel source and canonical Mark had the same origin but different development histories probably due to the interaction of orality and literacy. This explains the inconsistencies between Luke and Mark.