One study says that meteorites and water lagoons were the source of life

Life began on Earth between 4,500 and 3,700 million years ago thanks to the impact of meteorites on small lagoons on the Earth’s surface, according to a Canadian study just published.

The text explains that meteorites carried essential elements of life, while dry and wet cycles helped to fuse the basic building blocks of molecular structure into RNA (ribonucleic acid) molecules capable of self-replication. These RNA molecules were the first genetic code of life on Earth.

The study, published in the scientific journal Proceedings of the National Academy of Science, was conducted by researchers at McMaster University in Canada and the Max Planck Institute in Germany. Its main authors, Ben K.D. Pearce and Ralph Pudritz of the Origins Institute at McMaster University, pointed out that life began while the Earth was still forming, with continents emerging from the oceans and meteorites impacting the surface. To reach these conclusions, the researchers performed a series of calculations of astrophysics, geology, chemistry and biology, among other disciplines.

The authors indicated that the creation of RNA polymers, the essential component of organic molecules known as nucleotides, transported by meteorites, reached a critical concentration in water lagoons. Polymers were imperfect “capable of improving thanks to Darwinian evolution,” the researchers said in a statement. Pearce stated that “that is the Holy Grail of the origins of experimental chemical life.”

The creation of RNA eventually led to the development of DNA (deoxyribonucleic acid). Pudritz stated that “DNA is too complex to have been the first aspect of life that appeared. It had to start with something else, which was RNA.” His calculations indicate that the warm water lagoons that existed on Earth, and not hydrothermal chimneys at the bottom of the oceans that advocates another theory about the origin of life, are the most likely place where the initial RNA developed.

In addition, space dust would not be the source of nucleotides, the bricks of genetic material. Although it contained the necessary materials, it could not reach the Earth with sufficient speed. For the authors it is more probable that the meteorites, that were much more common in those stages of the Solar System, were the vehicles more probable for the ingredients of the life.