  We study the shape dynamics of a two-component fluid membrane, using a
dynamical triangulation monte carlo simulation and a Langevin description.
Phase separation induces morphology changes depending on the lateral mobility
of the lipids. When the mobility is large, the familiar labyrinthine spinodal
pattern is linearly unstable to undulation fluctuations and breaks up into
buds, which move towards each other and merge. For low mobilities, the membrane
responds elastically at short times, preferring to buckle locally, resulting in
a crinkled surface.
