Table 1.

Summary of the model parameters

Fixed parameters

Number of nonplastic, plastic, and dispersal loci = 1 each

Length of the environmental gradient = 50 demes

Steepness of the gradient (change in optimum in adjacent demes) = 0.4 units (except as noted)

Strength of selection within demes (σ) = 2 units

Population size = 100 individuals/deme

Number of generations = 20,000

Parameters explored

Cost of plasticity

Evolution of dispersal rate: no or yes

Linkage: none or complete

Initial dispersal rate

Initial mean reaction norm

Life-history pattern: selection before dispersal versus dispersal before selection