Researches on Population Ecology

, Volume 38, Issue 2, pp 211–218 | Cite as

Evolution of mutualistic symbiosis: A differential equation model

  • Norio Yamamura
Special Feature 2


In geological history, rapid speciation, called adaptive radiation, has occurred repeatedly. The origins of such newly developing taxa often evolved from the symbiosis of different species. Mutualistic symbioses are generally considered to evolve from parasitic relationships. As well as the previous model of host population with discrete generations, a differential equation model of host population with overlapping generations shows that vertical transmission, defined as the direct transfer of infection from a parent host to its progeny, is an important factor which can stimulate reduction of parasite virulence. Evolution of the vertical transmission rate from both points of view, the parasite and the host, is analyzed. There is a critical level of the rate, below which an evolutionary conflict arises (the parasite would want an increase in the rate while the host would not), and above which both species would correspond to increase the rate. Therefore, once the parasite dominates the evolutionary race so as to overcome this critical level, one-way evolution begins toward a highly mutualistic relationship with a high vertical transmission rate, possibly creating a new organism through symbiosis with perfect vertical transmission. Changes in other parameters may decrease the critical level, initiating one-way evolution. However, changes in traits, probably developed through a long interrelationship in parasitism, do not necessarily induce the evolution of mutualism. Establishment of the ability to make use of metabolic and digestive wastes from the partner certainly facilitates the evolution of mutualism, while improvements in reproductive efficiency of parasites and reduction of negative effects from exploitation in hosts on the contrary disturb mutualism.

Key words

mutualistic symbiosis vertical transmission differential equation conflict mutual use of wastes 


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  1. Bremermann, H. J. and J. Pickering (1983) A game-theoretic model of parasitic virulence.Journal of Theoretical Biology 100: 411–426.PubMedCrossRefGoogle Scholar
  2. Breznak, J. A. (1975) Symbiotic relationships between termites and their intestinal microbiota.Symposia of the Society for Experimental Biology 29: 559–580.PubMedGoogle Scholar
  3. Buchner, P. (1965)Endosymbiosis of animals with plant microorganisms. Wiley Interscience, New York.Google Scholar
  4. Ewald, P. W. (1987) Transmission modes and evolution of the parasite-mutualism continuum.Annals of the New York Academy of Sciences 503 (Endocytobiology III): 295–305.PubMedGoogle Scholar
  5. Ewald, P. W. (1994)Evolution of infectious disease. Oxford University Press, Oxford.Google Scholar
  6. Fenner, F. (1965) Myxoma virus andOryctolagus cuniculus. pp. 485–501.In H. G. Baker and A. L. Stebbins (eds.)The genetics of colonizing species. Academic Press, New York.Google Scholar
  7. Fleming, J. G. W. and M. D. Summers (1991) Polydnavirus DNA is integrated in the DNA of its parasitoid wasp host.Proceedings of National Academy of Sciences of the USA 88: 9770–9774.CrossRefGoogle Scholar
  8. Ishikawa, H. (1988)Symbiosis and evolution. Baihukan, Tokyo. (in Japanese)Google Scholar
  9. Jeon, K. W. (1972) Development of cellular dependence in infective organisms: microsurgical studies in amoebas.Science 176: 1122–1123.PubMedCrossRefGoogle Scholar
  10. Klein, R. W., D. Kovac, A. Schellerich and U. Maschwitz (1992) Mealybug-carrying by swarming queens of a southeast Asian bamboo-inhabiting ant.Naturwissenschaften 79: 422–423.CrossRefGoogle Scholar
  11. Margulis, L. (1993)Symbiosis in cell evolution. 2nd ed. Freeman, New York.Google Scholar
  12. May, R. and R. Anderson (1983) Epidemiology and genetics in the coevolution of parasites and hosts.Proceeding of Royal Society, London, Series B 219: 281–313.Google Scholar
  13. May, R. and M. Nowak (1995) Coinfection and the evolution of parasite virulence.Proceeding of Royal Society, London, Series B 261: 209–215.Google Scholar
  14. Maynard-Smith, J. (1974) The theory of games and the evolution of animal conflicts,Journal of Theoretical Biology 47: 209–221.CrossRefGoogle Scholar
  15. Maynard-Smith, J. (1982)Evolution and the theory of games. Cambridge University Press, Cambridge.Google Scholar
  16. Maynard Smith, J. (1989) Generating novelty by symbiosis.Nature 341: 284–285.CrossRefGoogle Scholar
  17. McFadden, G. and P. Gilson (1995) Something borrowed, something green: lateral transfer of chloroplasts by secondary endosymbiosis.Trends in Ecology and Evolution 10: 12–17.CrossRefGoogle Scholar
  18. Nowak, M. (1991) The evolution of viruses. Competition between horizontal and vertical transmission of mobile genes.Journal of Theoretical Biology 150: 339–347.PubMedCrossRefGoogle Scholar
  19. Price, P. W. (1991) The web of life: Development over 3.8 billion years of trophic relationships. pp. 262–272.In L. Margulis and R. Fester (eds.)Symbiosis as a source of evolutionary innovation. The MIT press, Cambridge.Google Scholar
  20. Roughgarden, J. (1975) Evolution of marine symbiosis—A simple cost-benefit model.Ecology 56: 1201–1208.CrossRefGoogle Scholar
  21. Sasaki, A. and Y. Iwasa (1991) Optimal growth schedule of pathogens within a host: switching between lytic and latent cycles.Theoretical Population Biology 39: 201–239.PubMedCrossRefGoogle Scholar
  22. Stolts, D. B. and S. B. Vinson (1979) Viruses and parasitism in insects.Advances in Virus Research 24: 125–171.CrossRefGoogle Scholar
  23. Yamamura, N. (1987) Evolutionary stable strategy (ESS) models of copulation and mate guarding. pp. 197–211.In Y. Ito, J. L. Brown and J. Kikkawa (eds.)Animal societies, theories and facts. Japan Scientific Societies Press, Tokyo.Google Scholar
  24. Yamamura, N. (1993) Vertical transmission and evolution of mutualism from parasitism.Theoretical Population Biology 44: 95–109.CrossRefGoogle Scholar
  25. Yamamura, N. (1996) Diversity and evolution of symbiotic interaction.In T. Abe, S. A. Levin and M. Higashi (eds.)Biodiversity: an ecological perspective. Springer, New York. (in press)Google Scholar
  26. Yamamura, N. and M. Higashi (1992) An evolutionary theory of conflict resolution between relatives: altruism, manipulation, compromise.Evolution 46: 1236–1239.CrossRefGoogle Scholar

Copyright information

© Society of Population Ecology 1996

Authors and Affiliations

  • Norio Yamamura
    • 1
  1. 1.Center for Ecological ResearchKyoto UniversityKyotoJapan

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