The Life & Mind Seminar Network

Seminar #49: A Metabolic Error Threshold

Posted in Seminars by Tom Froese on February 23, 2009

This week we will have an informal discussion group led by Chrisantha
Fernando. The discussion topic will be:

A Metabolic Error Threshold

Chrisantha Fernando

Time: 4:30-6:00pm
Date: Wednesday, 25th February
Location: Pev. 1, room 2A03

The problem of the origin of metabolism is unsolved. How could a metabolism arise that was capable of producing nucleotides? I will briefly present my early work on this question that proposed chemical evolution by natural selection between compartments enclosing a messy generative metabolism (1-2). The models have not had the impact I would have liked. I think this is because they use a 1+1 ES with elitism rather than a population model, and the chemical model is not parameterized with sufficient generality for chemists.

I discuss an idea for a new paper describing a re-design of this model along the lines of a paper about a later problem in the origin of life, that of information integration by cooperating templates by either Hypercycles or the Stochastic Corrector Model (3). The metabolic error threshold is the rate at which side reactions can be produced without destroying the autocatalytic core. The new model is intended to describe how this factor is critical in the origin of metabolism, and to provide stronger evidence for the conditions in which metabolic heredity can arise.

References:

1. Fernando, C. and Rowe, J. (2007a) Natural Selection in Chemical
Evolution. Journal of Theoretical Biology, 247:152-167

See supplementary material here:
http://www.cogs.susx.ac.uk/users/ctf20/dphil_2005/ChemicalEvolution.htm.
Submitted paper here:
http://www.cogs.susx.ac.uk/users/ctf20/dphil_2005/Publications/JTB-S-06-00798-1.fdf
Final version here:
http://www.cogs.susx.ac.uk/users/ctf20/dphil_2005/Publications/JTB2007.pdf

2. Fernando, C. and Rowe, J. (2007b) The Origin of Autonomous Agents, Biosystems, Special Issue on Autonomy. Eds. Kepa
Ruiz-Mirazo & Xabier Barandieran.

Download draft doc file here:
http://www.cogs.susx.ac.uk/users/ctf20/dphil_2005/Publications/BiosystemsSubmissionFinalApril2007.doc
See supplementary material here:
http://www.cogs.susx.ac.uk/users/ctf20/dphil_2005/ChemicalEvolution.htm
Download proof here:
http://www.cogs.susx.ac.uk/users/ctf20/dphil_2005/Publications/BIO_2762ProofCorrections.pdf

3. ELIAS ZINTZARAS, MAURO SANTOS and EÖRS SZATHMÁRY. “Living” Under the Challenge of Information Decay: The Stochastic
Corrector Model vs. Hypercycles. Journal of Theoretical Biology. Volume 217, Issue 2, 21 July 2002, Pages 167-181

download,

All welcome!

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