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Read this passage about two inherited traits in threespine sticklebacks. Threespine sticklebacks are small fish found in oceans or lakes. They may have sharp spikes called pelvic spines on their bellies. Same sticklebacks have long spines that stick out from their bodies. Others have short spines that are hardly visible. Long spines can protect sticklebacks from larger fish. pelvic spines Larger fish cannot swallow sticklebacks with long spines as easily as they can swallow sticklebacks with a threespine stickleback with long pelvic short spines. However, some insects catch ape Ree sticklebacks by grabbing their spines. These insects can catch sticklebacks with long spines more easily than they can catch sticklebacks with short spines. The threespine sticklebacks' environment changed to have significantly fewer large fish. After this change, aver a time period long enough for natural selection to occur, the percentage of the threespine stickleback population with long pelvic spines decreased. Use the theory of natural selection to construct a possible explanation for how the threespine stickleback population adapted to its changed environment. Having short pelvic spines was * advantageous than having long spines after the environment changed. So the alleles for long spines were passed on with frequency than the alleles for short spines. As a result, the proportion of the population with short spines * . Over time, the population adapted such that the percentage of sticklebacks that were protected from large fish but more easily caught by Insects 7