Table 2.

Additive genetic and maternal effects (estimate ± s.e.) on offspring early life telomere length (TL) estimated by ‘animal model’ analyses. Six models (1–6) are presented, where the first one is the null model. The next models (2–4) show how variance is partitioned when factors are added to the null model, starting with brood (model 2), followed by maternal effect (model 3) and then genetic effect (model 4). The last two models (5–6) show how variance is partitioned when excluding brood but including first maternal effect (model 5) and then adding genetic effect (model 6). In all these models, ‘mother age’ is included as a fixed factor. Significance levels of the factors are estimated with log-likelihood (logL) ratio test and factors with p < 0.001 are indicated in bold. Degrees of freedom are 167 for all models. V_P, phenotypic variance; V_E, environmental (residual) variance; e², environmental (residual) effect; V_B, brood variance; b², brood effect; V_M, maternal variance; m², maternal effect; V_A, additive genetic variance; h², heritability; logL, log-likelihood estimate; *, model did not fully converge; n.e., not estimated.

model	VP	VE	e2	VB	b2	VM	m2	VA	h2	logL
1. TL = mother age	0.114 ± 0.012	0.114 ± 0.012	1	—	—	—	—	—	—	91.68
2. TL = mother age + brood	0.106 ± 0.016	0.015 ± 0.002	0.141 ± 0.029	0.091 ± 0.017	0.848 ± 0.029	—	—	—	—	172.5
3. TL = mother age + brood + maternal effect	0.106 ± 0.018	0.015 ± 0.002	0.141 ± 0.031	0.043 ± 0.020	0.405 ± 0.146	0.048 ± 0.014	0.454 ± 0.137	—	—	176.3
4. TL = mother age + brood + genetic effect + maternal effect*	0.091 ± 0.013	0 ± 0 (n.e.)	0 ± 0 (n.e.)	0.016 ± 0.015	0.184 ± 0.151	0.042 ± 0.013	0.467 ± 0.039	0.032 ± 0.004	0.349 ± 0.068	179.5
5. TL = Telomere length = mother age + maternal effect	0.112 ± 0.019	0.039 ± 0.005	0.351 ± 0.071	—	—	0.072 ± 0.020	0.650 ± 0.071	—	—	142.98
6. TL = mother age + genetic effect + maternal effect	0.110 ± 0.019	0.006 ± 0.008	0.051 ± 0.077	—	—	0.051 ± 0.017	0.470 ± 0.093	0.051 ± 0.015	0.480 ± 0.120	155.5