What is the overall objective of Experiment 1 in the stickleback study?

• A. To map the entire genome of stickleback
• B. To measure dorsal spine length only
• C. To analyze the pelvic structures of stickleback fish collected from two lakes near Cook Inlet, Alaska, and infer environmental factors that influence pelvic morphology
• D. To compare feeding habits across lakes

Answer: (C)

The main idea here is how the environment shapes physical traits by comparing populations. In this experiment, researchers collect stickleback from two lakes near Cook Inlet, Alaska, and analyze their pelvic structures. This setup lets them see whether pelvic morphology differs between populations living in different lake environments and to infer which environmental factors—such as predator presence, habitat structure, or other ecological conditions—are associated with those differences. Focusing on the pelvis shows they’re testing how ecological context can drive adaptive changes in a specific trait. The other options don’t fit because this study isn’t about mapping the genome, or measuring only dorsal spine length, or examining feeding behavior across lakes.