Suppose that one obtained the following DNA sequence data for the four fly families and a non- fly insect (the outgroup) from a gene that is not related to morphology. We will call the DNA sequence positions 1 through 10, for reference (in fly family A, position 1 is a T, while position 10 is an A). Which of the characters (nucleotide positions) are variable among the fly families (not counting the outgroup? Which of the characters (nucleotide positions) are phylogenetically informative for cladistics? (Phylogenetically informative traits are those for which there is variation in the group of interest, and for which there is evidence of synapomorphies.) Solution Purines are 2 ringed structure= A,G whereas, pyramidines aresingle ringed structure = C,T Generally A = T (A double bonds with T) and G=C (G triple H bonds with C). Mutation causes a change in theDNA sequence. Two types 1. Transversions: Purine instead of a pyramidine or vice versa (Less frequent so more important for cladistics) A/G to C/T or vice versa. 2 ringed structure to 1 ringed structure See this is seen in all fly families at 7th(ABCD:AGGC) , 8th (ABCD:CTAC) and 9th (ABCD:GCTG)positions 2. Transitions: Purine instead of a puirne and pyramidine instead of a pyramidine (Easy and frequent) The Nucleotide positions are Bolded in the table are variable among the fly families. Among all Fly family C is most variable. (Take A, B, C, D and leave Out group). Phylogenetically informative traits are those for which there is variation in the group of interest and for which there is evidence of synapomorphies. All this is to know the members of a group which share a common history and to know their closely related species. Synapomorphy means any characteristic which is present in an ancestral species and that is shared exclusively (either in more or less modified form) by its evolutionary descendants. Mostly there is a much variation in the 7th, 8th and 9th position of the nucleotide in all fly families sequence so this will be more phylogenetically informative for cladistics and the 5th sequence is the most stable one. From the sequence fly family C is much more related to the out group sequence than all familiesFLY FAMILYDNA Sequence alignedpositions order12345678910ATGCGTTACGABTGCATTGTCACTCCGTAGATTDGCAGTTCCGAOU T GROUPGCAGTTGATT.

1. Suppose that one obtained the following DNA sequence data for the four fly families and a non-
fly insect (the outgroup) from a gene that is not related to morphology. We will call the DNA
sequence positions 1 through 10, for reference (in fly family A, position 1 is a T, while position
10 is an A). Which of the characters (nucleotide positions) are variable among the fly families
(not counting the outgroup? Which of the characters (nucleotide positions) are phylogenetically
informative for cladistics? (Phylogenetically informative traits are those for which there is
variation in the group of interest, and for which there is evidence of synapomorphies.)
Solution
Purines are 2 ringed structure= A,G whereas, pyramidines aresingle ringed structure = C,T
Generally A = T (A double bonds with T) and G=C (G triple H bonds with C).
Mutation causes a change in theDNA sequence. Two types
1. Transversions: Purine instead of a pyramidine or vice versa (Less frequent so more important
for cladistics) A/G to C/T or vice versa. 2 ringed structure to 1 ringed structure
See this is seen in all fly families at 7th(ABCD:AGGC) , 8th (ABCD:CTAC) and 9th
(ABCD:GCTG)positions
2. Transitions: Purine instead of a puirne and pyramidine instead of a pyramidine (Easy and
frequent)
The Nucleotide positions are Bolded in the table are variable among the fly families. Among all
Fly family C is most variable. (Take A, B, C, D and leave Out group).
Phylogenetically informative traits are those for which there is variation in the group of interest
and for which there is evidence of synapomorphies. All this is to know the members of a group
which share a common history and to know their closely related species. Synapomorphy means
any characteristic which is present in an ancestral species and that is shared exclusively (either in
more or less modified form) by its evolutionary descendants.
Mostly there is a much variation in the 7th, 8th and 9th position of the nucleotide in all fly
families sequence so this will be more phylogenetically informative for cladistics and the 5th
sequence is the most stable one. From the sequence fly family C is much more related to the out
group sequence than all familiesFLY FAMILYDNA Sequence alignedpositions
order12345678910ATGCGTTACGABTGCATTGTCACTCCGTAGATTDGCAGTTCCGAOU
T GROUPGCAGTTGATT