A. Genetic change in the population is also involved in this model of population regulation. Strong competitors are favored at high population levels, but at low population densities the selective forces favor members which have great reproductive potential. B. Microtines are often fugitive species which occupy temporary habitats. They depend on dispersal to occupy newly formed temporary habitats before their current habitat is replaced by the climax vegetation of the region. The organism's niche, or the trophic level occupied by the species.
Herbivores are common, but big, fierce animals are rare.
Click here to return to the Biology 251 home page.