evolgen

Phylogeny Friday – 19 May 2006

As I mentioned previously, I’m busy preparing some data for a meeting next week. I don’t have much time to devote to Phylogeny Friday, so I’ll be sharing some of my own data with you. This data is nothing special; it just happens to be the data I finished analyzing a few minutes ago. It’s open, I could build a tree, and I’ll show you that tree below the fold.

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This tree contains a scant three sequences. The two closely related sequences both come from Drosophila pseudoobscura and the outgroup is a gene from D. melanogaster. This gene was duplicated along the D. pseudoobscura lineage. In the time since the duplication event, the two copies in the D. pseudoobscura lineage have diverged from each other. One copy has accumulated two amino acid substitutions, and the other copy has accumulated one amino acid substitution. Remember how we discussed how relative rates of evolution can be used to detect changes in selective constraint? Well, these paralogs diverged too recently for us to have enough power to detect any differences in rates along the two lineages.

I know it’s not a very interesting tree, but it’s all I have time for today. Sorry. This next week will be hectic, so don’t expect much from Phylogeny Friday for another couple of weeks.