Table 1.
Relative Fit (ΔAICC) of Six Evolutionary Models Describing Gene Copy Number Variation at MHC Class I and Class II of Birds
| MHC | Evolution Model | AICC | ΔAICC | Relative Importance (ωi) |
|---|---|---|---|---|
| Class I | Time-dependent (early vs. late evolution) | 462.3 | 0.0 | 0.662 |
| Ornstein–Uhlenbeck | 464.2 | 1.9 | 0.301 | |
| Time-dependent (linear) | 468.5 | 6.2 | 0.036 | |
| Brownian motion adjusted for λ | 477.1 | 14.8 | <0.001 | |
| Brownian motion | 478.4 | 16.1 | <0.001 | |
| Time-dependent (exponential) | 480.6 | 18.3 | <0.001 | |
| Class II | Brownian motion adjusted for λ | 1,010.3 | 0.0 | 0.999 |
| Ornstein–Uhlenbeck | 1,038.8 | 28.5 | <0.001 | |
| Time-dependent (early vs. late evolution) | 1,094.6 | 84.3 | <0.001 | |
| Time-dependent (linear) | 1,120.1 | 109.8 | <0.001 | |
| Brownian motion | 1,150.1 | 139.8 | <0.001 | |
| Time-dependent (exponential) | 1,152.1 | 141.8 | <0.001 |
Note.—Relative importance of each model is assessed with Akaike weight (ωi).