Table 1.
Relationship between macroevolutionary diversification rate (λ) and the rate of prezygotic and postzygotic evolution (ψ) for major clades of flies and birds
| Group | Model | Metric | Pearson correlation (P value) | Spearman correlation (P value) | PGLS slope | PGLS P value | df |
| Drosophila (pre) | Asymptotic | λ0 | 0.3 (0.43) | 0.23 (0.55) | 1.03 | 0.45 | 9(7) |
| Drosophila (pre) | Asymptotic | λ95 | 0.24 (0.53) | 0.58 (0.11) | 0.86 | 0.38 | 9(7) |
| Drosophila (post) | Linear | λ0 | −0.31 (0.42) | −0.08 (0.84) | −1.22 | 0.21 | 9(7) |
| Drosophila (post) | Linear | λ95 | −0.31 (0.41) | −0.10 (0.81) | −0.71 | 0.33 | 9(7) |
| Birds | Linear | λ | −0.01 (0.95) | 0.0 (0.98) | −0.01 | 0.81 | 30(28) |
| Birds | Linear | λMAX | −0.03 (0.8) | 0.05 (0.77) | −0.03 | 0.81 | 30(28) |
| Birds | Linear | λq80 | −0.03 (0.87) | 0.04 (0.82) | −0.01 | 0.77 | 30(28) |
| Birds | Asymptotic | λ | 0.04 (0.83) | 0.05 (0.79) | −0.01 | 0.67 | 30(28) |
| Birds | Asymptotic | λMAX | −0.01 (0.96) | 0.12 (0.54) | −0.04 | 0.7 | 30(28) |
| Birds | Asymptotic | λq80 | −0.01 (0.98) | 0.08 (0.66) | −0.01 | 0.73 | 30(28) |
Results are shown only for the best-fit functional models for the accumulation of RI with genetic distance (Table S1 and Fig. S1). Linear and asymptotic models were approximately equivalent for birds and results for both models are shown. For Drosophila, λ0 and λ95 are constant-rate estimators of the speciation rate assuming no extinction (λ0) or high extinction (λ95). For birds, λ is the mean speciation rate within each family, λMAX is the maximum observed rate within each family, and λq80 is the estimated 0.80 quantile of the distribution of rates for each family. Avian results are shown only for the Hackett backbone topology; results for Ericson topology and for all other models are given in Table S3. The BAMM model used for the avian dataset estimates speciation rates separately from extinction rates.