Practice problem
Why would it be difficult to study evolutionary changes in ancient jellyfish?
Jellyfish do not contain any carbon or potassium isotopes
Jellyfish fossilize too frequently and in too many areas to accurately determine their age
Jellyfish are not as likely to fossilize as other organisms
The ocean washes away any evidence that can be used for relative dating
Type a concept, like “slope” or “photosynthesis”.