Self-study
Marine biologists have long thought that Conclusion variation in the shell color of aquatic snails evolved as a protective camouflage against birds and other predators. █████ ██████ ████ ██ ██ ████ ████████ ████ ███ ██████████ ████████ ██ ████████████ ███ █████ ██████ ████ ████████ ████ ███ ██████████ ████████ ██ ██████████████ █ ███ ██████ ███ ████ █████████ ████████ ████ ██████ ████ █████ █████ ██ ███████ ██ █████████████ ██████ ██████████ ████ ████ ███████████ █████████ ██ ████ ███████ █████ ██████ ████ ██ ████ █████████ ██ █████ █████ ███ ████ ██████ ██ ███ ███ ██ █████ ███ ████ ████ ██████████ ████ ███ ███ ██ ██████████ ███████ █████ ██████ ████ ██ ████ ████████ ██ ██████ ██████ █████ ███ ██████ ████ ██████ ████ ████ ████ ███ ███████ █████
Just Jot Down Some Notes
Here’s the stimulus distilled:
Old Theory
dark bottom – dark shells
light bottom – light shellsNew Theory
choppy water – dark shells
calm water – light shells
We’re looking for evidence to support the new theory over the old, so we can anticipate one of the following:
- dark shells – choppy water – light bottom
- light shells – calm water – dark bottom
It takes a lot of mental effort to keep all these moving pieces straight in your mind. If you missed this question, or if it took you a long time, the lesson is to just write a few quick notes. It’s like trying to remember a phone number or something – you can probably manage it if you actively keep repeating it to yourself, or you could just write it on a napkin it takes like 2 seconds.
7.
Evidence that would strongly favor ███ ███ ██████ ████ ███ ███████████ ██████ █████ ██ ███ █████████ ██ █ █████ ████████ ██
a
dark-shelled snails in █ ████ █████ ████ █ █████ █████ ██████ ███ ████ █████████
Dark-shelled snails in calm water cuts against the new theory. Dark bottom supports the old theory.
b
dark-shelled snails in █ ████ █████ ████ █ ██████ █████ ██████
Dark-shelled snails in calm water cuts against the new theory. Light bottom does cut against the old theory, though.
c
light-shelled snails in ██ █████ ████ ████ ████ ██████ ███ █ █████ █████ ██████
Light-shelled snails in choppy water cuts against the new theory. Dark bottom does cut against the old theory, though.
d
light-shelled snails in █ ████ █████ ████ █ █████ █████ ██████ ███ ████ █████████
Light-shelled snails in calm water supports the new theory. Dark bottom cuts against the old theory.
Winner!
e
light-shelled snails in █ ████ █████ ████ █ ██████ █████ ██████ ███ ████ █████████
Light-shelled snails in calm water does support the new theory. But light bottom supports the old theory.