BIOB51H3 Lecture Notes - Lecture 6: Feathered Dinosaur, Transitional Fossil, Zhenyuanlong
10 Mar 2020
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If traits evolved more than once, then it is not expected via evolution. In this case construct a consensus tree which is average of all trees. It"s not the same as any other tree: consensus trees may contain a polytomy which suggests we need to add more information. Fossils can be used to constrain (or reveal) divergence times. You can scale a phylogeny tree by using fossils. Phylogenies can be used to generate hypotheses about major transitions: coelacanth is a tetrapod fish thought to be extinct in africa. Phylogeny reveals how tetrapod traits evolved over time: and these traits can be traced from one group to the next. Homology can be obvious or not: orangutan vs. human feet (obvious similarity); reptile vs. human feet (less obvious similarity)
