This week on Points North we'll talk with Knute Naddelhoffer. As the director of the University of Michigan Biological Station near Pellston, Knute has a front row seat to view the changes to northern Michigan's ecology caused by the gradual warming of the earth. These and other changes to the natural world "up north" are the subject of a new book. Its chapters are written by scientists who have taught at the field station on the shores of Douglas Lake. Knute is the editor and he joins us this Friday at 9 a.m.