The Washington Post reports:

A much-debated theory holds that 4 billion years ago, give or take, long before the appearance of dinosaurs or even bacteria, the primordial soup contained only the possibility of life. Then a molecule called RNA took a dramatic step into the future: It made a copy of itself.

Then the copy made a copy, and over the course of many millions of years, RNA begot DNA and proteins, all of which came together to form a cell, the smallest unit of life able to survive on its own.

Now, in an important advance supporting this RNA World theory, scientists at the Salk Institute for Biological Studies in La Jolla, Calif., have carried out a small but essential part of the story. In test tubes, they developed an RNA molecule that was able to make accurate copies of a different type of RNA.

The work, published in the journal Proceedings of the National Academy of Sciences, gets them closer to the grand goal of growing an RNA molecule that makes accurate copies of itself.

“Then it would be alive,” said Gerald Joyce, president of Salk and one of the authors of the new paper. “So, this is the road to how life can arise in a laboratory or, in principle, anywhere in the universe.” [Continue reading…]