Stephen Z. Fadem, M. D.

1. Chordates radiated out and then calcified, telling us two things - that the enzymes are already present in each cell prior to radiation and that there must have been some environmental event that made calcification happen.
2. Those tissues that became precursors to the kidney arise from either mesodermal or ectodermal cells, depending upon whether or not the animal was a chordate. This means that the abity to protect and balance with ones environment was also primitive to the appearance of calcification
3. The appearance of calcification was to paleontology what the papyrus was to history.