Mutualism (biology)

Mutualism mutualistic symbiosis or referred to in the ecology of a correlation between creatures of two kinds, as opposed to competition or predator-prey relationship, both partners benefit from. In the U.S. literature, the word is used synonymously mutualism symbiosis with the German name in the narrow sense, while the word symbiosis - unlike the German designation symbiosis - is used for any coexistence of organisms of different species. Some authors differentiate between a symbiotic mutualism, in which both partners to live together permanently in space, and a nichtsymbiontischen mutualism, ( eg in the Zoogamie or Zoochorie ), in which the symbiotic partners meet only sporadically.

For a description and analysis of mutualistic ecological relationships organized various mathematical models are used in biology. Such models differ from one another according to whether they describe the temporal dynamics of mutualistic interacting populations in a rather short ( ecological ) or more long ( evolutionary ) time. A particularly simple and popular because of its wide applicability of the model can be written for two types of mutualisms in the form of ordinary differential equations: Known N1 and N2 are the population densities of the species retained in a mutualistic relationship, r1 and r2 intrinsic growth constants K1 and K2 capacity and b12 or b21 positive interaction coefficients, which indicate the strength of the mutualistic relationship, we obtain:

This type of model is a direct generalization of the logistic differential equation to the situation of two interacting populations. In these or similar form mutualisms in many textbooks of theoretical biology ( see literature) specified.


  • Skin flora / gut flora
  • Mycorrhizal
  • Ant and aphid
  • Clown fish and sea anemone
  • Cleaning symbioses such as when Oxpecker, the parasites of large animals like rhinos absammelt.
  • Oak / Jay (food for the bird; further spread of the seeds on a larger area and not just under the tree )