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Proc Biol Sci. 2001 October 7; 268(1480): 2039–2045.
PMCID: PMC1088846

Complexity and fragility in ecological networks.


A detailed analysis of three species-rich ecosystem food webs has shown that they display skewed distributions of connections. Such graphs of interaction are, in fact, shared by a number of biological and technological networks, which have been shown to display a very high homeostasis against random removals of nodes. Here, we analyse the responses of these ecological graphs to both random and selective perturbations (directed against the most-connected species). Our results suggest that ecological networks are very robust against random removals but can be extremely fragile when selective attacks are used. These observations have important consequences for biodiversity dynamics and conservation issues, current estimations of extinction rates and the relevance and definition of keystone species.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.
  • McCann K, Hastings A. Re-evaluating the omnivory–stability relationship in food webs. Proc Biol Sci. 1997 Aug 22;264(1385):1249–1254. [PMC free article]

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