[meteorite-list] How Did Earth's Primitive Chemistry Get Kick Started?

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Tue, 30 Jul 2013 13:51:33 -0700 (PDT)
Message-ID: <201307302051.r6UKpXdv021166_at_zagami.jpl.nasa.gov>


How Did Earth's Primitive Chemistry Get Kick Started?
Jet Propulsion Laboratory
July 30, 2013

How did life on Earth get started? Three new papers co-authored by Mike
Russell, a research scientist at NASA's Jet Propulsion Laboratory,
Pasadena, Calif., strengthen the case that Earth's first life began at
alkaline hydrothermal vents at the bottom of oceans. Scientists are
interested in understanding early life on Earth because if we ever hope
to find life on other worlds -- especially icy worlds with subsurface
oceans such as Jupiter's moon Europa and Saturn's Enceladus -- we need
to know what chemical signatures to look for.

Two papers published recently in the journal Philosophical Transactions
of the Royal Society B provide more detail on the chemical and precursor
metabolic reactions that have to take place to pave the pathway for
life. Russell and his co-authors describe how the interactions between
the earliest oceans and alkaline hydrothermal fluids likely produced
acetate (comparable to vinegar). The acetate is a product of methane and
hydrogen from the alkaline hydrothermal vents and carbon dioxide
dissolved in the surrounding ocean. Once this early chemical pathway was
forged, acetate could become the basis of other biological molecules.
They also describe how two kinds of "nano-engines" that create organic
carbon and polymers -- energy currency of the first cells -- could have
been assembled from inorganic minerals.

A paper published in the journal Biochimica et Biophysica Acta analyzes
the structural similarity between the most ancient enzymes of life and
minerals precipitated at these alkaline vents, an indication that the
first life didn't have to invent its first catalysts and engines.

"Our work on alkaline hot springs on the ocean floor makes what we
believe is the most plausible case for the origin of the life's building
blocks and its energy supply," Russell said. "Our hypothesis is
testable, has the right assortment of ingredients and obeys the laws of

Russell's work was funded by the NASA Astrobiology Institute through the
Icy Worlds team based at JPL, a division of the California Institute of
Technology, Pasadena. The NASA Astrobiology Institute, based at NASA's
Ames Research Center, Moffett Field, Calif., is a partnership among
NASA, 15 U.S. teams and 13 international consortia. The Institute is
part of NASA's astrobiology program, which supports research into the
origin, evolution, distribution and future of life on Earth and the
potential for life elsewhere.

Jia-Rui C. Cook 818-354-0850
Jet Propulsion Laboratory, Pasadena, Calif.
jccook at jpl.nasa.gov

Received on Tue 30 Jul 2013 04:51:33 PM PDT

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