Skip to content

The Origin of Life Through Organic Chemistry

2015-03-16

On the primitive waters of Earth before life began almost four billion years ago, two chemicals, hydrogen sulfide and hydrogen cyanide, formed critical molecules of RNA and DNA.  With the addition of phosphates, all the necessary molecules of protein and lipids were formed.  The first step was a complex chain of reactions that branched out by exposure to ultraviolet light; then precursors of amino acids and lipids appeared.  Hydrogen sulfide was used as a reducing agent to polymerize carbon from hydrogen cyanide, and phosphates carried energy.  Copper ions were used to photoreduce multiple carbon-hydrogen bonds.  The resulting reactions form a complex, circular set of paths that produce ribonucleotides, amino acids, and lipids.  All these elements worked together as a mixed set to produce the precursors of living cells.

The research article that hypothesizes these reactions was characterized as a home run by observers.

“This is one of the best, most complete and most thoughtful papers ever written about how the building blocks could have formed,” says chemist Doron Lancet of the Weizmann Institute of Science in Rehovot, Israel.  But the next step, the assembly, is really the crux of the origins of life mystery, he says. “The paper lays a solid foundation of the first step so that we can free our minds to think about the second step”.

The article is in Science News, so you have to have a subscription to read it.  The abstract for the original research is in Nature Chemistry, at:   http://www.nature.com/nchem/journal/vaop/ncurrent/full/nchem.2202.html

The point, though, of the article, is that the simultaneous presence of multiple reactive pathways sets the stage for complex networks that evolve into life eventually.  Previously, most origin of life researchers had looked at individual pathways in isolation, without considering the possibilities of multiple pathways together.  Now, the multiple view makes the process easier to explain.

There has been considerable speculation of late about the ability of networks to evolve if allowed to reproduce with variations.  Such primitive systems can be compared productively to the way life evolves.  The only thing missing is the biological version of these primitive networks.

There should be an expedition to one of the worlds known to contain water in order to see if there is any life.  A salt water ocean seems like an ideal place for life to appear, according to current theories.  So far seven separate worlds in the solar system are known to have water.

Advertisements
No comments yet

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: