Concluding remarks: historical perspective and the future of island biogeography theory

MacArthur and Wilson's equilibrium theory revolutionized the field of islan d biogeography and, to a large degree, ecology as well. The theory, which q uickly became the ruling paradigm of island biogeography, has changed littl e over the past three decades. It has not kept pace with relevant theory an d our growing appreciation for the complexity of nature, especially with em pirical findings that species diversity on many islands: 1) is not in equil ibrium; 2) is influenced by differences in speciation, colonization, and ex tinction among taxa; and 3) is influenced by differences among islands in c haracteristics other than area and isolation. The discipline of biogeograph y, itself, is in a state of disequilibrium. We may again be about to witnes s another paradigm shift, which will see the replacement of MacArthur and W ilson's theory. Wherever this shift may take us, we are confident that the next generation of biogeographers will still look to islands for insights i nto the forces that shape biological diversity.