The graph shown above is from one of the most well-known and on-going ecological studies ever performed. Isle Royal National Park, an island on Lake Superior, keeps data of populations of wolves and moose living there. The moose are a major food source for the wolves. Based on the graph, how does the moose population affect the population of wolves? A) As moose populations increase, wolf populations immediately increase. B) As wolf population falls, moose populations fall with a delayed effect. C) Moose populations don't really show any relationship to wolf carrying capacity. D) The wolf carrying-capacity rises as moose populations increase, but with a delayed effect.
