Table 4.
Sympatric Lines |
Allopatric Lines |
Origin Effect |
|||||
---|---|---|---|---|---|---|---|
Mean | SD | Mean | SD | Degrees of Freedom (numerator, denominator) | F Value | P Value | |
Premating isolation | 0.702 | 0.580 | 0.703 | 0.584 | 17,306 | 1.1462 | 0.3089 |
NCGI | 0.8938 | 0.0751 | 0.8644 | 0.0966 | 11,141 | 6.9568 | 2.561 × 10−9 |
CSP | 0.1488 | 1.5807 | 0.1434 | 1.7568 | 18,88 | 0.4602 | 0.9679 |
Postzygotic isolation | 0.5036 | 0.2687 | 0.5142 | 0.2824 | 12,203 | 2.2074 | 0.01262 |
Postzygotic isolation—embryonic lethality | 0.0905 | 0.1909 | 0.0905 | 0.1900 | 12,203 | 1.6188 | 0.08846 |
Postzygotic isolation—larval lethality | 0.2280 | 0.2231 | 0.2224 | 0.2388 | 12,203 | 1.3817 | 0.1767 |
Postzygotic isolation—pupal lethality | 0.2048 | 0.1923 | 0.2282 | 0.2058 | 12,203 | 0.6689 | 0.7801 |
Note.—Linear models show no difference at the strength of most types of RI between sympatric and allopatric pairs of lines. The only RIM that shows an origin effect is NCGI, whose significance is exclusively driven by the cross ♀D. yakuba × ♂D. santomea (Matute 2010). When this cross is excluded, the origin effect is not significant anymore (F10,123 = 1.7319, P = 0.0808).