The Foundation for Applied Molecular Evolution today announced that RNA (ribonucleic acid), which is an analog to DNA, spontaneously forms in the basalt variant of lava glass. This glass was found on Earth around 4,350 million years ago. Similar basalts from this antiquity are still found on Mars today.
Communities studying the origins of life have deviated over the past years, commented Steven Benner. He has co-authored an online study in the journal called Astrobiology.
Benner explained that one community visits again the classic questions which have complexity in their chemical schemes, that require skilled chemists to perform difficult chemistry. Their beautiful work appears in prestigious journals like Nature or Science. It cannot, however, account for the origin of life on Earth because of its complexity in chemistry.
The Foundation study, however, takes a more straightforward approach. The Foundation study, led by Biondi (Elisa Biondi), shows that RNA molecules with long (containing around 100 to 200 nucleotides) form as Nucleoside Triphosphates only perform percolation through basaltic glasses.
Stephen Mojzsis (a geologist who partaken in the study) said that basaltic glass was present everywhere on Earth at that time. “Molten basaltic volcanic lava was formed by frequent impacts and abundant volcanism over several hundred million years after the Moon’s formation. Aquifers were also created by impacts that evaporated water, allowing for the formation of RNA. These same implications also produced nickel, which was also shown by the team to give nucleoside triphosphates derived from nucleosides. The formation of these triphosphates is controlled by borate (as found in borax), also from basalt.
Transiently, the same impactors who formed glass also reduced the atmosphere with their iron-nickel cores. These atmospheres are where RNA bases, which store genetic data, can be formed. Previous research by the team showed that nucleosides can be formed simply by reacting ribose phosphate with RNA bases.
Jan Spacek, a high school chemistry teacher who developed an instrument that detects genetic proteins of aliens on Mars, said that it can be tested by students in high school. He wasn’t a part of the study. Mix the ingredients and wait for the RNA to form. This is a non-complex model and its beauty lies in simplicity.
These same rocks can resolve other paradoxes when making RNA. They move all the way from simple organic molecules to the first RNA. Benner explained that borate is responsible for the formation of ribose (the ‘R’ in RNA). This path begins with simple carbohydrates, which could not have been formed in the atmosphere above primitive Earth. They were then stabilized with volcanic sulfur dioxide and rained to the surface in order to form reservoirs of organic mineral minerals.
This work concludes a pathway that creates DNA from small organic molecules, which were almost certain to have been present in the early Earth. One geological model uses one to two carbon molecules to create RNA molecules that are long enough for Darwinian evolution.
“Important questions remain,” cautions Benner. “We don’t know the exact mechanism by which all RNA building blocks have the same shape. This relationship is known as homochirality.” The linkages between nucleotides in basaltic glass can also be variable.
Mars is relevant because of the same minerals, impacts, and glasses that were present on Mars in antiquity. But, Mars has not experienced continental drift or plate tectonics which buried most of the Earth’s older rocks. Therefore, Mars still has rocks from the relevant period. All of the required rocks have been found on Mars by recent missions, including borate.
Benner stated, “If life emerges on Earth by this simple route, then it will most likely also emerge on Mars.” This makes it more crucial to find life on Mars as soon and as possible.
