Figure 1From: Discovering human history from stomach bacteriaThe relationships between human populations, as calculated from H. pylori found in stomachs and from mitochondrial DNA data. (a) Relationships between modern subpopulations of H. pylori [5]. Each subpopulation is represented by a circle with a diameter proportional to the genetic diversity within it. The centres of the circles are joined by a phylogenetic tree showing the relationships between the four subpopulations. Bacteria in each subpopulation are found predominantly in people who originate from the regions shown. (b) A population-level phylogenetic tree of the H. pylori geographic subpopulations shown in (a). (c) A median-joining network of human populations derived from mitochondrial DNA [14]. Such a network shows alternative potential evolutionary relationships between clusters. Each circle represents a cluster of mitochondrial types with a diameter proportional to the frequency of that type within the subpopulations. All non-African populations are derived from one African lineage; the network of relationships within this lineage is magnified (top). (a,b) Adapted from [5]; (c) adapted from [14].Back to article page