Table 2. Phylogenetically-controlled multiple regression analyses of coefficient of variation (CV) of sperm dimensions in relation to body mass and testes mass.
Dependent variable | Predictor | Adjusted R 2 | Slope | F | P | Lambda (λ) | Effect size (r) | Effect size CLs |
CV HL | Body mass | 0.33 | 0.20 | 0.007 | 0.93 | 0.47*,* | 0.01 | (−0.39 to 0.42) |
Testes mass | −0.23 | 14.69 | <0.001 | 0.62 | (0.32 to 1.14) | |||
CV HW | Body mass | 0.06 | 0.13 | 0.02 | 0.88 | 0.79*,† | 0.03 | (−0.37 to 0.43) |
Testes mass | −0.14 | 3.69 | 0.06 | 0.37 | (−0.01 to 0.79) | |||
CV HA | Body mass | 0.20 | 0.24 | 0.72 | 0.40 | 0.38†,* | 0.17 | (−0.23 to 0.58) |
Testes mass | −0.20 | 7.77 | 0.01 | 0.50 | (0.14 to 0.96) | |||
CV MPL | Body mass | −0.07 | 0.06 | 0.003 | 0.95 | 0.68*,† | 0.01 | (−0.39 to 0.41) |
Testes mass | −0.06 | 0.27 | 0.60 | 0.10 | (−0.30 to 0.51) | |||
CV PPL | Body mass | 0.05 | 0.03 | 0.97 | 0.33 | 0.95*,† | 0.20 | (−0.20 to 0.61) |
Testes mass | −0.13 | 2.44 | 0.13 | 0.31 | (−0.08 to 0.72) | |||
CV TFL | Body mass | 0.37 | 0.17 | 2.42 | 0.13 | 0.17†,* | 0.30 | (−0.09 to 0.72) |
Testes mass | −0.31 | 14.82 | <0.001 | 0.62 | (0.32 to 1.14) | |||
CV TSL | Body mass | 0.36 | 0.19 | 1.86 | 0.18 | 0.16†,* | 0.27 | (−0.12 to 0.68) |
Testes mass | −0.31 | 14.53 | <0.001 | 0.62 | (0.31 to 1.13) |
Data have been processed as the logarithm of CV. All tests were conducted with 23 df. The superscripts following λ value indicate significance levels († n.s.; *P<0.05) in a likelihood ratio tests against models with λ = 0 (first position) and λ = 1 (second position). The effect size r was calculated from the F values; its noncentral 95% confidence limits (CLs) are also given. Confidence intervals excluding 0 indicate statistically significant relationships. P values and CLs that indicate statistical significance are shown in bold. Abbreviations: HL, head length; HW, head width; HA, head area; MPL, midpiece length; PPL, principal piece length; TFL, total flagellum length; TSL, total sperm length.