Figure 1

F _st for Lactase between 2 HapMap populations. F _st between CEU and YRI populations for all Lactase SNPs on the HapMap database. The X-axis reports the position on chromosome 2 (the value on the lower right is the absolute offset from the beginning of the chromosome), the Y-axis the F _st value. The dots represent the F _st values for existing SNPs on the HapMap database. The red boxes represent exon positions. To construct this chart HapMap frequency data and the UCSC Known Genes database were consulted. Biopython and Genepop were used to compute the F _st statistic.