The Complexity of Life’s Origins

A Physicochemical View

Authored by: Jan J. Spitzer

Handbook of Astrobiology

Print publication date:  December  2018
Online publication date:  December  2018

Print ISBN: 9781138065123
eBook ISBN: 9781315159966
Adobe ISBN:

10.1201/b22230-32

 Download Chapter

 

Abstract

First cells in vivo (the last universal common ancestors, or LUCAs) were as complex as extant prokaryotic cells: multiphase, multicomponent, molecularly crowded, in cyclic disequilibrium, and re-emergent—with biochemistries comparable to those of today’s prokaryotes. The evolution of complexity can be framed as a jigsaw puzzle of chemical reactions, colloidal phase separations and geochemical consolidations, driven by planetary cycles of diurnal temperatures and tidal (seawater) hydrations-dehydrations. The physicochemical nature of the jigsaw puzzles affords new insights into the problem of life’s emergence: Schrödinger’s putative physical laws of life are unnecessary; cycling phase separations bring about evolutionary chemical purifications of Earth’s complex (“tarry”) prebiotic chemistry toward simpler biochemistry of all life; abiotic/biotic transitions arise when non-covalent molecular forces (biomacromolecular crowding, hydration, and screened electrostatic forces) become commensurate at about one nanometer, allowing the evolution of molecular recognition (genetics, metabolism, and cellular self-organization); cyclic fusions of cells and of cells with environmental nucleic acids generate evolutionary saltations (natural genetic engineering); and the physicochemical jigsaw puzzle explains biological terms such as becoming alive, being alive (or dead), and being alive and evolving. Specific but challenging experiments in the chemical bottom-up and microbiological top-down paradigms are suggested; they are based on “self-purifying” complex chemical mixtures that evolve under cyclic (PCR-like) processes.

 Cite
Search for more...
Back to top

Use of cookies on this website

We are using cookies to provide statistics that help us give you the best experience of our site. You can find out more in our Privacy Policy. By continuing to use the site you are agreeing to our use of cookies.