Interpreting Data A population of snails has recently become established in a new region. The snails are preyed on by birds that break the snails open on rocks, eat the soft bodies, and leave the shells. The snails occur in both striped and unstriped forms. In one area, researchers counted both live snails and broken shells. Their data are summarized here:
Based on these data, which snail form is subject to more predation by birds? Predict how the frequencies of striped and unstriped individuals might change over time.
Striped Shells | Unstriped Shells | |
Number of live snails | 264 | 296 |
Number of broken snail shells | 486 | 377 |
Total | 750 | 673 |
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