Species Number and Endemism: The Galápagos Archipelago Revisited

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Science  02 Mar 1973:
Vol. 179, Issue 4076, pp. 893-895
DOI: 10.1126/science.179.4076.893


Regression analyses to determine plant species number are repeated for the Galápagos Islands with new data. The multiple curvilinear regression gives the best prediction of species number, with island area making the only significant contribution. The proportion of species endemic to the Galápagos is highest in the arid, transition zone and on small islands, and lowest in the littoral and mesic zones. This is explained in terms of zone-specific immigration and extinction rates and the very recent appearance of moist upland climates in the archipelago.