Evolution: How life came to Earth

There are many theories about the origin of life, and one particularly widespread assumption is that the first living organisms were in the world Primal soup Which was already full of organic and inorganic molecules billions of years ago.

However, the source of these molecules is more controversial. The astrophysicist says: “There are theories that say that volcanic activity in water led to the formation of these materials, or that it took several dry and wet stages on Earth to form the molecular compounds necessary for life.” Serge Krasnokotsky Gina from Friedrich Schiller University told science.ORF.at.

Cosmic influences

However, in recent years, another theory has become increasingly popular among many researchers: studies have shown that some molecules found in the primordial soup may have had a cosmic origin – e.g. Pettedwhich are a shorter form of proteins or proteins.

These short-chain molecular compounds were extremely important for the emergence of life on Earth because all living organisms are composed of the same chemical building blocks at the molecular level. Peptides are formed from individual amino acids and perform completely different functions in the body: whether it is to transport substances, speed up reactions or form anchoring frameworks in cells.

The search for the original is ongoing

Krasnokotsky supported the theory of cosmic peptides in a paper two years ago Stady, where researchers demonstrated chemical reactions that, under certain conditions, could lead to the formation of biological compounds. They likely originated in cosmic dust clouds, and from there were transported to Earth by meteorites, asteroids and comets. It also shows that peptides could be extraterrestrial in nature Amino acids, Nuclear bases And various sugars that have been discovered in meteorites in the past.

In order to further investigate this assumption, the astrophysicist, together with a German-French research team, simulated chemical reactions in the laboratory, which could have occurred in space billions of years ago. “It is, so to speak, a continuation of our previous investigations – but we are now able to analyze chemical reactions more precisely than before and show that only a small number of materials are needed.”

Results of experiments conducted in vacuum chambers, among others, which the research team is currently carrying out In the journal “Advance Science” The presentation shows that carbon (C), carbon monoxide (CO), and ammonia (NH3) were primarily necessary for the formation of biomolecular compounds. “All this is sufficiently present in molecular clouds in space,” says Krasnokotsky.

Facilitated cold calling

It is also possible that the extremely low temperatures in space contributed to the formation of the peptides. When molecular compounds are formed, water must actually be broken down into its individual parts, which usually requires very large amounts of energy. However, the extreme cold in cosmic dust clouds greatly reduces energy requirements, facilitating the formation of short-chain peptides.

In addition, due to the cold temperatures in space, other carbon molecules also attach to the materials that protect the peptides from the effects of ultraviolet radiation. “These compounds are usually very fragile and are quickly destroyed by UV photons, so the cold helps protect them from that,” says Krasnokotsky.

So does life on Earth really come from space? The astrophysicist believes this is likely, even if more studies are needed to definitively clarify the thesis.