Scientists Reconstruct Earth's Ancient Ocean to Find Origins of Life

Our ancient Earth played home to oceans that were far different than the ones of today. Now, scientists have taken a closer look at these waters and have found details about how the first organisms on our planet could have become metabolically active.

Almost 4 billion years ago, life on Earth began in the iron-rich oceans that dominated the surface of our planet. Yet scientists have long wondered when and how cellular metabolism, the network of chemical reactions needed to produce the building blocks of life, appeared.

In order to learn more about the early history of Earth, the researchers decided to reconstruct our planet's earliest ocean. They based their reconstruction on the composition of various early sediments described in scientific literature.

They found that there was a spontaneous occurrence of the chemical reactions used by modern cells to synthesize many of the crucial organic molecules of metabolism. Previously, scientists assumed that these reactions were carried out in modern cells by metabolic enzymes, highly complex molecular machines.

"Our results demonstrate that the conditions and molecules found in the Earth's ancient oceans assisted and acceleration the interconversion of metabolites that in modern organisms make up glycolysis and the pentose-phosphate pathways, two of the essentially and most centrally placed reaction cascades of metabolism," said Markus Ralser, one of the researchers, in a news release. "In our reconstructed version of the ancient Archean ocean, these metabolic reactions were particularly sensitive to the presence of ferrous iron that helped catalyze many of the chemical reactions that we observed."

The findings reveal a little bit more about how life might have started in our ancient seas. This could also be applicable for discovering life on other planets.

The findings were published in the journal Molecular Systems Biology.