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  • Category: Culture

560-520 million years ago, various animal phyla appeared and expanded rapidly in a relatively short period of time, forming an animal-dominated marine ecosystem. This major event in the history of life evolution is called the Cambrian Explosion. For some time, its cause has been a hot topic of concern in academia. The traditional view is that it may be related to the oxidation of the ocean. The increase in the oxygen content of seawater has brought about the "explosive" appearance of early animals. However, relevant studies have shown that early animals did not have a high demand for oxygen. There is also a view that ocean oxidation is the result of the Cambrian Explosion, not the cause. It can be seen that the feedback mechanism between the early Cambrian ocean oxidation and the "explosion of life" is still unclear and needs further exploration.

The reporter learned from the University of Science and Technology of China that recently, Wei Wei, an associate researcher, Dong Linhui, a doctoral student, Huang Fang and others published their research results in the National Science Review (NSR), proposing that seawater oxidation played the role of a water purifier, removing sulfides and barium ions that were toxic to early animals, thereby promoting the Cambrian Explosion of Life.

Wei Wei and others analyzed sedimentary rocks deposited in Hunan and Guizhou during the heyday of the Cambrian Explosion of Life and found that the gradual oxidation of the ocean 560-520 million years ago increased the concentration of sulfate ions, causing the previously accumulated dissolved barium ions to be removed in large quantities in the form of barite. High concentrations of barium in water bodies inhibit the survival rate of aquatic animals. Therefore, the removal of sulfides and barium ions that are toxic to animals improved the habitability of the ocean, thereby promoting the Cambrian Explosion of Life. This discovery provides new insights into the feedback mechanism between the oxidation of the ocean in the early Cambrian and the "explosion of life."