When well developed ecotonal communities may contain organisms characteristic of the overlapping communities plus species living only in the ecotone region, this condition is known as edge effect.
The yearly or seasonal phenomenon of cyclic fluctuation in population density causing periodic squeezing of some of the genes in a gene pool in random fashion is called bottleneck phenomenon. Pasteur effect is reduction in the amount of breakdown of respiratory substrate and evolution of carbon dioxide when an anaerobically respiring material is brought in oxygen containing environment.