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Unformatted text preview: A note on reading cladograms.
When reading cladograms you are interested in the pattern of splitting or the branch order. When a branch splits you get two sister taxa. These can be shown with one on the right and the other on the left, or vice versa. So, the two trees below are equivalent. Picture the drawing as pipe fitting where each joint point, called a node, is able to spin. Mammals Reptiles Reptiles Mammals In the diagram below the mammal group is the sister taxon to the reptiles, but reptiles has been broken up into lizards and snakes, plus birds, crocs, and turtles. Vertebrate tree: similar forelimbs Liz a sna rds & kes Tur tl Cro Lun gfis hes Aquatic only modification of jointed fins to become limbs s Ray fish finned es cod ilia ns hib ians Bir ds Am p C oe laca nth Ma mm es als In the diagram below, mammals have been divided into four branches, but reptiles would diverge from the tree below the last branch. To compare trees, remember to compare the branching and sister taxa shown. ...
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- Fall '08
- Cladistics, taxon, sister taxa