Table 2. Population genetic structure inferred by analysis of variance (AMOVA).

The calculations take into account the division of all populations into two (possible effect of river) and nine (results of Bayesian clustering) groups.

Source of variation	d.f.	Sum of squares	Percentage of variation	F statistics
no groups
Among population within groups	15	736.36	54.5
Within population	112	517.17	45.5	Fst = 0.55
Total	127	1,272.09	100.0
2 clusters (opposite river banks)
Among groups	1	52.45	0.5	Fct = 0.005
Among population within groups	14	683.9	54.1	Fsc = 0.54
Within populations	110	517.2	45.4	Fst = 0.55
Total	127	12,532.2	100.0
9 clusters
Among groups	8	467.26	13.6	Fct = 0.14
Among population within groups	7	269.10	41.4	Fsc = 0.47
Within populations	110	517.17	45.0	Fst = 0.55
Total	125	1,253.52	100.0