Who is Luke Morrison from Crow Lake and what is their importance?

Luke Morrison is the eldest of the Morrison children. The day before his parents are killed in a car accident, Luke learns that he has been accepted into teacher's college. This acceptance makes Luke the first of the Morrison family to ever go to college. However, Luke has never been a good student and he seems only lukewarm about the idea of attending. In the end, Luke gives up teacher's college so that he can take custody of his siblings and allow Matt to go to university instead.