Figure 2. Phylogenetic tree based on the entire small sequences from 33 Rift Valley fever virus strains described by Bird et al. (16), from 6 sequences representative of the Kenya 1, 1a, and 2 lineages described by Bird et al. (18), and from 1 Madagascar strain circulating in 1991 and 12 Madagascar strains circulating in 2008. Boostrap percentages (from 1,000 resamplings) are indicated at each node. ◆ indicates sequences from the 2006–2007 Kenya-1 lineage, ● indicates sequences from the 2006–2007 Kenya-1a lineage, ▲ indicates sequences from the 2006–2007 Kenya 2 lineage, and ◇ indicates the 2008 Madagascar sequences. Scale bar indicates nucleotide substitutions per site.