Mind the lag: understanding delayed genetic erosion

The delay between environmental changes and the corresponding genetic responses within populations is a common but surprisingly overlooked phenomenon in ecology, evolutionary and conservation genetics. This time lag problem can lead to erroneous conservation assessments when solely relying on genetic data. We identify population size, life-history traits, reproductive strategies and the severity of population decline as the main determinants of time lags, evaluate potential confounding factors affecting genetic parameters during time lags, and propose methodological approaches that allow controlling for them. Considering the current unprecedented rate of genetic diversity and species loss, we expect our novel interpretive and methodological framework for time lags to stimulate further research and discussion on the most appropriate approaches to analyse genetic diversity for conservation.