TABLE 1.

Contributions of recombination and mutation to nucleotide diversity in subseafloor populations^a

Group	No. of strains	R/θ	δ	ν	r/m ratio	Avg no. of pseudogenes (SD)	Avg dN/dS ratio (SD)
All subseafloor and type strains	34	0.053	244	0.055	0.71	37 (±8)	0.025 (±0.011)
Type strains	13	0.04	333	0.053	0.71	21 (±3)	0.022 (±0.01)
Subseafloor strains	21	0.006	500	0.026	0.078	48 (±4)****	0.038 (±0.007)**

^aThe results from ClonalFrameML analysis were used to calculate the relative contributions of recombination and mutation in the core genome (r/m). R/θ, relative ratio of recombination compared to mutation; δ, average length of recombined (imported) DNA; ν, mean divergence of imported DNA. Also displayed are the average numbers of pseudogenes and dN/dS ratios (± standard deviations). **, P = 0.005 by a two-sided t test; ****, P = 0.000001 by a two-sided t test.