Goals: A. Construct a simple parsimony tree using characters. B. Construct a simple uncorrected p-distance matrix tree. Two Types of Data for Constructing Trees There are two major different types of data that can be used to construct phylogenetic trees. One type of data is morphological character data. Using this approach, trees are constructed based on the similarities in morphology that organisms share with each other. For instance, conceptually you would group humans and chimps together because they share many morphological features, and then you would place gorillas outside of this group, because gorillas share fewer features than humans and chimps. Another major type of data is DNA sequence data. A. Morphological Character-Based Parsimony Trees Create a matrix of characters, listing characters possessed by each organism (where 0 = ab se n t and 1 = present for each character). We can then identify organisms with similar characters and build a tree using the data presented in the matrix. 5) We also have sister groups, which denote the closest relative of another group (or unit) in an evolutionary tree. Mammals are the sister group to what group? (2 pt.) 6) Look at the Character \#8 (warm blooded). Redraw your tree exactly as you drew it above, but add character #8 to the tree. Is there more than one possibility with how character #8 is mapped on the tree? What explanation do you have for this evolutionary pattern? Remember that constructing trees is an inference process, so there may be several explanations for the observed evolutionary pattern. (hint: think of loss and/or gain of characters mapped on the tree) (10 pts.)
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Goals- A- Construct a simple parsimony tree using characters- B- Const.docx
1. Goals: A. Construct a simple parsimony tree using characters. B. Construct a simple uncorrected
p-distance matrix tree. Two Types of Data for Constructing Trees There are two major different
types of data that can be used to construct phylogenetic trees. One type of data is morphological
character data. Using this approach, trees are constructed based on the similarities in morphology
that organisms share with each other. For instance, conceptually you would group humans and
chimps together because they share many morphological features, and then you would place
gorillas outside of this group, because gorillas share fewer features than humans and chimps.
Another major type of data is DNA sequence data. A. Morphological Character-Based
Parsimony Trees Create a matrix of characters, listing characters possessed by each organism
(where 0 = ab se n t and 1 = present for each character). We can then identify organisms with
similar characters and build a tree using the data presented in the matrix. 5) We also have sister
groups, which denote the closest relative of another group (or unit) in an evolutionary tree.
Mammals are the sister group to what group? (2 pt.) 6) Look at the Character #8 (warm
blooded). Redraw your tree exactly as you drew it above, but add character #8 to the tree. Is
there more than one possibility with how character #8 is mapped on the tree? What explanation
do you have for this evolutionary pattern? Remember that constructing trees is an inference
process, so there may be several explanations for the observed evolutionary pattern. (hint: think
of loss and/or gain of characters mapped on the tree) (10 pts.)
