Table 1.
Results of phylogenetic analysis
| Pairing | Covariations | λ | LRT |
|---|---|---|---|
| Exon 2 | |||
| 793–797/833–837 | 1 | 5.00 (2.13) | 18.01 (6.82) |
| 803–805/813–815 | 1 | 3.65 (3.60) | 8.27 (11.22) |
| 838–841/845–848 | 2 | 5.77 (3.20) | 15.77 (13.06) |
| 853–855/859–861 | 2 | 2.46 (2.44) | 4.71 (6.54) |
| Exon 2/3′ UTR | |||
| 810–812/1762–1764 | 1 | 3.54 (3.82) | 7.88 (12.83) |
| 817–819/1756–1758 | 1 | 4.34 (2.10) | 8.34 (4.20) |
| Entire structure | 8 | 3.94 (2.69) | 61.39 (51.53) |
The first column shows the coordinates of the pairing regions [according to Kreitman (17)]. The second column contains the number of covariations found for the 12 sequences aligned in Fig. 2. The third and fourth columns give the values of the pairing parameter (λ) and of the likelihood-ratio-test (LRT) statistic, respectively (15). Values are given for an alignment of the 10 Drosophila sequences and for the 10 Drosophila plus the two medfly sequences (in parantheses). The values for the entire structure (with six pairings) are presented in the last line. Note that when sites evolve independently, the pairing parameter is λ = 1; λ > 1 indicates Watson–Crick base pairing.