Parental age effects on offspring telomere length
We tested whether maternal age at conception (MAC [mean 1.8±1.1 S.D.
years, range 1-7 years], n =373 mothers with n =1967
offspring) or paternal age at conception (PAC [mean 2.1±1.2 S.D.
years, range 1-8 years], n =388 fathers with n =1927
offspring) predicted TL in offspring from Hestmannøy and Træna. We
applied within-subject centering (van de Pol & Wright, 2009) to
separate within-parental age effects (e.g. senescence) from
between-parental age effects (e.g. selective disappearance), by
including both the mean parental age at conception and the deviation
from the mean parental age for each parent as fixed effects in two LMMs
(for fathers and mothers, respectively) explaining variation in
offspring TL (log10-transformed). Both models included
island identity and sampling age as fixed effects, and random intercepts
for year and either maternal identity or paternal identity.