Invasion speed
Morphologies for isotropic growth of a more fit mutant:
How rapidly does the mutant invade the wild type?
The faster of the uncoupled Fisher velocity, or circular arc velocity, determines invasion speed!
This is likely due to the simple form of competition rule leading to a "pulled" Fisher waves.
Preliminary results in a modified ("Allee") competitive model leading to"pushed" Fisher waves.
Speed of the fitter species can actually be reversed by the growth advantage of the less fit species.
Combining exact solution of the modified Fisher equation with the Cole-Hopf transformation via perturbation theory
enables computation of the modified wave-velocity in a small gradient expansion.