The stepwise evolution of early life driven by energy conservation

Area of Science:

• * Origin of Life Research
• * Cellular Evolution
• * Biochemistry

Background:

• * Current theories on life's origin focus on heterotrophic or chemoautotrophic metabolisms with limited common ground.
• * The role of carbon monoxide (CO) is acknowledged but not central to existing paradigms.
• * Genomic analysis of archaea provides insights into early metabolic pathways.

Purpose of the Study:

• * To propose an alternative theory for early cell evolution that unifies existing, disparate theories.
• * To highlight the role of energy conservation pathways in directing cellular evolution.
• * To explain the origin and evolution of methanogenic pathways.

Main Methods:

• * Genomic analysis of the archaeon Methanosarcina acetivorans.
• * Deduction of the extant pathway for the conversion of carbon monoxide (CO) to methane and acetate.
• * Theoretical modeling of early energy conservation pathways.

Main Results:

• * A novel theory integrating key features of heterotrophic and chemoautotrophic origins of life.
• * Identification of an energy-conservation pathway as a primary driver of early cell evolution.
• * A proposed timeline for the development of energy conservation prior to diverse protein-based metabolisms.

Conclusions:

• * Energy conservation pathways, rather than solely metabolic types, were pivotal in early cell evolution.
• * This unified theory reconciles existing hypotheses on the origin of life.
• * The proposed framework explains the evolution of extant methanogenic pathways.