Among all the basic requirements of survival, oxygen is our major priority. While oceans are running out of oxygen and becoming a death pit for underwater animals, they are slowly modifying themselves to exist without oxygen.
According to a new research by the University of California, Berkeley has claimed that the amount of oxygen that we can found now these days in the earth's ocean, was not available when the first animal appeared in this green planet, approximately 800 million years ago.
The research, which was published in the journal Nature, said that scientists used chemicals, found in ancient rock to know the oxygen level of the surrounding ocean and how chemicals were created. After researching collected data, palaeontologists understood the creation of the chemicals of early earth, including oceans and atmosphere.
After analysing the measurement of oxidation from the extrusive igneous rock basalts, scientists found that before 541 to 420 million years ago, there was no sign of oxygenation in the deep sea. It also indicates that the first animal of this planet was developed when there was hardly any oxygen available.
On the other hand, most scientists believe that around 2.5-2.3 billion years ago, the oxygen level has started to increase but the quantity was extremely low compared to today's atmosphere, including in the deep ocean.
"This is significant because it provides new evidence that the origination of early animals, which required O2 for their metabolisms, may have gone on in a world with an atmosphere that had relatively low oxygen levels compared to today," said Daniel Stopler, a geologist at UC Berkeley.
In terms of the recent scenario, the environment experts are concerned about the 'deoxygenation' of oceans. Even though, millions of years ago animals survived with less quantity of the oxygen, with time they became habituated with the high level of oxygen and the sudden downfall of the quantity is threatening their lives.