Table 5 Summary results from a general linear mixed model for threespine sticklebacks from 25 freshwater locations testing for associations along the trophic axis (i.e. head shape axis in PC2 in Fig. 5) with predictor factors gillraker length and number, mean depth of lake, proportion of organic carbon obtained from littoral sources (α), trophic position (Tpos), sex and length (cm)
Test | Source | DF | Estimate ± SE | F | P |
|---|---|---|---|---|---|
Trophic axis | Intercept | 0.004 ± 0.012 | 0.727 | ||
R2 = 0.41 | Gillraker length (mm) | 1 | −0.019 ± 0.004 | 18.44 | < 0.001 |
N fish = 481 | Gillraker number | 1 | −0.001 ± 0.000 | 6.43 | 0.012 |
N populations = 25 | Mean depth (m) | 1 | −0.001 ± 0.000 | 6.55 | 0.018 |
α | 1 | 0.000 ± 0.003 | 0.00 | 0.967 | |
Tpos | 1 | 0.001 ± 0.003 | 0.26 | 0.612 | |
Sex | 1 | 0.002 ± 0.001 | 10.65 | 0.001 | |
Total length (cm) | 1 | 0.007 ± 0.001 | 32.57 | < 0.001 |