Competition is also present between species ("interspecific"). When resources are limited, several species may depend on these resources. Thus, each of the species competes with the others to gain access to the resources. As a result, species less suited to compete for the resources may die out unless they adapt by character dislocation, for instance. According to evolutionary theory, this competition within and between species for resources plays a significant role in natural selection. At shorter time scales, competition is also one of the most important factors controlling diversity in ecological communities, but at larger scales expansion and contraction of ecological space is a much more larger factor than competition. This is illustrated by living plant communities where asymmetric competition and competitive dominance frequently occur. Multiple examples of symmetric and asymmetric competition also exist for animals.