Question

select all the correct answers.
a population of mussels was observed in a particular ecosystem. crabs have recently been observed occupying this ecosystem, which is a novel environment for this crab species. it was found that crabs preferred these mussels as their favorite food. a few of these mussels developed a thicker shell to protect themselves from crabs found in the region. which three statements does this adaptation suggest?
a change in the environment led to a new distribution of traits in a population.
the trait of shell thickening underwent natural selection.
the trait for shell thickening will not be selected by future mussel generations.
half of the mussel population developed the trait while the other half did not.
mussels with the shell thickening trait had a greater chance of survival.

Explanation:

1. For "A change in the environment led to a new distribution of traits in a population": The new predator (crabs) is an environmental change, so trait distribution (thicker shells) changes. Correct.
2. For "The trait of shell thickening underwent natural selection": Since thicker - shelled mussels survive better (as crabs can't eat them easily), this trait is selected. Correct.
3. For "Mussels with the shell thickening trait had a greater chance of survival": Thicker shells protect from crabs, so they survive more. Correct.
4. For "Half of the mussel population developed the trait while the other half did not": Traits are not developed in half - half randomly; it's about natural selection and genetic variation, not a 50 - 50 split. Incorrect.
5. For "The trait for shell thickening will not be selected by future mussel generations": If the environment (crabs) remains, the trait will be selected as it aids survival. Incorrect.

Answer:

• A change in the environment led to a new distribution of traits in a population.
• The trait of shell thickening underwent natural selection.
• Mussels with the shell thickening trait had a greater chance of survival.