For this science journal, your task is to construct claim, evidence, and reason statements about how the population of wolf and elk changed over time in Yellowstone National Park
NPS Graph 2011.PNG
The above graph shows how the population of wolf and elk changed over time in Yellowstone National Park. Review the graph and answer the questions below:
Claim: Looking at the graph, have the population of elk increased or decreased over the years?
Evidence: What do you observe in the graph that supports your statement?
Reason: Why do you think the population of elk increased or decreased? Consider what their relationship is to the wolf and how the wolf data changed over time.
Claim: The population of elk in Yellowstone National Park has decreased over the years.
Evidence: The graph shows a sharp decrease in the population of elk from around 1997 to 2006.
Reason: The population of elk decreased over time likely due to the reintroduction of wolves into Yellowstone National Park in 1995. As the wolf population increased, they began preying on elk, leading to a decline in the elk population. This predator-prey relationship resulted in a decrease in the elk population over the years.