Islands

Abstract

Islands are simplified ecosystems that provide natural scientists with multiple, discrete units to study and upon which to base more general biogeographical, ecological and evolutionary theory. Island biogeographical theory has provided a framework for estimating species losses and to guide conservation management as continental landscapes become increasingly fragmented into ‘habitat islands’.

Keywords: adaptive radiation; biogeography; ecological assembly; equilibrium theory; taxon cycle

Figure 1.

The role of spatial and temporal scale in defining ecological and evolutionary processes. (1) Range and lifetime of an individual; (2) population scale operating in ecological time (e.g. competition); (3) population scale operating over evolutionary time (e.g. differentiation); (4) species scale (e.g. adaptive radiation). (Redrawn from Haila, ).

Figure 2.

Conceptual model depicting the relationship between geographical variables and evolutionary process (from Whittaker, ). The model indicates a trend from micro‐ to macro‐evolutionary changes as island isolation and area increase: large, distant islands are most disharmonic and possess most vacant niche space, perfect platforms for spectacular radiations; tiny islands, even if isolated, fail to provide for the persistence of large populations and complex ecosystems, and thus feature impoverished biotas of widespread species; large near‐mainland islands typically contain a full balance of species and lack the long‐term isolation that favours lineage radiation. For terms, see text, apart from ‘anagenesis’, which refers to speciation with little or no radiation, most prevalent on single, isolated islands in contrast to the radiations more prevalent on archipelagos.

Figure 3.

The equilibrium theory of island biogeography (ETIB) proposed by MacArthur and Wilson showing the relationship of distance from an island and source area on immigration (I), island area on extinction (E), and the intersection of both at an equilibrial point to produce a turnover rate (T) at a predictable species number (S). The roughly triangular area bounded by the darkened lines to the left of the turnover intersection point delimits the turnover rates and species numbers theoretically possible before equilibrium is reached (fl, far large; ns, near small).

close

References

Connor EF and Simberloff D (1979) The assembly of species communities: chance or competition? Ecology 60: 1132–1140.

Diamond JM (1975a) Assembly of species communities. In: Cody ML and Diamond JM (eds) Ecology and Evolution of Communities, pp. 342–444. Cambridge, MA: Harvard University Press.

Diamond JM (1975b) The island dilemma: lessons of modern biogeographic studies for the design of nature reserves. Biological Conservation 7: 129–146.

Diamond JM and May RM (1981) Island biogeography and the design of nature reserves. In: May RM (ed.) Theoretical Ecology, 2nd ed. pp. 228–252. Oxford: Blackwell

Feidler PL and Jain SK (eds) (1992) Conservation Biology: The Theory and Practice of Nature Conservation, Preservation and Management. London: Chapman and Hall.

Grant P (1986) Ecology and Evolution of Darwin's Finches. Princeton, NJ: Princeton University Press.

Groombridge B (ed) (1992) Global Biodiversity: Status of the Earth's Living Resources. London: Chapman and Hall.

Haila Y (1990) Towards an ecological definition of an island: a northwest European perspective. Journal of Biogeography 17: 561–568.

Lomolino MV and Weiser MD (2001) Towards a more general species–area relationship: diversity on all islands, great and small. Journal of Biogeography 28: 431–445.

Lovejoy TE, Beirregaard RO, Rylands AB et al. (1986) Edge and other effects of isolation on Amazon forest fragments. In: Soulé M (ed.) Conservation Biology: The Science of Scarcity and Diversity, pp 257–285. Sunderland, MA: Sinauer.

MacArthur RH and Wilson EO (1967) The Theory of Island Biogeography. Princeton, NJ: Princeton University Press.

Michaux JR, de Bellocq JG, Sará M and Morand S (2002) Body size increase in insular rodent populations; a role for predators? Global Ecology and Biogeography 11: 427–436.

Patterson BD and Atmar W (1986) Nested subsets and the structure of insular mammalian faunas and archipelagos. Biological Journal of the Linnean Society 28: 65–82.

Preston FW (1962) The canonical distribution of commonness and rarity, part 1. Ecology 43: 185–215.

Ricklefs RE and Bermingham E (2002) The concept of the taxon cycle in biogeography. Global Ecology and Biogeography 11: 353–361.

Rosenzweig ML (1995) Species Diversity in Space and Time. Cambridge: Cambridge University Press.

Schoener TW (1983) Rate of species turnover decreases from lower to higher organisms: a review of the data. Oikos 41: 372–377.

Simberloff DH and Abele LG (1976) Island biogeographic theory and conservation practice. Science 191: 285–286.

Steadman DW (1997) Human caused extinction of birds. In: Reaka‐Kudla ML, Wilson WE and Wilson WO (eds) Biodiversity II: Understanding and Protecting our Biological Resources, pp. 139–161. Washington DC: Joseph Henry Press

Terborgh J (1974) Preservation of natural diversity: the problem of extinction‐prone species. Bioscience 24: 715–722.

Whittaker RJ (1998) Island Biogeography: Ecology, Evolution, and Conservation. Oxford: Oxford University Press.

Whittaker RJ (2000) Scale, succession and complexity in island biogeography: are we asking the right questions? Global Ecology and Biogeography 9: 75–85.

Wilson EO (1961) The nature of the taxon cycle in the Melanesian ant fauna. American Naturalist 95: 169–193.

Wilson EO (1992) The Diversity of Life. London: Norton.

Further Reading

Brown JH and Lomolino MV (1998) Biogeography, 2nd edn. Sunderland, MA: Sinauer.

Darwin C (1845) Voyage of the Beagle. London: Murray.

Global Ecology and Biogeography (2000) 9(1) 1–92. [Island Biogeography Special Issue.]

Grant PR (ed.) (1998) Evolution on Islands. Oxford: Oxford University Press.

Grant PR and Weiner J (1999) Ecology and Evolution of Darwin's Finches. Princeton, NJ: Princeton University Press.

Hubbell SP (2001) The Unified Neutral Theory of Biodiversity and Biogeography. Princeton, NJ: Princeton University Press.

Quamman D (1996) Song of the Dodo; Island Biogeography in an Age of Extinctions. London: Hutchinson.

Weiher E and Keddy P (eds) (1999) Ecological Assembly Rules: Perspectives, Advances, Retreats. Cambridge: Cambridge University Press.

Williamson M (1992) Island Populations. Oxford: Oxford University Press.

Contact Editor close
Submit a note to the editor about this article by filling in the form below.

* Required Field

How to Cite close
Henderson, Scott J, and Whittaker, Robert J(Mar 2003) Islands. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1038/npg.els.0003234]