red state scientists make advance on understanding how life began

[nsacpi]

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.

https://wapo.st/3TdoJBw

[nsacpi]

****...blue state scientists

[nsacpi]

Directed evolution, sometimes called test tube evolution, is a lab process that allows scientists to mimic evolution by guiding molecules from generation to generation, enabling the molecules to acquire improvements that help them survive.

Although the experiments in the new paper took two years, it has taken Joyce and his colleagues closer to 10 years to set the stage, patiently raising generation upon generation of RNA molecules.

Should the scientists succeed in generating an RNA that can copy itself, evolution could then proceed largely on its own.

“All we would need to do is feed it an ongoing supply of the four building blocks,” said Joyce. RNA, like DNA, is made from four chemical bases, three of which are the same for both: adenine, cytosine and guanine. For its fourth component, RNA has the base uracil, while DNA’s fourth is thymine.

The lab version of evolution would allow RNA molecules to adapt as scientists changed the temperature or environment.