Monday, 7 July 2014

Stanley Miller experiment revisited


It may surprise a number of people that not all of Stanley Millers prebiotic conditions experiments were analyzed. The most famous one is the experiment which produced amino acids which are the building blocks for proteins. However, Miller conducted many other experiments and recently there have been manuscripts reporting on the stored reaction mixtures of some of Millers other experiments. Surprisingly these experiments are just as interesting as his most famous experiment.

The news I want to focus on, is a recent report in Angewandte Chemie which has shown that in an experiment conducted by Miller in 1958 that dipeptides (two linked amino acids, important in many body parts) and diketopiperazines (important in natural drugs) formed under very simple conditions. What makes this interesting is that for this to happen Miller added another chemical. Amazingly this chemical he added can also form under early earth conditions and it is this chemical that makes these dipeptides form.

However, Parker and colleagues who conducted the analysis of the Miller solution were not happy to just believe Miller. They conducted the experiment again like all good scientists should. Not surprisingly they found the exact same thing. This shows (once again) that life beginning on Earth from basic chemicals is not such a miracle after all.

An ever big wow moment happened when these authors showed that these reactions can happen in conditions that are slightly basic in nature (pH about 9.5). Previously criticisms of these experiments have been that they require very acid conditions (pH about 1.5). If you don't know what pH is either look here, or understand that water has a pH of 7, coke is about 3. Basically, this glimmer of hope of creationists is now no longer a criticism of this experiment.

I love science.

Here is a video showing the lead author of this paper Eric Parker explaining the research.