If flight is such an advantage,how do we account for the evolution of flightless birds?
A)They were primitive ancestors of the winged birds
B)Flight is costly in terms of energy so birds abandon flight if they live in areas with food and without substantial predators,such as islands
C)This is always an inferior situation if they can't fly,so wingless birds occur only where winged birds are missing
D)Birds give up flight if they can avoid having to lay eggs
E)None of the choices is correct

Question

Quizplus · Accepted Answer

Flight is indeed costly in terms of energy, which means that in areas where there is enough food and few predators, flight may not be necessary for survival. This is why flightless birds, such as ostriches, emus, and kiwis, have evolved in some environments. However, this does not mean that flight is always an inferior situation, as many birds rely on flight for migration, hunting, and escaping from predators.

If Flight Is Such an Advantage,how Do We Account for the Evolution