If the
plant is not self-pollinating (autogamous), then a generalist
pollination system (e.g., wind pollination) may confer a
selective advantage over a specialized pollination system
because the specialist pollinator may not be present in the
area being colonized (Baker 1965). Plants that colonize
disturbed areas are subject to further selective pressures.
These habitats tend to have high levels of light and,
consequently, low levels of soil moisture. Therefore, a
plant that is tolerant of high light levels would have a
selective advantage over a plant that is shade tolerant, and
a plant that is adapted to low soil moisture would have a
selective advantage over a plant that is adapted to more
moist habitats (Baker 1967).