Darwin's evolution needs to drink its milk

From Dan and Michele Hogan in the C-J...

The Cambrian Explosion more than 500 million years ago is regarded as one of the most relevant episodes in the history of life on Earth, when the vast majority of animal phyla first appeared in the fossil record.

However, the causes of its origin have been the subject of debate for decades, and the question of what was the trigger for the single-cell micro-organisms to assemble and organize into multi-cellular organisms has remained unanswered.

Scientists Xavier Fernàndez-Busquets of Barcelona, Spain, and Dario Anselmetti of Bielefeld, Germany, and colleagues published in the online journal Molecular Biology and Evolution the results of their investigation into biophysical single-molecule results of the effect of calcium on the interactions of cell adhesion molecules from marine sponges....

The researchers believe that a massive and sudden surge in the calcium concentration of the Cambrian sea water — believed to be the result of volcanically active mid-ocean ridges — not only initiated the buildup of calcified shells but also was mandatory for the aggregation and stabilization of multi-cellular sponge structures.

Darwin reckoned that there may have been long and hidden periods of animal evolution before the Cambrian Explosion, Xiao said. But paleontologists have not found such evidence, and recently scientists have learned that biological evolution has not been moving on a smooth road....

This reminds me of the speculations of Stephen Jay Gould-- in favor of "punctuated equilibrium", an idea that militates against the gradual change speculated by Darwin.