Table 1.
Statistical description of individual datasets (the twelve genes on the mitochondrial H-strand) and of concatenated datasets (AL). L (bp): length of the gene in base pairs. No cst: number of constant sites in the alignment. No info: number of informative sites in the alignment. AIC: Model selected according to AIC criterion in Modeltest, which always included parameters G (a gamma distribution of substitution rates) and I (a proportion of invariable sites). χ2 (1, 2): chi square test for homogeneity of base frequencies across species on datasets with third codon position removed (P = 1.0 in every case). χ2 (1, 2, 3): chi square test on datasets with codon positions 1, 2 and 3 included.
| Datasets | L (bp) | No cst (%) | No info (%) | AIC | χ2 (1, 2) | χ2 (1, 2, 3) |
|---|---|---|---|---|---|---|
| ATP6 | 452 | 200 (44.2) | 204 (45.1) | GTRa | 78.25 | 419.99* |
| ATP8 | 60 | 10 (16.7) | 47 (78.3) | TrNb | 145.87 | 198.83 |
| COX1 | 1022 | 780 (76.3) | 157 (15.4) | GTR | 15.85 | 573.75* |
| COX2 | 440 | 247 (56.1) | 150 (34.1) | TVMc | 28.26 | 290.95 |
| COX3 | 522 | 339 (64.9) | 137 (26.2) | TVM | 33.42 | 320.19 |
| CYTB | 754 | 402 (53.3) | 276 (36.6) | TIMd | 80.04 | 525.82* |
| NAD1 | 618 | 312 (50.5) | 239 (38.7) | GTR | 69.18 | 484.12* |
| NAD2 | 690 | 173 (25.1) | 463 (67.1) | GTR | 129.20 | 623.00* |
| NAD3 | 230 | 109 (47.4) | 100 (43.5) | TrN | 78.92 | 251.49 |
| NAD4 | 918 | 380 (41.4) | 458 (49.9) | GTR | 96.29 | 681.88* |
| NAD4 L | 192 | 69 (35.9) | 105 (54.7) | TVM | 65.08 | 251.49 |
| NAD5 | 1202 | 463 (38.5) | 619 (51.5) | GTR | 136.64 | 919.59* |
| ALL | 7100 | 3484 (49.1) | 2955 (41.6) | GTR | 267.78 | 4107.63* |