Answer
Earth's atmospheric oxygen level is closely linked to the evolution of life. In the late Paleozoic era, around 300 million years ago the level of atmospheric oxygen was much high than that of today. Due to this reason, many animal groups showed an increase in size, in some insects, and the wingspan enlarged to two feet.
Oxygen is involved in aerobic metabolism, which is a biochemical process that uses oxygen for the generation of energy from nutrient molecules. It is a far more effective process than anaerobic metabolism that does not use oxygen for energy generation.
The primitive atmosphere of Earth was reducing (oxygen deficient). UV(ultraviolet) radiations striking the surface of the Earth were so intense that it destroyed many organisms. The accumulation of atmospheric oxygen and photosynthetically generated oxygen more than 2 billion years ago gradually produced a thick and uniform ozone layer in the stratosphere. This ozone layer was sufficiently dense and absorbed the maximum amount of the UV radiation, which made the organism to leave and come out of the water to invade the land.
Therefore it can be concluded that the increase in atmospheric oxygen level has led to the invasion of various life forms on the land
Work Step by Step
Earth's atmospheric oxygen level is closely linked to the evolution of life. In the late Paleozoic era, around 300 million years ago the level of atmospheric oxygen was much high than that of today. Due to this reason, many animal groups showed an increase in size, in some insects, and the wingspan enlarged to two feet.
Oxygen is involved in aerobic metabolism, which is a biochemical process that uses oxygen for the generation of energy from nutrient molecules. It is a far more effective process than anaerobic metabolism that does not use oxygen for energy generation.
The primitive atmosphere of Earth was reducing (oxygen deficient). UV(ultraviolet) radiations striking the surface of the Earth were so intense that it destroyed many organisms. The accumulation of atmospheric oxygen and photosynthetically generated oxygen more than 2 billion years ago gradually produced a thick and uniform ozone layer in the stratosphere. This ozone layer was sufficiently dense and absorbed the maximum amount of the UV radiation, which made the organism to leave and come out of the water to invade the land.
Therefore it can be concluded that the increase in atmospheric oxygen level has led to the invasion of various life forms on the land
