Do organisms in the tropics have lower extinction rates than organisms living elsewhere on Earth? In other words, do the tropics have lower “species and genera death rates” than other regions do? To figure this out, scientists need to collect data about where on Earth different ancient organisms lived (in the tropics, in a non-tropical region, or in both tropical and non-tropical regions) and then find out how many of these organisms went extinct. This is a lot of work, and we could use more evidence. Let’s take a look at the evidence we do have …

This graph is pretty complicated. Click through and answer the following questions to make sure you understand it.

• What does the red line represent?
• Which part of the graph represents our most recent history (e.g., the past 1 million years)?
• When do foraminiferan extinction rates seem to peak?
• Does the graph support the hypothesis that the tropics are a museum?