Table 3.
Comparison between generations
| Effect tested | Fixed effects | Random effects | AIC | χ2 | d.f. | P |
|---|---|---|---|---|---|---|
| D, G | P, P1, P2 | 3881.9 | ||||
| days (D) | G | P, P1, P2 | 11986.6 | 8116.7 | 6 | <0.001 |
| generation (G) | D | P, P1, P2 | 3891.6 | 13.7 | 2 | 0.001 |
| population (P) | D, G | P1, P2 | 4168.2 | 288.3 | 1 | <0.001 |
| parent 1 (P1) | D, G | P, P2 | 4421.1 | 541.1 | 1 | <0.001 |
| parent 2 (P2) | D, G | P, P1 | 4022.9 | 143 | 1 | <0.001 |
Likelihood ratio tests comparing generalized linear mixed models (GLMMs) on the effects of the number of days in experiment, generation (parental, F1 or F2), population (n = 1308), parental strain 1 (the same in both inter-and intraspecific crosses) and parental strain 2 on survival in deteriorating environments. Effect evaluation as in Table 1. To evaluate the significance of fixed and random effects, alternative models without the variable of interest were compared to the full model (bold) using likelihood ratio tests. If an alternative model had a significantly better fit (bold), this model was subsequently compared against further reduced models.