FIG 2 .

Latitude correlates with the phylogenetic diversity of Streptomyces as measured by both Faith’s phylogenetic diversity (A) and the net relatedness index (B). The Pearson correlation coefficient is provided along with the linear regression line. Symbols indicate the presence (□) or absence (○) of glaciation during the late Pleistocene. Numbers rank sites by time available for colonization, as follows: 1, WI; 2, NC; 3, MS; 4, TX; 5, CA; 6, FL; 7, NY; 8, ME; 9, WA; 10, OR; 11, AK1; 12, AK2. The FL site was below sea level at the beginning of the late Pleistocene, and sites in southern Wisconsin bound the Driftless Area, which escaped glaciation and has remained above sea level since the late Paleozoic.