This is exactly what the young-earth creationist view of adaptation would suggest. The kind of lizard from which Italian wall lizards descended had the genetic instructions for cecal valves. Because Italian wall lizards didn’t need them, however, the genes were not active in that species. They were still there, however. Thus, when the lizards needed to eat more vegetation, the genetic instructions for cecal valves were activated again, allowing rapid adaptation to the new conditions.