Life on Earth could have a different origin than previously thought

by Julio Garcia G. / science journalist

There is still extensive debate about whether RNA (RNA), which is found in some viruses such as SARS-CoV-2 and many others, before Nuclear deoxyribonucleic acid (DNA), of which all living organisms, including the simplest, consist.

RNA, unlike DNA, It is made up of one string. While the latter is formed Two chains in the form of stairs.

The basic units of these series are nucleotidestheir chemicals Transfer of genetic information into cells. Hence its importance in the life processes of both DNA and RNA molecules.

In this sense, for MD, Maria Capa, a researcher in the department of biology at the University of Les Iles Palares in Spain, and author of an article recently published in the paper CountryAnd the “It is possible that the first organisms had some molecules that facilitated the association of nucleotides and the replication of DNA or RNA.”

As it mentions “The solution to the question of the appearance of DNA or RNA for the first time has been of scientific interest since the discovery of these molecules”

RNA structure. Photo: shutterstock

To settle this debate about which came first, DNA or RNA, a research paper was recently published in the journal astrobiologyindicates that RNA spontaneously forms in Basalt lava glass. This means that – based on this new model – RNA came before DNA.

Basalt lava glass was abundant on Earth about 4.3 billion years ago Volcanic activity on our planet was more intense which is happening today. Besides, and this is the strangest thing ever, This type of lava glass is still alive on Mars. So the RNA can be present not only on Earth, but also on other planets.

The new work was led by Dr. Elisa Biondi of Foundation for Applied Molecular Evolution from the United States, who, with his team, showed that long RNA molecules – about 100 to 200 nucleotides – are formed when nucleoside triphosphate filter through Basalt glass.

The nucleoside triphosphate They are the precursors of both DNA and RNA and serve as An important source of energy Because many cellular interactions occur.

DNA structure. Photo: shutterstock.

In this sense, according to the statements made to the Internet portal Phys.OrgStephen Mogesses, an Earth scientist who was also involved in this important work, noted, “For several hundreds of millions of years after the formation of the Moon, both are recurring influences.” [de meteoritos] Such as abundant volcanoes What was on that young land, Basalt lava formed spitWhich is the source of basalt glass. The effects also evaporated water to form dry land, providing aquifers where RNA can form.

The basalt it’s a Igneous rock typeperhaps the most common, that originates When the magma produced by volcanoes cools and becomes solid. In fact, basalt is not only found on the surface and bottom of the Earth’s oceans, But it is also found on Mars and the Moon.

Research by Elisa Biondi and colleagues can also test the hypothesis that RNA is created from small organic molecules It was very likely that they were present on that primal land.

Regarding what happened on Mars when it was formed, it turns out that the world next door to us is made up of both With the same minerals as the same basalt crystals existing on the ground. The difference is that On Mars, there is no movement of the continents (Continental Drift) No Tectonic plates that characterize our planet.

These tectonic movements and this continental drift produced that Most of the rocks on Earth that existed over 4 billion years ago are buried. on Mars, These rocks are still present on its surface. sOr what our neighboring planet would be the perfect place to do Deeper about the search for RNA molecules.

The surface of Mars. Photo: NASA.

By the way, I’m sure she will be very satisfied with the study that Elisa Biondi and her team is the Mexican scientist Rafael Navarro Gonzalezwho passed away in January 2021.

Navarro Gonzalez, who opened the field of astrobiology in Mexico, decided to devote a large part of his work Life to study the planets and their relationship to the presence of living organisms on them. Throughout his career, Navarro made several trips to Antarctica, where he found organic matter and microbes, which led to the conclusion that the existence of life can be found Even in remote and inhospitable places.

As for what the new Bundy investigation holds for the future, there are still many questions that need to be answered. for example, It is still unknown how all the building blocks of RNA came to have the same shape. When all components have the same structure it is known as homosexuality.

The homosexuality is property of Amino acids. The latter are molecules that combine to form proteins. Proteins, in turn, regulate most functions in all living things.

Dr.. Rafael Navarro Gonzalez. Photo: Cuartoscuro/NASA. Treatment: not available

It turns out that many amino acids produce chiral proteinswhich has been translated by The ribosome. The latter is a structure inside the cell that consists, precisely, of RNA and other proteins. And thanks to these ribosomes (there are many in cells), RNA can give instructions to proteins About the functions they have to perform in the body.

The other fundamental question that the Bondi study failed to answer has to do with the fact that How simple life can become so complex as we know it today.

It is clear that evolution has played a fundamental role in the complexity of the evolution of living organisms. But how were these step-by-step processes produced? Will there be a way to discover and reconstruct the history of life on our planet and, if it exists, in other parts of the universe? remains to be seen.

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