Which of the following statements about beta diversity is TRUE?
a. Beta diversity is the number of species found in one location at one time.
b. All else being equal, specialists are likely to be more common where beta diversity is low.
c. Relatively flat, homogeneous habitats tend to have higher beta diversity.
d. Beta diversity may change if you measure it at a different scale.

Three of the statements below are reasons Paul Ehrlich and E.O. Wilson offer for protecting biodiversity. Which is not one of these reasons?
a. Earth cannot "survive" another mass extinction event.
b. People have an aesthetic and moral obligation to protect Earth's species.
c. Earth's biodiversity may provide us with important new resources in the future.
d. Loss of biodiversity may reduce ecosystem services that would be difficult to replace.