Phylogenetic tree based on Clustal X alignments of the reverse transcriptase domains of several Pao-like and non-Pao-like elements, drawn using the neighbor joining algorithm. The names of elements, followed by host species names, in parentheses, are provided. Size bar reflects phylogenetic divergence in genetic distance units. Bootstrap values were drawn from 1,000 trials.
Copeland et al. BMC Evolutionary Biology 2005 5:20 doi:10.1186/1471-2148-5-20