Panel A. Rarefaction analysis of cutaneous microbiota in relation to sampling time in samples from arms (Brown), axilla (Black) and scalp (Yellow), African-American (AA, n = 108 samples); African-Continental (AC, n = 66); Caucasian-American (CA, n = 96); East-Asian (EA, n = 150); Latin-American (LA, n = 114); South-Asian (SA, n = 96). Rarefaction analysis represented by phylogenetic distance. The solid and dashed lines indicate samples collected before (T1) and after (T2) a special soap wash was used, respectively. Only a significant difference between time-points was found for the SA group. Panel B. Intra- and inter-group beta-diversity over time. Mean (±SD) pairwise unweighted UniFrac distances are shown. The ethnic groups are colored as described in Fig 1. Significance was determined by one-way ANOVA with the Tukey method for correction for multiple comparisons (*<0.05; **<0.01; ***<0.001; ****<0.0001).