I made this video (below the fold) to illustrate the steps involved in making a phylogenetic tree. The basic steps are to:
Build a data set
Align the sequences
Make a tree
In the class that I'm teaching, we're making these trees in order to compare sequences from our metagenomics experiment with the multiple copies of 16S ribosomal RNA (rRNA) genes that we can find in single bacterial genomes. Bacteria contain between 2 to 13 copies of 16S rRNA genes and we're interested in knowing how much they differ from each other. Later, we'll compare the 16S ribosomal RNA genes from multiple species…