Are Shell Spirals "Merely" Works of Physics?

A statement from CNRS, the French National Centre for Scientific Research, touts research in the Journal of Theoretical Biology. The news release states flatly, "Physics determined ammonite shell shape." It goes on to say that, even though individual shells of different species are "exceptionally diverse," they can all be explained by a biomechanical model.

"Their approach provides new paths for interpreting the evolution of ammonites and nautili," the article boasts. What's missing in this...