The aetiology of frailty remains unknown. It has been hypothesised that individual differences in epigenetic mechanisms, particularly DNA methylation (DNAm), may help to explain why some individuals become frail while others do not. Relating epigenetic measures to transitions in age-related frailty in individual patients requires longitudinal studies over many years. To overcome this barrier, we study associations between DNAm...

Understanding the maintenance of genetic variation in natural populations is a core aim of evolutionary genetics. Insight can be gained by quantifying selection at the level of the genotype, as opposed to the phenotype. Here, we show that in a natural population of Soay sheep which is polymorphic for coat pattern, recessive genetic variants at the causal gene, agouti signalling protein ( ASIP ) are associated with reduced life...