Supplemental Table 2. Power analysis of AMOVA results for M. menidia haplotypic data in 2005 and 2006 applying no established regions, biogeographic regions (Carolinian, Virginian, Acadian) determined from the literature (Briggs 1974), and phylogeographic regions (Florida to Cape Cod, Gulf of Maine, and Gulf of St. Lawrence). Analysis was structured by: i) all samples collected for all sample sites (n=34), ii) all samples at the 12 - 2005 sample sites and all samples collected in the 13 unique 2006 samples sites (n=25), iii) same sites as “ii)” with 10 randomly selected samples per sample site (n=25), iv) 10 sample sites evenly spaced along the Atlantic coast (approx. 300km between sites) with all samples collected for each site (n=10), and v) the same 10 sites as “iv)” with 10 randomly selected samples per sample site (n=10). Significant P-values (P < 0.05) in bold.

Among Regions / Among Sites w/in Regions / Within Sites
Sites / Samples / DF / Var / % Var / ΦCT / P-value / DF / Var / % Var / ΦSC / P-value / DF / Var / % Var / ΦST / P-value
No Structure Imposed
i. / 34 / All / 33 / 0.020 / 4.22 / 995 / 0.418 / 95.78 / 0.042 / <0.001
ii. / 25 / All / 24 / 0.016 / 3.64 / 679 / 0.433 / 96.36 / 0.036 / <0.001
iii. / 25 / 10 / 24 / 0.012 / 2.91 / 225 / 0.415 / 97.09 / 0.029 / 0.013
iv. / 10 / All / 9 / 0.022 / 4.68 / 267 / 0.44 / 95.32 / 0.047 / <0.001
v. / 10 / 10 / 9 / 0.01 / 2.41 / 90 / 0.413 / 97.59 / 0.413 / 0.104
Biogeographic Regions
i. / 34 / All / 2 / 0.001 / 2.17 / 0.022 / <0.001 / 31 / 0.002 / 2.72 / 0.028 / <0.001 / 995 / 0.418 / 95.12 / 0.049 / <0.001
ii. / 25 / All / 2 / 0.008 / 1.77 / 0.018 / <0.001 / 22 / 0.011 / 2.4 / 0.023 / <0.001 / 679 / 0.431 / 95.83 / 0.042 / <0.001
iii. / 25 / 10 / 2 / 0.009 / 2.13 / 0.021 / 0.003 / 22 / 0.006 / 1.41 / 0.014 / 0.141 / 225 / 0.415 / 96.46 / 0.035 / 0.012
iv. / 10 / All / 2 / 0.005 / 1.12 / 0.011 / 0.125 / 7 / 0.018 / 3.85 / 0.038 / <0.001 / 267 / 0.44 / 95.03 / 0.050 / <0.001
v. / 10 / 10 / 2 / 0.002 / 0.52 / 0.005 / 0.334 / 7 / 0.009 / 2.04 / 0.021 / 0.156 / 90 / 0.413 / 97.44 / 0.026 / 0.103
Phylogeographic Regions
i. / 34 / All / 2 / 0.030 / 6.38 / 0.064 / <0.001 / 31 / 0.004 / 0.83 / 0.009 / 0.028 / 995 / 0.418 / 92.78 / 0.072 / <0.001
ii. / 25 / All / 2 / 0.250 / 5.44 / 0.054 / <0.001 / 22 / 0.004 / 0.82 / 0.009 / 0.063 / 679 / 0.433 / 93.74 / 0.063 / <0.001
iii. / 25 / 10 / 2 / 0.021 / 4.88 / 0.048 / <0.001 / 22 / 0.002 / 0.42 / 0.004 / 0.492 / 225 / 0.415 / 94.69 / 0.053 / 0.009
iv. / 10 / All / 2 / 0.040 / 8.32 / 0.083 / 0.001 / 7 / -0.002 / -0.35 / -0.004 / 0.795 / 267 / 0.440 / 92.02 / 0.080 / <0.001
v. / 10 / 10 / 2 / 0.041 / 9.42 / 0.094 / 0.002 / 7 / -0.015 / -3.33 / -0.037 / 1.000 / 90 / 0.413 / 93.91 / 0.061 / 0.099

DF = Degrees of freedom; Var = Variation component; % Var = % Variation; 10 populations for analysis “iv)” and “v)” (correspond to population numbers in Table 1): 1, 3, 5, 8, 12, 15, 18, 21, 23, 25.

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