And why would natural selection have favored the development of little protowings in a theropod equipped with heavily muscled legs for running across the ground?

• 另一方面，兽足类恐龙双腿强而有力，在地面上奔驰毫不费力，天择怎麽会看上牠们的弱小上肢，将它们改造成原始的翅膀？