Describe what is happening to:
the extinction rate over time.
human population growth over time.

The two curves have been graphed together. What is the implication of presenting these data in this manner?

The y axis is labeled “Extinction numbers.” What taxonomic units are being measured? What if the taxonomic unit being evaluated here had been genus or family? Would you be more concerned about the trend of extinctions or less? Explain.

What type of relationship is suggested by the figure (correlational or causal)? What additional data would you like to see to support the graph’s main point?