Eider ducks live in the ocean and have a layer of warm feathers underneath their regular feathers. They can have thin feathers, medium feathers, or thick feathers.

Question

These feathers help the ducks stay warm in cold water. Ducks with thicker feathers are more likely to stay warm and survive in cold water. But, in warm water, thicker feathers can make the ducks overheat and die.

Diagram titled Population containing 2 rows of duck icons. The first row is labeled Medium and contains 2 bird icons. The second row is labeled Thick and contains 6 bird icons.
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16. The population of ducks shown above lives in an environment that has always had very cold water. Could there ever have been ducks with thin feathers in this population?

Responses

a
No ducks could have been born with the thin-feather trait because none of the adult ducks had that trait to pass down.
No ducks could have been born with the thin-feather trait because none of the adult ducks had that trait to pass down.

b
No ducks could have been born with the thin-feather trait in the past, but some with that trait could be born in the future if the environment changes to be warmer.
No ducks could have been born with the thin-feather trait in the past, but some with that trait could be born in the future if the environment changes to be warmer.

c
A duck could have been born with a mutation in its genes for the thin-feather trait and lived for a little while, but it would have been more likely to die before it had offspring.
A duck could have been born with a mutation in its genes for the thin-feather trait and lived for a little while, but it would have been more likely to die before it had offspring.

d
A duck could have been born with a mutation in its genes for the thin-feather trait, but having a mutation in its genes would have caused it to die when it was born.

Answer 1

The best response to the question of whether there could ever have been ducks with thin feathers in a population living in an environment with consistently cold water is:

b. No ducks could have been born with the thin-feather trait in the past, but some with that trait could be born in the future if the environment changes to be warmer.

This response acknowledges that while thin-feathered ducks might not be viable in a consistently cold environment (as they would struggle to survive and reproduce), they could have been born in the past if the environmental conditions shifted. Additionally, it reflects the principle that traits can arise but may not persist in a population if they are disadvantageous in the given environmental context.