Table 1.
Correlations between latitude, and variables relating to species richness and diversification. (Data are means or parameter estimates for 66 family-level clades regressed against the latitudinal mid-point of the family, analysed using Pearson's correlation (rP), with significant results (p-value) (see the electronic supplementary material for discussion of multiple comparisons).)
| latitude versus: | rP | p-value |
|---|---|---|
| species richness (ln) | −0.45 | 0.00014 |
| stem age (Ma) | 0.47 | 0.00008 |
| crown age (Ma) | −0.27 | 0.03277 |
| carrying capacity (K′) | −0.61 | <0.00001 |
| saturation (N/K′) | 0.36 | 0.00555 |
| r (lineages × Myr−1) | −0.42 | 0.00058 |
| ɛ (extinction/speciation) | 0.31 | 0.01412 |
| area (km2) | −0.40 | 0.00102 |
| NPP (g[C] × m2 × y−1) | −0.54 | <0.00001 |