Table 3. Analysis of Molecular Variance (AMOVA) results when populations are grouped by river basin.

Source of variation	d.f.	Sum of Squares	Variance Components	Percentage of Variation
Among groups	3	118.369	0.100	2.52
Among populations within groups	9	135.351	0.116	2.93
Among individuals within populations	584	2421.137	0.402	10.14
Within individuals	597	1995.500	3.343	84.41
Total	1193	4670.356	3.953

The amount of variation in each partition was significantly different from zero (P<0.05) via permutation test. Corresponding fixation indices are given in the text.