JTW's Evolutionary Origins - Author: Wood, John T.

Recent Excitement In The Search For The Origin of Life

Recently a debate has been brewing.

The, once tranquil, field of pre-biotic chemistry has been taken to task by an outsider.

Cherished ideas, vested interests, and lifetimes of work are being challenged.

Origin of life researchers find themselves embroiled in a battle, possibly a war, with, of all things, a patent lawyer.

To be fair, Gunter Wachtershauser is also an organic chemist with a Ph.D. from Marburg University in Germany (1965), but until 1988, it had been 22 years since his last scientific publication.

Now, a little over a decade after he reentered the scientific arena, he is poised to transform the way scientist approach to the experimental and theoretical questions surrounding life's origin.

A revolution is under way and insiders don't like it, or rather wish that change had come from someone inside the field - certianly not from the likes of a professional lawyer.

To be sure, there are plenty of other competing interests, some getting more notice (and money) than others.

Adherents of the pre-biotic "soup" model of origins are as vocal and active as ever.

They have defined the field since it's inception and many have achieved legendary status within the annals of science.

It is they who have the most to lose, hence their intrepidation with Wachtershauser and his theory.

Ultimately though, without the work of the prebiotic "soup" researchers and theoreticians, the insights of Wachtershauser would be without context - hence they have performed an invaluable service and their contributions are not without merit, regardless of weather their work stands or falls in the long run.

Another are of burgeoning interest is that of Exobiology, primarily driven by the astronomical juggernaut that is NASA and it's fellow space exploration partners.

Within this camp, one can discern at least two major factions.

One group of researchers sees space as a source of energy-rich organic compounds for stocking the Earth's early oceans, thereby enriching the primordial "broth".

These researchers represent an extension of the old school into space.

The second group also has historical precedent, going as far back as Svante Arrhenius and his 1907 opus, "Worlds in the Making".

These researchers seek to find the "seeds" of life on Earth, out in space - Panspermia.

The approach of the first faction is a sensible and practical approach based on current knowledge and theory within the origin of life field.

Space is a natural place to look for a source of material influx into the planetary system.

David Deamer has commented that every year enough organic material falls to Earth sufficient to cover the entire planetary surface with a layer of material � inch thick.

During, and for quite awhile after, the Earth's formation this quantity of organic matter was considerably greater.

At this time there was enough of an influx of organic material to produce a layer that was a least as deep as a room is high, across the Earth's entire surface.

The second approach appears to be more grounded in a longstanding hope that humanity, and the rest of our biological family, are not alone in the universe.

At best, success by this approach will only move the questions surrounding life's origin to a new locale in the universe.

It would provide few clues as to the actual nature of the origin event.

While the second approach appears to be less justified on the basis of known data, it's emotional, spiritual, and political valence may actually be helping to attract the support and funding necessary to carry out the work of the first faction.

Back on Earth, assuming we place the origin event at home, there are internal squabbles and differences of opinion.

Metabolism first? Or genes first? Proteins or nucleic acids ? RNA World? Thioester World? Lipid World? Chemoautotrophic, photoautotrophic, or heterotrophic progenote?

After more than 20 years of incubation, Wachtershauser was encouraged by his friends, the philospher of science, Karl Popper, and the eminent microbiologist, Carl Woese to publish his ideas.

Between 1988 and 1992, Wachtershauser published several major articles detailing his theory of life's origins in an "Iron-Sulphur World".

In February of 1988, with the help of Popper, Wachtershauser's first paper in more than 20 years was published, proposing "An all-purine precursor to nucleic acids".

Later that year, he published his hypothesis of an iron sulphide / hydrogen sulfide to pyrite redox couple as a primordial energy source.

In December of that year he also published an article hypothesizing the "Surface Metabolist" as the primitive organizational morphology of life.

In 1990 he followed up with a paper that proposed that analogs of the Reductive Citric Acid Cycle (RCC) might serve as the primitive autocatalytic core of biochemistry (1990a).

The next year, he offered a hypothesis postulating the chiral synthesis of biomolecules on a pyrite surface.

And in 1992, Wachtershauser published his most comprehensive treatment of the subject to date, "Evolutionary Biochemistry: The Iron-Sulphur World".

In this publication he developed and integrated his theoretical ideas and laid the foundations for a new approach to understanding biochemical structures in relation to life's origin.

The ideal environment setting was proposed to be localized regions within hydrothermal vents systems under high temperature and pressure conditions, such as those found relatively recently (compared to the age of the OOL field) at the bottom of the oceans.

"Dr. Wachtershauser, we're no patent lawyers here."

Chistian De Duve (1974 Nobel Prize Winner in Medicine and Physiology "for their discoveries concerning the structural and functional organization of the cell.")

During this time, Wachtershauser had begun to stir up the OOL field.

Insiders accused him of employing a theoretical "paper chemistry", saying that there was no experimental proof for his ideas.

Not suprising as Wachtershauser had no lab in which to perform the necessary experiments.

Many felt that Wachtershauser being a lawyer, should stay a lawyer and leave questions regarding life's origin to the experts and experimentalists.

Nonetheless, Wachtershauser's theory began to change the way OOL researchers thought about the problem and set in play an understanding that more comprehensive standards of explanation (compared to the requirements of broth theories) would have to be met if a coherent theory of lifes origins was to be constructed.

The appeal of Wachtershauser's theory is that it attempted to derive an understanding of biochemical structures and relationships by elucidating specific evolutionary mechanisms by which these structures may have emerged.

"Autocatalysis is the chemical expression for reproduction, one of the key features and, hence, maybe the first form of life."

Gunter Wachtershauser

Since his initial foray into the field, Wachtershauser has been busy rebutting critics and naysayers; as well as, pursuing experimental support for his ideas, with several collaborators, within a laboratory context.

Two key accomplices in these endeavors were the microbiologist, Karl O Stetter and the chemist, Claudia Huber, both originally from the University of Regensburg, Germany (O Stetter and Wachtershauser have since parted ways and Huber is now directly in the employ of Wachtershauser).

Throughout the 1990's Wachtershauser and his associates set about to test the various aspects of the theory.

One reaction at a time, they managed to confirm several of the previously hypothetical reactions.

By August of 2000, things were looking up for Wachtershauser.

It was a this time that George D. Cody and colleagues published an article in Science detailing their experimental synthesis of pyruvate using carbonylated iron-sulfur compounds.

Pyruvate, Wachtershauser believes, is a key player in his postulated auto-catalytic core, the RCC.

This experimental demonstration completed a sequence of reactions leading from carbon monoxide (CO) and/or carbon dioxide to oligopeptide formation.

A tentative version of this reaction sequence was postulated by Wachtershauser on the basis of theoretical considerations.

Up until August 2000, he and his associates had been diligently working towards finding experimental support for these reactions.

In 2001, Wachtershauser's proposal for hyperthermophilic origins received a boost when evidence was presented by a team of collaborators lead by geologist Simon Wilde of Curtin University of Technology in Perth, Australia showing that hot primodial oceans with subsea volcanic activity may have existed as early as 4.4 BYA.

Taken togetner with Cody et al.'s synthesis of pyruvate under high-temperature and high-pressure conditions, Wachtershauser began to receive more than just attention.

He started to receive funding.

Germany's DFG funding agency allocated $500,000 in the form of four research grants to Wachtershauser recently.

[Validate This Page]