Figure 2.

Genetic and morphological distance measures. A) Neighbour-joining tree showing the genetic relationships between populations of nine-spined sticklebacks based on Nei's genetic distance (D_A) across all nine microsatellite loci. Percentage of bootstrap support > 50% for 10,000 replicates are shown. B) Cluster analysis based on population means of morphological characters. Mean standard length of fish (fish diagram) and a representative spine length estimate (mean pelvic spine length, upside down triangle) are presented and scaled proportionately for reference. Site abbreviations and groups are defined in Table 1. *The BN population lack pelvic spines.