Scientists at the Scripps Institute have proposed a new explanation for the origin of life on Earth. It turned out that the first living “organism” could be a self-replicating mixture of DNA and RNA, which arose as a result of simple chemical reactions. The results of the study are published in Angewandte Chemie International Edition and are summarized in a press release on Phys.org.
In the new work, the authors questioned the hypothesis of the RNA world, according to which the first replicators (structures capable of reproduction) were RNA molecules. In their opinion, the RNA was too “sticky” for the new strand created on its template to detach from the parent molecule. In modern organisms, proper replication is provided by special enzymes that were absent before the first living cells appeared.
However, chimeric molecules of DNA and RNA could circumvent this problem. Scientists have shown that a simple substance called diamidophosphate could link ribonucleosides (the building blocks of RNA) into long chains and do the same with DNA.
According to the researchers, the discovery will help develop new methods for the synthesis of RNA and DNA molecules without enzymes, the use of which is associated with costs due to their fragility and demanding conditions of detention.
