Abstract
Past biological invasions have contributed to shaping our present day biodiversity. For many island ecosystems, they are the only source of terrestrial life. At the same time, biological invasions, in particular when caused by human activity, are a major concern for the conservation of native species. It is therefore essential to understand the drivers of biological invasions as well as the role invasions have played in different ecosystems. Molecular tools have provided valuable data to reconstruct biological invasions, their drivers, and their impacts. Recent technological developments have further increased the potential of molecular tools to track past shifts in biodiversity. Here, we provide a perspective on how such molecular tools have influenced our understanding of past biological invasions and discuss how they may further help to shape our understanding and management of biological invasions.