Timing of the most recent mutation as determined by inter-species whole genome alignments. Each base pair in which the human reference genome differs by substitution from one of its inferred ancestral genomes is colored in either grey (event prior to the primate branch), blue (primate specific), red (human specific, fixed variant), or yellow (human specific segregating variant, i.e. SNP). Clicking on a mutation position reveals the sub-tree of species which have inherited the same mutation from their common ancestor. It also reveals a score that represents the age of the mutation in arbitrary units, and determines the intensity of the coloring. The more recent the mutation, the lower the score and the darker the color.