An international team of scientists from Australia and the USA has discovered microfossils that show the development of more complex life forms approximately 2.4 billion years ago. This trend coincided with the increasing concentration of oxygen in our planet’s atmosphere. The study was published in the scientific journal magazine geobiology
The oxygenation of Earth’s environment, also known as the Great Oxidation Event, is believed to have led to the mass extinction of organisms on ancient Earth. Now archaeologists have found evidence of an evolutionary leap linked to increasing oxygen levels.
By analyzing the chemical composition and carbon isotopic composition of the microfossils, the researchers determined that the carbon was created by living organisms, confirming that the structures were indeed biological fossils. They also revealed information about the habitat, reproduction and metabolism of microorganisms.
Compared to modern organisms, microfossils have clear similarities to algal colonies, including the shape, size, and distribution of both the colony and individual cells, and the membranes around the cell and colony.
Scientists say the findings hold clues about both how long it took for complex life to form on early Earth (the oldest, most convincing evidence of life is 3.5 billion years old) and what the search for life elsewhere might reveal: the solar system.
Previous researchers in the name Another reason why dinosaurs went extinct.