Fig. 2From: The Gap Procedure: for the identification of phylogenetic clusters in HIV-1 sequence dataClustering Results for RAxML with T c =90, T d =0.6. The maximum likelihood phylogenetic tree (n=94) produced by RAxML for Simulation 1. High, (≥90) medium (50–90) and low (<50) bootstrap values are denoted by yellow, grey and white rectangles, respectively. Cluster indices are represented by coloured tip labels; singletons are denoted in blackBack to article page