Literaturdatenbank
Literaturdatenbank |
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Fritts, T. H. (1984). Evolutionary divergence of giant tortoises in galápagos. Biological Journal of the Linnean Society, 21.
Added by: Admin (28 Dec 2009 19:57:00 UTC) |
| Resource type: Journal Article BibTeX citation key: Fritts1984 View all bibliographic details  |
Categories: General Keywords: Chelonoidis, Chelonoidis nigra, Schildkröten = turtles + tortoises, Systematik = taxonomy, Testudinidae Creators: Fritts Collection: Biological Journal of the Linnean Society |
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| Abstract |
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Testudinidae Geochelone nigra The giant tortoises in the Galapagos Archipelago diverge considerably in size, and in shape and other carapace characteristics. The saddleback morphotype is known only from insular faunas lacking large terrestrial predators (i.e. Galapagos and Mauritius) and in Galapagos is associated with xeric habitats where vertical feeding range and vertical reach in agonistic encounters are adaptive. The large domed morphotype is associated with relatively cool, mesic habitats where intraspecific competition for food and other resources may be less intense than in xeric habitats. Other external characteristics that differ between tortoise populations are also correlated with ecological variation. Tortoises have radiated into a mosaic of ecological conditions in the Galapagos but critical data are lacking on the role of genetic and environmental controls on phenotypic variation. Morphological divergence in tortoises is potentially a better indicator of present ecological conditions than of evolutionary relationships.
Added by: Admin |