Mais uma hipótese sobre a origem da vida: a físico-química muda o paradigma. Será???

terça-feira, junho 16, 2015

Emergence of life: Physical chemistry changes the paradigm

Jan Spitzer 1, Gary J. Pielak 2 and Bert Poolman 3

Corresponding authors: Jan Spitzer jspitz@mcpolymers.com - Gary J Pielak gary_pielak@unc.edu - Bert Poolman b.poolman@rug.nl

Author Affiliations

1 R&D Department, Mallard Creek Polymers, Inc., 2800 Morehead Rd, Charlotte 28262, NC, USA

2 Department of Chemistry, Department of Biochemistry and Biophysics and Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill 27599, NC, USA

3 Department of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute & Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, Groningen, 9747, AG, The Netherlands

Biology Direct 2015, 10:33 doi:10.1186/s13062-015-0060-y

Received: 9 February 2015

Accepted: 14 May 2015

Published: 10 June 2015

© 2015 Spitzer et al. 

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver
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Abstract

Origin of life research has been slow to advance not only because of its complex evolutionary nature (Franklin Harold: In Search of Cell History, 2014) but also because of the lack of agreement on fundamental concepts, including the question of ‘what is life?’. To re-energize the research and define a new experimental paradigm, we advance four premises to better understand the physicochemical complexities of life’s emergence:

(1) Chemical and Darwinian (biological) evolutions are distinct, but become continuous with the appearance of heredity.

(2) Earth’s chemical evolution is driven by energies of cycling (diurnal) disequilibria and by energies of hydrothermal vents.

(3) Earth’s overall chemical complexity must be high at the origin of life for a subset of (complex) chemicals to phase separate and evolve into living states.

(4) Macromolecular crowding in aqueous electrolytes under confined conditions enables evolution of molecular recognition and cellular self-organization.

We discuss these premises in relation to current ‘constructive’ (non-evolutionary) paradigm of origins research – the process of complexification of chemical matter ‘from the simple to the complex’. This paradigm artificially avoids planetary chemical complexity and the natural tendency of molecular compositions toward maximum disorder embodied in the second law of thermodynamics. Our four premises suggest an empirical program of experiments involving complex chemical compositions under cycling gradients of temperature, water activity and electromagnetic radiation.

Keywords: Chemical evolution; Darwinian evolution; Origin of life; Diurnal gradients; Chemical complexity; Biomacromolecular crowding; Non-covalent intermolecular forces; Molecular recognition; Cellular organization

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