Rethinking the Last Universal Common Ancestor of Life: Network Convergence and the Root of the Tree

Area of Science:

• Origin of Life Studies
• Biochemistry
• Evolutionary Biology

Background:

• The origin of life remains a fundamental question in science.
• One model suggests core biochemistry arose from a single origin, a 'frozen accident'.
• An alternative model proposes diverse biochemistries emerged and converged.

Purpose of the Study:

• To explore an alternative model for the evolution of core biochemistry.
• To investigate the role of the 'network effect' in biochemical convergence.
• To re-evaluate the nature of the Last Universal Common Ancestor (LUCA).

Main Methods:

• Theoretical modeling of biochemical evolution.
• Analysis of the 'network effect' in biological systems.
• Comparison of model predictions with observational data.

Main Results:

• The network effect drove convergence of diverse biochemistries.
• LUCA is proposed as a process of convergence, not a single organism.
• Biochemical evolution was driven by compatibility and coordination.

Conclusions:

• Core biochemistry may be a result of evolutionary optimization, not just a 'frozen accident'.
• Evidence suggests molecular entanglement and coevolution in core biochemistry.
• Biosynthetic pathways appear to differ from prebiotic chemistry, supporting the proposed model.