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 are correct

Question

Quizplus · Accepted Answer

Flight is indeed costly in terms of energy. Flightless birds can survive on islands without many predators or competition for resources, so they do not need to fly. Additionally, flightless birds may have evolved from their flighted ancestors due to environmental pressures such as the lack of predators or the abundance of resources on islands.

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