Fig. 2 in Geographical versus ecological isolation of closely related black flies (Diptera: Simuliidae) inferred from phylogeny, geography, and ecology

Fig. 2 Principal components analysis (PCA) of stream variables for four species in Clade I-1 of subgenus Gomphostilbia in Thailand. Factor score 1 (PC-1) explained 33.75 % of the total variation and was related positively to stream width, depth, velocity, pH, and conductivity and negatively to altitude. Factor score 2 (PC-2) explained 26.76 % of the total variation and was positively related to stream width, depth, and velocity and negatively to pH and conductivity. The four taxa of Clade I-1 were separated in environmental space along the two axes