Growth Morphology
Relevant parameters have macroscopic manifestations, even away from the extinction threshold:
The parameter λ indicates the dependence of growth velocity on slope
The evolution of the active fraction f may also affected by slope
Domain boundaries should generically drift on a sloped substrate
The extinction point can itself depend on slope or curvature
The shape of the front is modified if one species expands more than the other:
Two different morphologies depending on the sign of λ :