Growth Morphology
Relevant parameters have macroscopic manifestations, even away from the extinction threshold:
The parameter λ indicates the dependence of growth velocity on slope.
While isotropic growth leads to λ=vo> 0, other growth rules (as in earlier model) lead to λ< 0
The evolution of the active fraction f may also affected by slope
(Neutral) sector 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 :