Table 5.

Genetic distances and substitution rates of protein-coding genes of Bathymodiolus symbiotic bacteria between the two geographical groups, EPR + GAR and PAR

Gene	All codon positions	3rd pos.	1st and 2nd pos.	Synonymous distance (±SE) (syn. Substitution rate)	Nonsynonymous distance (±SE) (nonsyn. Substitution rate)
COI	0.0226a	0.0676	0.0001	0.102 (±1.37 × 10–6) (0.96 b − 2.041c %)	7.31 × 10–5 (±6.47 × 10–8) (6.89 × 10–4–1.46 × 10–3%)
dnaK	0.0274	0.0751	0.0036	0.116 (±1.11 × 10–6) (1.10–2.33%)	2.94 × 10–4 (±1.18 × 10–7) (2.75 × 10–3–5.48 × 10–3%)
pgi	0.0261	0.0705	0.0038	0.105 (±1.62 × 10–6) (0.99–2.10%)	3.24 × 10–3 (±9.96 × 10–8) (3.06 × 10–2–6.48 × 10–2%)
pykF	0.0147	0.0.043	0.0005	0.046 (±2.03 × 10–6) (0.43–0.92%)	2.20 × 10–3 (±1.85 × 10–7) (2.08 × 10–2–4.40 × 10–2%)
rpoD	0.0149	0.0448	0.0000	0.067 (±9.65 × 10–7) (0.63–1.33%)	6.33 × 10–5 (±5.10 × 10–8) (5.98 × 10–4– 1.27 × 10–3%)
soxA	0.0124	0.0356	0.0008	0.051 (±3.43 × 10–7) (0.48–1.01%)	1.02 × 10–3 (±1.40 × 10–7) (9.65 × 10–3–2.04 × 10–2%)
Average	0.0197	0.0232	0.0015	0.081 (±1.24 × 10–6) (0.77–1.62%)	1.15 × 10–3 (±1.10 × 10–7) (0.01–0.02%)

^aNucleotide difference per site

^bSubstitution rate (percentage per nucleotide per million years) calibrated by the geological time of the formation of Easter Microplate, estimated as about 5.3 million years ago

^cSubstitution rate calibrated by 2.5 million years as an age of the Easter Microplate