Heritabilities and genetic correlations of telomere length, tarsus
length, and body condition
We found non-zero additive genetic variances (VA )
for TL (VA =0.009, HPD=[0.008, 0.010]), tarsus
length (VA =0.190, HPD=[0.116, 0.315]) and
body condition (VA =0.006, HPD=[0.005, 0.006])
in the natural populations (Table 2, Fig. 3). The main component
contributing to variance in TL was between-year differences
(VY , explaining 70% of the variance), while
maternal (VM , 8%), paternal
(VF , 7%), and brood variances
(VB , 6%) also explained considerable proportions
of the total phenotypic variance (Fig. 3). Combined, these environmental
effects captured 91% of the phenotypic variance in TL. For tarsus
length and condition, the main variance components were among different
broods (38%) and among years (77%), respectively (Table 2, Fig. 3).
The heritabilities were h2 =0.042 for TL
(HPD=[0.024, 0.064]), h2 =0.076
(HPD=[0.045, 0.123]) for tarsus length, andh2 =0.028 (HPD=[0.016, 0.0.043]) for body
condition. The heritability estimates were of the same magnitude in the
univariate animal models (Table S2.1). There was no evidence for a
genetic correlation between TL and tarsus length
(rA =-0.017, HPD=[-0.120, 0.091]) or between
TL and condition (rA =-0.010, HPD=[-0.079,
0.060]).
Parent-offspring regressions showed a large maternal inheritance
component in TL
(h2maternal =0.45±0.16,
CI=[0.136, 0.758]), but no paternal inheritance (Fig. S2.2).
Including parental genetic effects in a multivariate animal model
confirmed slightly higher maternal
(h2maternal =0.078,
HPD=[0.042, 0.104]) than paternal heritability of TL
(h2paternal =0.070,
HPD=[0.038, 0.094], Table S2.2). We found no evidence of differences
in sex-specific heritabilities of TL (Table S2.3).
In the analyses of the artificially selected populations (Leka and Vega,
Table S2.4) we found comparable heritability estimates for TL
(h2 =0.035, HPD=[0.008, 0.084]) and body
condition (h2 =0.019, HPD=[0.004, 0.050]),
and a slightly higher estimate for tarsus length
(h2 =0.114, HPD=[0.045, 0.247]). Similarly,
there was no evidence for genetic correlations between TL and tarsus
(rA =-0.027, HPD=[-0.224, 0.181]) or between
TL and body condition (rA =-0.006, HPD=[-0.130,
0.134], Table S2.4).