biological clocks, Forger,

Biological Clocks, Rhythms, and Oscillations

The Theory of Biological Timekeeping

Daniel B. Forger.

https://www.ncbi.nlm.nih.gov/books/NBK544607/ 

https://www.ncbi.nlm.nih.gov/books/NBK544607/pdf/Bookshelf_NBK544607.pdf

Forger said that many bio clock use the same mathematic equations (models). convergent evolution. Forger said that Hoff bifurcation seems to be the common cause in all biological clocks. 

J Tyson seems to have strong reservation on Forger's argument of evolution of the general math equation. 

General structure of clocks. 

not all bacteria has circadian clocks.