Why does the Divine Proportion (Phi, golden section) appear in nature?

If you like Math and Art, or Math and Natural Sciences, it is very likely that you have heard about the Divine Proportion (Golden Section) http://goldennumber.net/ ,
http://homepage.cem.itesm.mx/lgomez/audio03/index.htm
The fact that the Divine Proportion (the number Phi=1.618…) is present in Art might not be so surprising, we could argue that is only a convention of western art, coming directly from the ancient Greeks.
However the number Phi=1.618… is also present in nature http://www.bbc.co.uk/radio4/science/5numbers3.shtml
Why? Why does this specific number appear everywhere in Nature? Is there something really “divine” about it?
The answer seems to be, at least in some cases, evolution: survival of the fittest. The geometrical structures that contain the number Phi=1.618… are usually the best structures in terms of “use of available space”, therefore plants and animals have evolved to have that kind of structures in their bodies, shells, seeds, etc.
Dr Ron Knott has written a very interesting page http://www.mcs.surrey.ac.uk/Personal/R.Knott/Fibonacci/fibnat2.html, go and search in that page the section with title “Why does Phi appear in plants?”. This page includes very interesting computer-generated animations explaining why Phi=1.618… is the best number for packing seeds. For those of you that like the computer program Mathematica, I think it would be great to recreate some of those animations in Mathematica, with the Manipulate command, and then send them to the “Wolfram Demonstrations Project” http://demonstrations.wolfram.com/, please let me know if someone does it.

Welcome

Welcome to my blog in English. I am a mexican mathematics teacher. I will use this blog to share some of the things I learn about Mathematics, Physics, Mathematica, Excel, Education, etc. I hope you will find here something interesting and useful.
Jose Luis Gomez-Munoz