FIG. 7.
16S rDNA gene tree for Cariaco Basin samples. The boxes identify eubacteria sampled from different environments, as follows: open boxes, 1,310 m; solid boxes, 500 m; shaded boxes, 320 m. The tree was generated by using the methods described in the legend to Fig. 6. None of the groups exhibited a restricted distribution. The asterisk indicates the one sequence (phylotype) that accounted for significant differentiation between the shallow-water sample (320 m) and the two deeper-water samples based on the FST test when all sequences were analyzed. Scale bar = 0.05 substitution per site.