• A tree called Hevea brasiliensis is very good at this, producing a polymer called latex - natural rubber.
  

• Note the head-to-tail connections, as well as the stereochemistry
  • All of the double bonds in geranyl and farnesyl phosphates, and squalene, are trans-

  • Latex has all cis- double bonds. This stereochemistry results in a coiled structure for latex:
  

• The picture shows a tetramer, minimized with the MMX force field of PCModel

• The coiling is responsible for the elasticity of latex.

• A naturally occuring isomer of latex, called gutta percha, is all trans-; it is sufficiently hard and inelastic that it once was used to cover golf balls.

The conversion of squalene to sterols is carried out widely in nature. Here are a few examples:

The amyrins are found in latex from Hevea and other trees	Oleanic acid, as the acetate, is a constituent of birch bark
Ursolic acid is found in the natural wax on apples and other fruit	Fusidic acid is an antibacterial synthesized by Fusidium coccinium