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| | GEOL 102 Phylogeny, the Tree of Life |
 | | In the above example, Amphibia, Mammalia, Testudines, Lepidosauria, Crocodylia, and Aves are all terminal taxa; Tetrapoda, Amniota, Reptilia, Diapsida, and Archosauria are named nodes. |
 | | Two taxa which meet at a node are called sister taxa, and are each other's closest relatives (i.e., they represent the two lineages which diverged from that particular common ancestor). |
 | | The ingroup represents the assemblage of taxa of primary interest in any particular study; the outgroup is the sister taxon to the ingroup. |
| www.geol.umd.edu /~tholtz/G102/102phyl.htm (1281 words) |
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