Table 8.
Observed amino acid replacements in SOD and expected values, assuming a covarion model
| Comparison | My | Amino acid differences
|
|
|---|---|---|---|
| Observed | Expected | ||
| 1. Drosophila subgenera | 55 ± 10 | 18 ± 3 | 19 ± 3 |
| 2. Drosophila–Chymomyza | 60 ± 10 | 23 ± 2 | 20 ± 4 |
| 3. Mammalian orders | 70 ± 10 | 27 ± 2 | 22 ± 4 |
| 4. Drosophila–Ceratitis | 100 ± 20 | 31 ± 2 | 28 ± 3 |
| 5. Monocot–dicot | 125 ± 20 | 28 ± 3 | 31 ± 5 |
| 6. Angiosperm–gymnosperm | 220 ± 30 | 29 ± 7 | 42 ± 5 |
| 7. Mammal–amphibian | 350 ± 50 | 49 ± 2 | 53 ± 6 |
| 8. Tetrapod–fish | 400 ± 50 | 44 ± 4 | 56 ± 7 |
| 9. Vertebrate–insect | 600 ± 100 | 59 ± 3 | 60 ± 6 |
| 10. Animal–yeast | 1100 ± 200 | 67 ± 4 | 66 ± 7 |
The expected values are obtained using the covarion model with the parameter values given in the text; they are averages of 40 computer simulations for each entry. The data are modified from Fitch and Ayala (19).