There Are Currently Two, Large, Permanent Bridges That Span the Panama

question 61

Multiple Choice

There are currently two, large, permanent bridges that span the Panama Canal. The bridges are about 8 miles apart. If snapping shrimp avoid swimming at night and avoid swimming under shadows, then what do these bridges represent for the snapping shrimp?

• A) sources of refuge
• B) geographic barriers
• C) sources of a hybrid zone between the two bridges
• D) sources for increased gene flow