On the Origin of Information Dynamics in Early Life
Robert A. Gatenby, Jill A. Gallaher, Hemachander Subramanian, Emma U. Hammarlund, Christopher J. Whelan · Preprints.org · 2024
We hypothesize that predictable variation in environmental conditions caused by day/night cycles create opportunities and hazards, initiating information dynamics central to life’s origin. Increased daytime temperatures accelerated key chemical reactions but caused separation of double stranded polynucleotides, leading to hydrolysis, particularly of single-stranded RNA. Daytime solar UV radiation promoted synthesis of organic molecules but caused broad damage to proto-cell macromolecules. We hypothesize inter-related, simultaneous adaptations to these hazards produced molecular dynamics necessary to store and use information. Self-replicating RNA heritably reduced hydrolysis of single strands after separation during warmer daytime promoted sequences that formed hairpin loops generating precursors to transfer RNA (tRNA). Proto-cell survival during daytime promoted selection for sequences in entrapped, self-replicating RNA that formed RNA-peptide hybrids capable of scavenging UV-induced free radicals or catalyzing melanin synthesis from tyrosine. We hypothesize these dynamics resulted in diurnal rhythms ubiquitous in extant life and provided precursors leading to RNA directed protein synthesis. Adaptation mitigating UV damage in early life led to homochirality and replacement of Na+ by K+ as the dominant mobile cytoplasmic cation. We conclude information dynamics emerged in early life through adaptations to predictably fluctuating opportunities and hazards during day/night cycles. These dynamics includes properties observed in extant life.