Table 6. Molecular detection of selection across codon sites at the ELA-DRA and DQA.
| Locus | Model comparison | df | Etosha | Kruger | ||||
| ω | χ2 | p- value | ω | χ2 | p- value | |||
| DRA | M0 v. M3 | 4 | 0.213 | 6.60E-04 | 1.000 | 0.249 | 3.80E-04 | 1.000 |
| M1a v. M2a | 2 | 2.40E-05 | 1.000 | 1.00E-04 | 1.000 | |||
| M7 v. M8 | 2 | −4.18 | 1.000 | 4.00E-04 | 1.000 | |||
| DQA | M0 v. M3 | 4 | 1.112 | 50.10 | 0.000 | 0.707 | 64.23 | 0.000 |
| M1a v. M2a | 2 | 13.36 | 0.001 | 10.99 | 0.004 | |||
| M7 v. M8 | 2 | 13.76 | 0.001 | 11.98 | 0.002 | |||
| DQAALL | M0 v. M3 | 4 | 1.082 | 51.68 | 0.000 | 0.681 | 59.14 | 0.000 |
| M1a v. M2a | 2 | 13.16 | 0.001 | 4.93 | 0.085 | |||
| M7 v. M8 | 2 | 14.56 | 0.001 | 7.54 | 0.023 | |||
Model comparisons and likelihood ratio tests (LRTs) were conducted to test for significant heterogeneity across sites (M3 v. M0) and positive selection (M1a v. M2a, M7 v. M8). Significance (p-value) of LRTs was determined by calculation of the chi-square test statistic (χ2) and degrees of freedom (df). Significant test results (p<0.05) are highlighted in boldface. Non-synonymous to synonymous substitution rates (ω) at each locus and population were estimated from M8 in PAML [100]. Estimates for the DQA locus are reported both excluding (DQA) and including (DQAALL) individuals with multi-locus genotypes.