Thursday, November 17, 2005

Update on Primordial Soup

One of the good things about the public debate about Intelligent Design is the introduction of the term testable hypothesis into common usage.  The idea is that a scientific theory should generate testable hypotheses.  That is, it should be possible to use the theory to make guesses about what one would find, if certain experiments were done.  If the experiments are done, and the results conform to the guesses, then the theory is strengthened.  If the guess turn out to have been wrong, the theory is weakened.  The overall validity of the theory is determined by the accuracy of the guesses.  

Evolutionary Theory predicts that experiments done under primitive geological conditions should show that it would have been possible for certain organic molecules to be formed.  Note that there is no single experiment that can be done that would prove or disprove the entire Theory.  That is not the point.  The point is to do the experiments, see what happens, and continue to modify the Theory as indicated by the results of the experiments.  Just like evolution itself, the scientific method has no predefined endpoint.  

Those who misunderstand evolution often believe that evolution progresses to some kind of ideal endpoint, as though some mysterious is guiding the organisms to mate in such a way as to produce offspring that are "better" in some way.  That is not the case.   Organisms do what they do, and what happens, happens.  If what happens works, then more of it happens.  Theories evolve in much the same way.  Sometimes they reach a dead end, when experiments repeatedly show that the hypotheses are fruitless.  

Now, Arizona State University geochemists, led by Lynda Williams, have added another notch in the stock of Evolution:
Williams' research suggests how some of the fundamental materials necessary for life might have come into existence deep in the sea. The results of Williams' experiments were published in the article, "Organic Molecules Formed in a Primordial Womb," in the November issue of Geology.

Williams and her team mimicked the conditions found in hydrothermal vents along the lines where tectonic plates converge on the ocean floor. The vents are fissures in the seafloor that spew out super-hot water much like an underwater volcano. [...]

Williams hypothesized that the expandable clay surrounding the hydrothermal vents might have served as a "primordial womb" for infant molecules, sheltering them within its mineral layers. She devised an experiment that would test whether the organic compound methanol would be protected between the clay layers.

Williams and her team simulated the intense heat and pressure of the ocean floor within a pressurized vessel. The reaction of the clay and methanol was monitored over six weeks. The team found that the expandable clay not only protected the methanol, but also promoted reactions that formed even more complex organic compounds. The mineralogical reaction between the clay and methanol was facilitating the production of new organic material. [...]
This is not a really big deal.  It is pretty much what we expected.  Was is notable is that, while scientists continue to make notches in the stock of , practitioners are still looking for their first testable hypothesis.  One reason they are stymied is this:  Implicit in their theory is the belief that the things we see around us in the world, are so complex that they could not have been formed by evolution.  In order to find experimental evidence of that, they have to come up with experiments to show that evolution could not have produced the organisms we see.  That's a tough one.