Sample clustering. An UPGMA tree showing the clustering of the samples based on the UniFrac analysis. Weighted classification was used. The scale bar shows the distance between clusters in UniFrac units: a distance of 0 means that two environments are identical and a distance of 1 means that two environments contain mutually exclusive lineages. Shading was used to differentiate the three nodes representing different stages of the process.
Partanen et al. BMC Microbiology 2010 10:94 doi:10.1186/1471-2180-10-94