unnecessary traits might not always lead to extra cost, and even then, the extra cost might not always lead to extinction.
the extinction usually happens when a trait that represents a disadvantage in a sufficiently heavy competition for survival. If the competition is low enough, the trait may survive.
unnecessary traits might not always lead to extra cost, and even then, the extra cost might not always lead to extinction.
the extinction usually happens when a trait that represents a disadvantage in a sufficiently heavy competition for survival. If the competition is low enough, the trait may survive.