This is how the ingredients of life were ‘cooked’ on the early Earth

2024-04-03 15:00:10

However, from our own experience we know that it is not easy for these basic biological ‘bricks’ to transform into authentic living beings. At least not everywhere.

Now, thanks to the experiments of a team of researchers at the University of Munich, we know that heat flowing through cracks in rocks, such as those found in volcanoes or geothermal systems, is capable of filtering and purify molecules important for the chemical origins of life. The study, which is published in ‘Nature’, finally offers an explanation of how those first basic components could be formed from the original complex chemical mixtures.

Filtering what is important

The formation of biopolymers and their components marked a milestone in the history of the origins of life on the early Earth. However, the mechanisms that made this possible have proven impossible to replicate in the laboratory. Often, in fact, the large amount of byproducts and waste that are formed from these complex reactions makes the small number of truly useful building blocks irrelevant. Furthermore, none of these overly specific experiments were able to isolate a wide range of molecules at once. In other words, until now no one had managed to devise a truly effective purification method capable of explaining how the biochemical bases of life arose.

Something that Christof Mast and his colleagues have just achieved by using a series of small volcano-shaped chambers, with tiny cracks (just 170 nanometers) to separate more than 50 molecules relevant to prebiotic life from complex mixtures of amino acids, nucleobases, nucleotides and other compounds. Similar vast networks of cracks can be found in the Earth’s crust, and are thought to have also been abundant on Earth before life existed. According to the study, this is how the newly formed ‘soup’ of chemical components of the Earth was filtered and purified thanks to the heat of these cracks, which allowed the isolation and enrichment of the specific molecules necessary to ‘start’ the mechanism. of the life.

The results of these experiments show that even a moderate temperature difference would have been sufficient to separate and purify several types of prebiotic molecules, including 2-aminozoles and amino acids, increasing their concentrations by a factor of ten and three orders of magnitude, respectively.

The researchers found that these concentration ratios could be further improved by increasing the size of the crack network, and proved successful when applying a wide range of temperatures, solvents and different pH values. Mast and his team, in addition, also managed to demonstrate that the conditions applied in their experiments facilitate the coupling of two glycine molecules, a starting point in the synthesis of peptides, with the help of the formation of concentrations five times higher than the mixture. initial.

The success of the applied method therefore leaves little doubt, and suggests that natural geothermal heat flows could have driven this molecular separation on the early Earth. From now on, scientists finally have an efficient method to produce and study in much more detail the compounds necessary for the origin of life.