Migration

Implementation of migration follows the “stepping stone” model. The proportion of migrants was arbitrary chosen to m = 1 / 2 . The half of randomly chosen individuals in deme is split equally to fractions migrating to the all neighboring demes (Figure 3.5).

On following schemes the full migration model is visualized for deme with index one. Each square represents one deme. Half of every deme is split to equally sized parts and migrates to neighboring demes every generation. The same number of immigrants arrive from neighbors.

Scheme for the chain of demes (dimension is 1).

Scheme for the mail of demes (dimension is 2).

Migration of zero-dimensional simulation is represented by constant amount of alien individuals (B) incoming to the home population (A). In simulation is this constant set by parameter DEMEsize since it loses its original meaning if space is not simulated.