A swim bladder is a gas-filled sac that helps fish maintain buoyancy and evolved from the lungs of ancient fish. This evolutionary change is an example of which of the following processes?
A) exaptation
B) changes in Hox gene expression
C) paedomorphosis
D) adaptive radiation

Question

Quizplus · Accepted Answer

Exaptation refers to a trait that has been co-opted for a use other than the one for which natural selection has built it. The swim bladder is an example of exaptation, as it evolved from the lungs of ancient fish to help modern fish maintain buoyancy.

A Swim Bladder Is a Gas-Filled Sac That Helps Fish