Table 2. Relations among sperm ATP amount, sperm length, sperm straight-line velocity and mass-specific metabolic rate eutherian in mammals.
| Dependent variable | Independent variable | Slope | R 2 | p-value | t-value | λ value | Effect size | CL(-) | CL(+) | n |
|---|---|---|---|---|---|---|---|---|---|---|
| ATP amount per sperm | Mass-specific metabolic rate | 0.4851 | 0.54 | 0.0002 | 4.5606 | <0.001ns,* | 0.7322 | 0.4580 | 1.4088 | 20 |
| ATP amount per sperm | Total sperm length | 1.4562 | 0.74 | <0.0001 | 7.6450 | <0.001ns,* | 0.8632 | 0.8560 | 1.7553 | 22 |
| Length-adjusted ATP concentration | Mass-specific metabolic rate | 0.2255 | 0.39 | 0.0032 | 3.4049 | <0.001ns,* | 0.6259 | 0.2593 | 1.2100 | 20 |
| Sperm straight-line velocity | ATP amount per sperm | 0.4113 | 0.50 | 0.0002 | 4.4722 | <0.001ns,* | 0.7071 | 0.4317 | 1.3310 | 22 |
| Sperm straight-line velocity | Length-adjusted ATP concentration | 0.7215 | 0.50 | 0.0002 | 4.5151 | <0.001ns,* | 0.7105 | 0.4385 | 1.3378 | 22 |
Phylogenetically controlled multiple regression analyses (PGLS). Superscripts following the λ value indicate significance levels (n.s. p>0.05; *p<0.05) in likelihood ratio tests against models with λ = 0 (first position) and λ = 1 (second position). Effect size r calculated from the t values and the non-central 95% confidence limits (CLs) for the z-transformed value of r are presented. Confidence intervals excluding 0 indicate statistically significant relationships. P-values and CL that indicate statistical significance are shown in bold. All variables were log10-transformed. n: number of species.