Contingency in biology

One of the late Stephen Jay Gould's regular observations was that the evolution of life on Earth has been highly contingent. Minor, often random, events in life's history have reverberated throughout the eons. One of the many fatal flaws of the "specified complexity," Billy Dembski's idea for proving design, is that it circularly assumes that the way things are is exactly the way that a "designer" would want them to be. This idea ignores the oddly contingent course life has taken over the last 3.8 billion years.

Chemists have illuminated one such contingent path that life took:

Chemists at Yale have done what Mother Nature chose not to — make a protein-like molecule out of non-natural building blocks, according to a report featured early online in the Journal of the American Chemical Society.

Nature uses alpha-amino acid building blocks to assemble the proteins that make life as we know it possible. Chemists at Yale now report evidence that nature could have used a different building block – beta-amino acids — and show that peptides assembled from beta-amino acids can fold into structures much like natural protein.

We have no idea how life would be different if the building blocks of proteins were different. The scientists think proteins made of beta-amino acids may work as well as, or even better than, naturally occurring alpha-amino acids.

Gould commented in Urchin in the Storm that "Chance and historical contingency give the world of life most of its glory and fascination." Never has that been clearer.