Protocells, the origins of life, and the RNA World

November 9, 2008

This essay is a bit less formal than many I’ve posted here, more of an indulgence than the cut-and-dried stuff I’ve been posting about polyadenylation. It is essentially a repost of an essay I posted on the old ARN boards many years ago. I’m moved to this by a recent a recent article in PNAS. The overall context is the origin of life, and some of the different arguments and perspectives that are brought to the table in ev/cre debates.

As a segue, the abstract of the PNAS article:

“Life is that which replicates and evolves. The origin of life is also the origin of evolution. A fundamental question is when do chemical kinetics become evolutionary dynamics? Here, we formulate a general mathematical theory for the origin of evolution. All known life on earth is based on biological polymers, which act as information carriers and catalysts. Therefore, any theory for the origin of life must address the emergence of such a system. We describe prelife as an alphabet of active monomers that form random polymers. Prelife is a generative system that can produce information. Prevolutionary dynamics have selection and mutation, but no replication. Life marches in with the ability of replication: Polymers act as templates for their own reproduction. Prelife is a scaffold that builds life. Yet, there is competition between life and prelife. There is a phase transition: If the effective replication rate exceeds a critical value, then life outcompetes prelife. Replication is not a prerequisite for selection, but instead, there can be selection for replication. Mutation leads to an error threshold between life and prelife.”

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Reasons for optimism

November 9, 2008

A favorite blogger of mine comments on Millennials, the recent election, and the future.  Needless to say, one can see reasons for optimism.  Enjoy.

On the Origins of Life and The RNA World

November 9, 2008

On The Panda’s Thumb, Ian Musgrave has an interesting entry on the origins of life and the RNA World – it traces back to this ScienceBlogs essay.  Apropos of this, a nice publication came across my RSS feed late last week.  This study reveals that one of the chemical functionalities that catalyzes the charging of a tRNA is provided by the tRNA substrate itself.  The abstract, and brief commentary, are after the fold.  As always, enjoy. Read the rest of this entry »