Table 3. AIC ranking of models using IMa2 based on ∼300,000 sampled genealogies.
Model subscripts of population size (q) and migration (m) parameters identify populations used in the analysis; 0, 1, and 2 represent the estimated population sizes for Black-footed Albatrosses, Laysan Albatrosses, and the ancestral population, respectively. In each model brackets denote fixed parameters; other parameters were estimated.
| Model | Log(P) | k | AIC | Delta (AIC) |
w | q0 | q1 | q2 | M0>1 | M1>0 |
|---|---|---|---|---|---|---|---|---|---|---|
| Pop. size BF = LA; Mig. from LA to BF = 0 | 2.48 | 3 | 1.04 | 0.00 | 0.16 | 0.2388 | [0.2388] | 0.0085 | [0] | 0.2236 |
| Mig. from LA to BF = 0 | 3.39 | 4 | 1.22 | 0.18 | 0.15 | 0.2244 | 0.07 | 0.00087 | [0] | 2.5594 |
| Anc. pop. size = BF; Mig. from LA to BF = 0 | 2.16 | 3 | 1.68 | 0.64 | 0.12 | 0.3008 | 0.1094 | [0.3008] | [0] | 1.8228 |
| Anc pop. size = LA; Mig. from LA to BF = 0 | 2.16 | 3 | 1.69 | 0.65 | 0.12 | 0.3043 | 0.1101 | [0.1101] | [0] | 1.7566 |
| Mig. from BF to LA = mig. from LA to BF | 2.99 | 4 | 2.03 | 0.99 | 0.10 | 0.2465 | 0.1291 | 0.0026 | 0.1998 | [0.1998] |
| Pop. size LA = BF | 2.48 | 4 | 3.04 | 2.00 | 0.06 | 0.2388 | [0.2388] | 0.0085 | 0 | 0.2236 |
| Mig. from LA to BF = 0; Pop. size LA & BF = anc | 0.30 | 2 | 3.40 | 2.36 | 0.05 | 0.1761 | [0.1761] | [0.1761] | [0] | 1.4231 |
| Anc pop. Size = BF | 2.16 | 4 | 3.68 | 2.64 | 0.04 | 0.3008 | 0.1094 | [0.3008] | 0 | 1.8228 |
| LA pop. size = anc | 2.16 | 4 | 3.69 | 2.65 | 0.04 | 0.3043 | 0.1101 | [0.1101] | 0 | 1.7566 |
| BF pop. size = LA; Mig. from LA to BF = BF to LA | 0.93 | 3 | 4.15 | 3.11 | 0.03 | 0.2388 | [0.2388] | 0.0085 | 0.1034 | [0.1034] |
| Full model | 2.60 | 5 | 4.80 | 3.76 | 0.02 | 0.3394 | 0.1015 | 0.0171 | 0 | 1.6769 |
| BF pop. size = LA & anc | 0.30 | 3 | 5.40 | 4.36 | 0.02 | 0.1761 | [0.1761] | [0.1761] | 0 | 1.4231 |
| BF pop. size = LA; Both mig. = 0 | −0.83 | 2 | 5.66 | 4.62 | 0.02 | 0.2595 | [0.2595] | 0.5181 | [0] | [0] |
| Both mig. = 0 | −0.19 | 3 | 6.38 | 5.34 | 0.01 | 0.2509 | 0.2732 | 0.5181 | [0] | [0] |
| BF pop. size = LA & anc; Mig. From LA to BF = BF to LA | −1.21 | 2 | 6.42 | 5.38 | 0.01 | 0.2907 | [0.2907] | [0.2907] | 0.1121 | [0.1121] |
| LA pop. size = anc; Mig. from LA to BF = BF to LA | −0.69 | 3 | 7.38 | 6.34 | 0.01 | 0.2053 | 0.1214 | [0.1214] | 0.6553 | [0.6553] |
| BF pop. size = anc; Both mig. = 0 | −1.78 | 2 | 7.55 | 6.51 | 0.01 | 0.4489 | 0.3151 | [0.4489] | [0] | [0] |
| BF pop. size = LA; Mig. from BF to LA = 0 | −0.83 | 3 | 7.66 | 6.62 | 0.01 | 0.2595 | [0.2595] | 0.5181 | 0 | [0] |
| BF pop. size = anc; Mig. from LA to BF = BF to LA | −0.85 | 3 | 7.71 | 6.67 | 0.01 | 0.2568 | 0.1392 | [0.2568] | 0.2261 | [0.2261] |
| LA pop. size = anc; Mig. from BF to LA =0 | −0.86 | 3 | 7.73 | 6.69 | 0.01 | 0.4036 | 0.1815 | [0.1815] | 0.1434 | [0] |
| BF pop. size = LA & anc; Mig. from BF to LA = 0 | −2.06 | 2 | 8.13 | 7.09 | 0.00 | 0.2717 | [0.2717] | [0.2717] | 0.4307 | [0] |
| Mig. from BF to LA = 0 | −0.19 | 4 | 8.38 | 7.34 | 0.00 | 0.2509 | 0.2732 | 0.5181 | 0 | [0] |
| BF pop. size = anc; Mig. from BF to LA = 0 | −1.60 | 3 | 9.21 | 8.17 | 0.00 | 0.2659 | 0.0985 | [0.2659] | 1.0792 | [0] |
| LA pop. size = anc; Both mig. = 0 | −3.53 | 2 | 11.05 | 10.01 | 0.00 | 0.2509 | 0.2846 | [0.2846] | [0] | [0] |
| BF pop. size = LA & anc.; Both mig. = 0 | −4.97 | 1 | 11.94 | 10.90 | 0.00 | 0.2644 | [0.2644] | [0.2644] | [0] | [0] |