Where Life Arose
Life could not have come into being on Earth until after about 4 billion years ago,when bombardment by asteroids had subsided substantially.Even after Earth’s surface had stabilized,certain conditions were required for the origin of life.Some researchers have concluded that precursor compounds,and ultimately life itself,arose in small bodies of water that were struck by lightning and turned into what is sometimes referred to as the “primordial soup”of organic compounds.The problem with that idea is that it would have required an atmosphere lacking oxygen,because even a small amount of oxygen would have oxidized,and thereby destroyed,chemical raw materials necessary for the production of essential organic compounds.
完整版题目和答案请付费后查阅
