RT Journal Article SR Electronic T1 Older fathers’ children have lower evolutionary fitness across four centuries and in four populations JF bioRxiv FD Cold Spring Harbor Laboratory SP 042788 DO 10.1101/042788 A1 Ruben C. Arslan A1 Kai P. Willführ A1 Emma Frans A1 Karin J. H. Verweij A1 Mikko Myrskylä A1 Eckart Voland A1 Catarina Almqvist A1 Brendan P. Zietsch A1 Lars Penke YR 2016 UL http://biorxiv.org/content/early/2016/03/08/042788.abstract AB Higher paternal age at offspring conception increases de novo genetic mutations (Kong et al., 2012). Based on evolutionary genetic theory we predicted that the offspring of older fathers would be less likely to survive and reproduce, i.e. have lower fitness. In a sibling control study, we find clear support for negative paternal age effects on offspring survival, mating and reproductive success across four large populations with an aggregate N > 1.3 million in main analyses. Compared to a sibling born when the father was 10 years younger, individuals had 4-13% fewer surviving children in the four populations. Three populations were pre-industrial (1670-1850) Western populations and showed a pattern of paternal age effects across the offspring’s lifespan. In 20th-century Sweden, we found no negative paternal age effects on child survival or marriage odds. Effects survived tests for competing explanations, including maternal age and parental loss. To the extent that we succeeded in isolating a mutation-driven effect of paternal age, our results can be understood to show that de novo mutations reduce offspring fitness across populations and time. We can use this understanding to predict the effect of increasingly delayed reproduction on offspring genetic load, mortality and fertility.