Chemical Component Protection Helped Start Life on Earth

Life first began on Earth billions of years ago. Exactly how it began, though, still remains uncertain. Now, scientists have discovered that the chemical components crucial to the start of life on Earth may have primed and protected each other in never-before-realized ways. The findings could allow researchers to better understand how our planet first began to house organisms.

Researchers have long thought that life began when the right combination of bases and sugars gathered together and produced self-replicating ribonucleic acid, also known as RNA. This RNA was located inside a rudimentary "cell" that was composed of fatty acids. Under the right conditions, these fatty acids naturally form into bag-like structures that are similar to today's cell membranes.

In order to examine the origin of life a bit more in depth, the researchers tested one of the fatty acids, called decanoic acid, representative of those found before life began. They found that the four bases in RNA bound more readily to the decanoic acid than did the other seven bases tested. In fact, by concentrating more of the bases and sugar that are the building blocks of RNA, the system would have been primed for the next steps--reactions that led RNA inside a bag.

Actually driving RNA inside a bag, though, is relatively easy in comparison to creating RNA from scratch. Yet if the parts that come together to create RNA preferentially stick to the surface of bags, everything becomes a bit easier. The researchers also found that the same bases of RNA that preferentially stuck to the fatty acid also protected the bags from the disruptive effects of salty seawater--something that would have been extremely useful on our early Earth.

"Taken together, these findings yield mutually reinforcing mechanisms of adsorption, concentration and stabilization that could have driven the emergence of primitive cells," said Sarah Keller, one of the researchers, in a news release.

The findings reveal a little bit more about how life may have first originated on Earth. In addition, it shows a little bit more about chemicals bind, which could have implications in future research.

The study is published in the journal Proceedings of the National Academy of Sciences.