Evolution has devised countless remarkable solutions to diverse challenges. Understanding the mechanistic basis of these solutions provides insights into how biological systems can be subtly tweaked without maladaptive consequences. The knowledge gained from illuminating these mechanisms is equally important to our understanding of fundamental evolutionary mechanisms as it is to our hopes of developing truly rational plant breeding and synthetic biology. In particular, modern population genomic approaches are proving very powerful in the detection of candidate alleles for mediating consequential adaptations that can be tested functionally. Especially striking are signals gained from contexts involving genetic transfers between populations, closely related species, or indeed between kingdoms. Here we discuss two major classes of these scenarios, adaptive introgression and horizontal gene flow, illustrating discoveries made across kingdoms.

Department of Botany Faculty of Science Charles University Prague Benátská 2 128 01 Prague Czech Republic

Department of Cell and Developmental Biology John Innes Centre Norwich Research Park Norwich NR4 7UH United Kingdom

Institute of Botany The Czech Academy of Sciences Zámek 1 252 43 Průhonice Czech Republic

References provided by Crossref.org

Ploidy as a leaky reproductive barrier: mechanisms, rates and evolutionary significance of interploidy gene flow

Complex Polyploids: Origins, Genomic Composition, and Role of Introgressed Alleles

Interspecific introgression mediates adaptation to whole genome duplication