HOMEWORK # 2
CONSTRUCTING PHYLOGENIES
Below are two sets of amino acid sequences from 6 different species numbered 1-6. Using what we have learned about constructing phylogenetic trees (refer to your notes and textbook) draw a phylogenetic tree (hypothesis about relationships) based on the similarities shared among the 6 species in each data set. Note: the 6 species are the same in each dataset and you should have one phylogenetic hypothesis (tree) for each set of sequences.
Protein Sequence Set A
Species 5
GNAGYGAEALERM
Species 6
GNAGYGAEALERM
Species 2
NHAAFGAEALERM
Species 3
NHSAYGAEALERM
Species 1
AHAGYGAEALERM
Species 4
GHAGYGGEALDRT
Protein Sequence Set B
Species 5
LCNSIGSLFQTFSI
Species 6
LCNSTGSLFQTFAI
Species 2
LCNSTGSLFQTFAI
Species 3
LCNSTGSLFQTFAI
Species 1
LCNSIGSLFQTFSI
Species 4
LCNSIGSLFQTFSI
Questions: If the two different sets of sequences result in different hypotheses, what might explain these differences (think about what we've been discussing in class)? What types of additional information would you need to decide among the different hypotheses? Which of the trees is the preferred tree and why?