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Herpetogeography of Puerto Rico. IV. Paleogeography, Faunal Similarity and Endemism
Harold Heatwole and Faustino MacKenzie
Vol. 21, No. 3 (Sep., 1967), pp. 429-438
Published by: Society for the Study of Evolution
Stable URL: http://www.jstor.org/stable/2406605
Page Count: 10
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A paleogeographic map of the Puerto Rican island shelf indicates that some of the small islands in this area became isolated from each other before the Pleistocene, others were separated 8,000 to 10,000 years B.P., and still others maintained their connections until 6,000 to 8,000 years B.P. Islands which have been separated a long time have lower faunal similarities with each other and have a higher degree of endemism (unless interisland distances are extremely short) than do those which have been more recently connected. There is an inverse relationship between faunal similarity and interisland distance. Puerto Rico has a high degree of endemism despite the presence of numerous nearby islands. This is probably due to its greater size and ecological diversity. Gene flow via animals transported by flotsam has probably been predominantly from east to west.
Evolution © 1967 Society for the Study of Evolution