Table 2.

Ecological scenarios considered in Baker's Law and their variation with regard to dispersal patterns

Ecological scenario	Dispersal frequency	Among-habitat dispersal	Importance of dispersal in mating system evolution
Island/continent (or exotic invader)	Rare	Highly asymmetric	Little
Range limits	Regular	Asymmetric	Middle
Metapopulation dynamics (e.g. weeds)	Regular	Symmetric	High

As a consequence of heterogeneous among-habitat dispersal, the heterogeneity of pollination environment is expected to influence more or less the outcome of mating system evolution.