Recent discoveries in the field of epigenetics, the study of inheritance of traits that occur without changing the DNA sequence, have shown that chronological age in mammals correlates with epigenetic changes that accumulate during the lifetime of an individual.

In humans, this observation has led to the development of epigenetic clocks, which are now extensively used as biomarkers of aging. While these clocks work accurately from birth until death, they are set back to zero in each new generation.

Now, an international team co-led by the University of Georgia, the GEOMAR Helmholtz Centre for Ocean Research Kiel and the Technical University of Munich, shows that epigenetic clocks not only exist in plants, but that these clocks keep ticking accurately over many generations. In a new study published in the journal Science, the team describes how this clock can tell time with a resolution from decades to centuries, an accuracy that cannot be achieved with traditional DNA mutation-based clocks.