Did Crystal Power Make Proteins Southpaws? 05/01/2001
NASA astrobiologists have published a paper in the Proceedings of the National Academy of Sciences on experimental evidence that calcite crystals and other minerals might selectively concentrate left- and right-handed amino acids (click here for summaries in Scientific American or Nature. NASA’s Astrobiology Site also has a lay-audience version of the story.) All living organisms incorporate only left-handed amino acids into their protein chains; the choice of left or right appears to be arbitrary, but life depends on 100% of one hand or the other. In these experiments, the team achieved yields of just under 10% preference for one hand. This is significant for origin of life scenarios, the paper concludes, because minerals could have not only concentrated one hand over the other but also arranged them into chains.
Another weak, weak attempt to explain the mystery of the left-handed proteins. This “what-if maybe perhaps” scenario doesn’t come close to jumping over this major hurdle to abiogenesis. Only 100% yield will produce peptide chains with any useful enzymatic activity. Also, amino acids do not naturally join together, even if adjacent; it requires energy to link them into polypeptide chains. Thirdly, only some of the simplest amino acids (aspartic acid, alanine) showed the slight selectivity; others did not. Fourthly, their theory requires wet-and-dry cycles, presumably on land or near the surface, where ingredients would be scarce and deadly UV radiation would be lethal - and it also contradicts other evolutionists’ beliefs that life arose near deep sea vents. Lastly, and most important, this has nothing to do with the major problem, the origin of information. As Phillip Johnson says, evolutionists always like to talk about the origin of the chemicals; when you force them to talk about the origin of information, that’s their downfall.