Unravel the mystery of the first form of evolution on Earth

Scientists have worked “for generations” to solve the mysteries of how life began on Earth, and one fringe theory has previously become the subject of interesting debate.

The “RNA World” theory says that the so-called “primordial soup of the early Earth” was teeming with DNA’s single-stranded sister RNA, which carries the instructions needed to sustain life.

Now, a team at the US Salk Institute has unraveled and built an important piece of this puzzle in the laboratory: a mysterious but essential class of molecules called RNA polymerase ribozymes.

Scientists believe that RNA polymerase ribozymes contributed to the replication and evolution of RNA in the jelly and clay of the early planet.

Their experiments showed that RNA polymerase ribozymes could not only transcribe RNA, but could make copies of themselves capable of transcribing RNA as well.

They can improve and develop the process of RNA transcription, the same type of evolution described by Charles Darwin: the more malleable an organism is, the more likely it is to reproduce and pass on its genetic material. He knew nothing about DNA, but DNA is the way genes are transmitted.

The new experiment indicated that some kind of evolution may have been occurring in the “RNA world” scenario. As some RNA polymerase ribozymes become better at transcribing RNA, they are more likely to survive and continue to do their job.

“We are chasing the dawn of evolution,” said Gerald Joyce, senior author of the study and head of Salk. “By uncovering these new capabilities of RNA, we are revealing the potential origins of life itself, and how simple molecules could pave the way for the complexity and diversity of life we ​​see today.” ".

Eventually, RNA contributed to the familiar double-stranded structure of DNA, giving rise to single-celled organisms and then more complex life forms.

These are all just theories, because we can never go back to the beginning of the planet and confirm how it all began. But building RNA polymerase ribozymes in the lab and watching them help RNA evolve adds weight to the RNA World theory because it shows that this was theoretically possible.

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