It is noted that high-energy particles that penetrate the planet’s atmosphere could affect protoorganisms, forcing them to develop homochirality inherent in all modern living organisms or the same chirality.
Chirality is the property of a molecule to form two forms that relate to each other as mirror images. In order for this property to manifest itself, a chiral center of the molecule is required — an atom with several substituents. Such a center exists in DNA, RNA, and amino acids. In living organisms, compounds are homochiral, that is, they are presented in a single chiral form, and when a mirror isomer of this compound is introduced into the body, it will not fulfill its function, and all biological processes involving this molecule will proceed differently.
The researchers suggested that cosmic rays led to homochirality, namely muons – the magnetically polarized residual particles of rays that scatter in the atmosphere. These particles exist only two millionths of a second, after which they decay into electrons with the same magnetic orientation.
According to the authors of the scientific work, the penetrating ability of muons and their daughter electrons could affect the chiral molecules on Earth. So, they say, initially cosmic radiation had a different effect on the evolution of two chiral forms of molecules, which is why one of them began to prevail over the other. Thus, right-handed DNA and RNA evolved at a faster rate and became more stable and suitable for living organisms.