Animating Vectors in AE

AI
In Ai make a shape, and animate the second version. make sure the shape is a solid clean vector. Use the Shape Builder Tool for cleaning it up.

On a solid, first make a mask, then past the copied shape from AI, keyframe and copy in again

Set first vertex on the two different mask shapes

http://tv.adobe.com/watch/no-stupid-questions-with-colin-smith/creating-organic-animations-using-illustrator-paths-in-after-effects/