Microscopic dissipative structuring and proliferation at the origin of life

Area of Science:

• Astrobiology
• Origin of Life Studies
• Biochemistry

Background:

• The early Earth's Archean surface was bathed in UV-C and UV-B radiation.
• Photochemical reactions are proposed as a mechanism for early life's molecular origins.
• Dissipative structuring and autocatalysis are key concepts in non-equilibrium thermodynamics.

Purpose of the Study:

• To explore the role of UV radiation in the formation and evolution of fundamental life molecules.
• To investigate photochemical microscopic dissipative structuring and autocatalytic proliferation.
• To provide a thermodynamic-dissipation perspective on the origin of life.

Main Methods:

• Analysis of molecular characteristics, including UV absorption and excited state decay pathways.
• Examination of purine formation from hydrogen cyanide under UV-C irradiation.
• Investigation of single-strand DNA production via UV-C-induced phosphorylation and denaturation of nucleic acids.

Main Results:

• Purines can form from hydrogen cyanide via UV-C-induced isomerizations and tautomerizations in water.
• Single-strand DNA can proliferate through UV-C-induced phosphorylation and denaturation of RNA and DNA.
• Molecules exhibit strong UV absorption and rapid excited-state decay via conical intersections.

Conclusions:

• Photochemical processes under Archean UV conditions provide a physical-chemical basis for life's origins.
• Dissipative structuring and autocatalysis offer a thermodynamic framework for understanding early molecular evolution.
• UV-driven reactions were critical for forming and proliferating key biomolecules like purines and DNA.