What are we missing about marine invasions? Filling in the gaps with evolutionary genomics

Research on invasion biology has been largely dominated by studies on the ecological effects of invasion events, although recently, evolutionary processes have been shown to be important to invasion success. This is largely attributed to novel genomic tools that provide new opportunities to unravel the natural history, taxonomy, and invasion pathways of invasive species, as well as the genetic basis of adaptive traits that allow them to expand within and beyond their native range. Despite these advances and the growing literature of genomic research on terrestrial pests, these tools have not been widely applied to marine invasive species. This is in part due to the perception that high levels of dispersal and connectivity in many invasive marine species can limit the opportunity for local adaptation. However, there is growing evidence that even in species with high dispersal potential, significant site-specific adaptation can occur. We review how these "omic" tools provide unprecedented opportunities to characterise the role of adaptive variation, physiological tolerance, and epigenetic processes in determining the success of marine invaders. Yet, rapid range expansion in invasions can confound the analysis of genomic data, so we also review how data should be properly analysed and carefully interpreted under such circumstances. Although there are a limited number of studies pioneering this research in marine systems, this review highlights how future studies can be designed to integrate ecological and evolutionary information. Such datasets will be imperative for the effective management of marine pests.