BIS 2C 29 Homoplasy is similarity due to convergent evolution BIS 2C 30 Bird

Bis 2c 29 homoplasy is similarity due to convergent

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BIS 2C 29
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Homoplasy is similarity due to convergent evolution. BIS 2C 30 Bird Bat Dragonfly Pterosaur
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Synapomorphies are shared, derived characteristics; they define monophyletic groups. BIS 2C 31 …just because some members within a lineage lose or modify synapomorphic characteristics, doesn’t mean they are no longer synapomorphies…
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T/F (A=True, B=False) Wings are a synapomorphy of birds. Clicker Question 32 flight homoplasy bird wings synapomorphy
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Homology and synapomorphy are often confused; at some level , all homologous characters are synapomorphies. BIS 2C 33 Mammals hair milk mammary glands four-chambered heart mammals plant help figure out relationships among mammals synapomorphy that definemammals as a monophyletic group
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BIS 2C 34 Mammals hair milk mammary glands four-chambered heart Homology and synapomorphy are often confused; at some level , all homologous characters are synapomorphies.
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BIS 2C 35 A. Nuts & Bolts B. Relationships C. Homology & Homoplasy D. Building Phylogenies E. Using Phylogenies
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Building phylogenies is a science in itself; combining knowledge from fields such a molecular biology, ecology, animal behavior, statistics, computer science. BIS 2C 36 The phylogenetic history of a group of organisms is inferred from their characters . We need to collect data from our taxa; morphology, genetics, and behavior are most commonly used. Trees are hypotheses that can be tested by adding more data, taxa, or using different analytical methods .
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Select taxa of interest (ingroup); include one or more outgroups . BIS 2C 37 Eastern spinebill (outgroup) Honeyeaters (ingroup) outgroup : taxon that is as closely related to the ingroup as possible without being part of it; based on prior knowledge.
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BIS 2C 38 C1 C2 C3 C4 C5 C6 C7 C8 C9 Taxon 1 0 0 1 A A G C A C Taxon 2 1 0 1 A A G C A C Taxon 3 1 1 0 A A G T A C Taxon 4 1 1 0 A A G T T C Assemble the data into a data matrix . Morphology and behavior are coded numerically; DNA sequence data is coded by nucleotides .
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BIS 2C 39 Select a method of inference; both have strengths and weaknesses. Statistical methods: phylogenies are estimates, and the best tree is the one which has the highest probability of being observed given a model (of molecular evolution). Parsimony: the best tree is the one with the fewest number of character changes. ** Computationally less intensive; lots of hidden assumptions. ** Computationally intensive ; requires an explicit model.
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BIS 2C 40 Building phylogenies is mathematically challenging ; we use unrooted trees to make the problem more manageable. A D C B Unrooted trees lack a root branch which gives them unusual properties relative to rooted phylogenies.
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T/F (A=True, B=False, C=Sometimes) Taxon A is sister to taxon B.
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