- It turns out that increased oxygen levels didn’t trigger the arrival of more complex marine life.
- This has been determined by analyzing thallium isotopes found in sedimentary rocks from the Omani mountains.
- Instead, the researchers found that the lack of oxygen may have led to the development of multicellular organisms.
Most organisms on the planet need oxygen to survive.
This colorless, odorless, and tasteless gas is the most abundant element by mass in the Earth’s crust. The third is the most common One in the universe.
But while it currently makes up about 21 percent of Earth’s atmosphere, oxygen was largely absent during Earth’s first billion years or so. A step 2016 MIT study, which began to form during the Great Oxidation Event about 2.33 billion years ago. Cyanobacteria living in the oceans began to produce oxygen through photosynthesis.
A little later, the Precambrian „Avalon Explosion” (about 575 million years ago) marked the appearance of widespread multicellular organisms in Earth’s oceans. Before this, marine life was dominated by single-celled organisms such as amoeba, algae and bacteria.