Evolutionary geneticists have traditionally applied a comparative approach, where the relationships between closely related species (or between individuals of the same species) are determined by contrasting their DNA sequences. DNA retrieved from museum specimens, fossil remains and archeological findings -collectively known as ancient DNA (aDNA) – have added an exciting new dimension to evolutionary studies; instead of indirectly inferring the likely state of DNA sequences from former generations of extant organism or from extinct species, aDNA allows the direct inspection and timing of the changes that have happened in a given species or evolutionary lineage throughout time. The aDNA field has recently blossomed thanks to the advent of high-throughput sequencing (HTS), which has radically increased the amount of data that can be produced from ancient samples. Although herbaria are present almost ubiquitously in natural history museums, their collections have not been extensively used for aDNA studies, and especially not for whole-genome analysis. We are using this largely untapped source to address a broad range of evolutionary questions in three main research avenues.

• The dynamics of past plant-pathogen epidemics
• Identification and timing of key events in crop domestication
• Colonization of new ecological niches by invasive or introduced species