In: Biology
Given the DNA sequence matrix below:
Fern AGCCCAGGCTTCGAATGTCC
Pine AGCTTCAGTGTCGCACTTCC
Oak AGCTTCAGCGTCACACATCC
Moss AACCTTGGTGTCAAACGTCC
1. Assuming that Moss is the outgroup, draw all three possible
trees of evolutionary
relationships among these species. Label your trees A, B, and
C.
2. Sum up the number of differences between the DNA sequences for
all pairs of species
(There are 6 total pairs of species to be compared). Based on these
values, which tree (A,
B, or C) do you think is best under the Genetic Distance
criterion?
3. Determine the minimum number of mutations required under the
parsimony criterion for
each of the three trees. Which is the most parsimonious tree?
Answer 1 & 2:)
Fern AGCCCAGGCTTCGAATGTCC
Pine AGCT TCAGTGTCGCACTTCC
Oak AGCT TCAGCGTCACACATCC
Moss AACCTTGGTGTCAAACGTCC
A G C C C A G G C T T C G A A T G T C C
A G C T T C A G T G T C G
C A C T T C C =
9
A G C T T C A G C G T C
A C A C
A T C C = 9
A A C C T T G G T
G T C A A A C G T C C =
8
Therefore following 6 pairs have been compared:
G C C C A G C T G A T G
G C T T C A T G G
C C T
G C T T C A C G
A C C
A
A C C T T G T G
A A C
G
Moss is an outer group:
If we compare Moss to Oak and Pine, we found that there are a total of 7 mutations
If we compare Moss to Fern, we found that there are a total of 8 mutations.
Therefore, we take the Fern nucleotide sequence as the comparable sequence because it has the most diverse sequence with the outer group.
Answer 3:)
The best tree on the basis of parsimony score is the First tree with the highest score 30.