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46 Cards in this Set
- Front
- Back
Evolution as a growing tree |
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Problems with the first evolutionary tree |
Focused off the theory that organisms evolve to form more complicated forms (Hitchcock 1840). Other trees were based off of similarities (Haeckel 1866) |
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Taxonomy + Phylogenetics = Systematics |
*Systematics is the common way it's done |
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Phylogenies |
Phylogeny is the true evolutionary history of a group of organisms. A phylogenetic tree is a visual hypothesis of evolutionary relationships based on one or more genetically determined traits (morphology, physiology, development or molecules (DNA/aa). |
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Of the 4 traits, which is the most commonly used class of data for building trees? |
Molecules (DNA or amino acid sequences) because every living thing has DNA |
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Phylogeny Tree diagram |
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B. Common Ancestor |
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Lineages: From Populations to Species |
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Anatomy of a phylogeny: Nodes, Branches, Root, Lineage, Tip |
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Phylogenetic trees can be drawn any ways, but what must always be shown? |
•No matter what, they shouldrepresent a branching pattern that reflects common descent and splitting oflineages through time |
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Rooting phylogenetic trees |
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Unrooted taxon tree with different rootings |
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As taxa are added to a study,the number of possible phylogenetic trees grows exponentially |
Each phylogenetic tree is a hypothesis that can be tested using the organisms’ characteristics |
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Trees can be drawn with fewer taxa... |
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Branches can be rotated around nodes without changing the topologyof the tree |
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Systematics: Clade |
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Systematics: Paraphyletic Group |
Clade does not = Paraphyletic Group |
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Systematics: Polyphyletic Group |
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Why are reptiles a polyphyletic group? |
Reptiles are a paraphyletic group because the name does not include their avian descendants. To be monopyletic, must include birds in clade. |
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Why are flying vertebrates a polyphyletic group? |
Flying vertebrates (bats &birds) are a polyphyletic group becauseyou can’t include theircommonancestor without includingmany othertaxa |
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B. 5 |
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Taxonomic Revision |
Fish are not a monophyletic group unless you include all other vertebrates |
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Ancestral vs Derived: Synapomorphy and Outgroup |
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Internal Egg: Ancestral vs Derived |
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Are monotremes primitive? |
No they aren't |
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Why aren't monotremes primitive? |
Not primitive because still alive |
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How can we use synapomorphies to build phylogenetic trees? |
Build a data matrix using severalmorphologicalcharacters |
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Character Matric |
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Maxium Parsimony |
*Least steps doesn't always mean correct tree |
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What would a tree look like if we had 3 equally parsimonious trees? |
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Branch length and cladogram |
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Branch Length & Phylogram |
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Branch Length & Chronogram |
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Using Gobies to test evolutionary hypothesis... |
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Consistent with convergent evolution. This is a phylogram cuz tips aren't same length and because it's a scale bar. |
Convergence has led to smaller eyes and elongated bodies when organisms live in dark regions where eyes aren't required |
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It's an old structure, but new function |
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